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Wang ZJ, Kong X, Huang Y, Li J, Bao L, Cao K, Hu Y, Cai J, Wang L, Chen H, Wu Y, Zhang Y, Pang F, Cheng Z, Babor P, Kolibal M, Liu Z, Chen Y, Zhang Q, Cui Y, Liu K, Yang H, Bao X, Gao HJ, Liu Z, Ji W, Ding F, Willinger MG. Conversion of chirality to twisting via sequential one-dimensional and two-dimensional growth of graphene spirals. Nat Mater 2024; 23:331-338. [PMID: 37537355 DOI: 10.1038/s41563-023-01632-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 07/10/2023] [Indexed: 08/05/2023]
Abstract
The properties of two-dimensional (2D) van der Waals materials can be tuned through nanostructuring or controlled layer stacking, where interlayer hybridization induces exotic electronic states and transport phenomena. Here we describe a viable approach and underlying mechanism for the assisted self-assembly of twisted layer graphene. The process, which can be implemented in standard chemical vapour deposition growth, is best described by analogy to origami and kirigami with paper. It involves the controlled induction of wrinkle formation in single-layer graphene with subsequent wrinkle folding, tearing and re-growth. Inherent to the process is the formation of intertwined graphene spirals and conversion of the chiral angle of 1D wrinkles into a 2D twist angle of a 3D superlattice. The approach can be extended to other foldable 2D materials and facilitates the production of miniaturized electronic components, including capacitors, resistors, inductors and superconductors.
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Affiliation(s)
- Zhu-Jun Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China.
- School of Natural Sciences, Technical University Munich, Munich, Germany.
- Center for Transformative Science, ShanghaiTech University, Shanghai, China.
| | - Xiao Kong
- Institute of Technology for Carbon Neutrality, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yuan Huang
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
- Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing, China
| | - Jun Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, China
| | - Lihong Bao
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Kecheng Cao
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Yuxiong Hu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Jun Cai
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Lifen Wang
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Hui Chen
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Yueshen Wu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, China
| | - Yiwen Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, China
| | - Fei Pang
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, China
| | - Zhihai Cheng
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, China
| | - Petr Babor
- Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic
- Central European Institute of Technology (CEITEC), Brno University of Technology, Brno, Czech Republic
| | - Miroslav Kolibal
- Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic
- Central European Institute of Technology (CEITEC), Brno University of Technology, Brno, Czech Republic
| | - Zhongkai Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
- Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing, China
| | - Yulin Chen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
- Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing, China
- Department of Physics, University of Oxford, Oxford, UK
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - Qiang Zhang
- Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Yi Cui
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China
| | - Kaihui Liu
- State Key Laboratory for Mesoscopic Physics, Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, China
- International Center for Quantum Materials, Collaborative Innovation Center of Quantum Matter, Peking University, Beijing, China
| | - Haitao Yang
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Xinhe Bao
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Hong-Jun Gao
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
- School of Physical Sciences, University of the Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Topological Quantum Computation, University of the Chinese Academy of Sciences, Beijing, China
| | - Zhi Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
- Center for Transformative Science, ShanghaiTech University, Shanghai, China
| | - Wei Ji
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, China.
| | - Feng Ding
- Institute of Technology for Carbon Neutrality, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China.
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Birkner L, Foreta M, Rinaldi A, Orekhov A, Willinger MG, Eichelbaum M. Dynamic accelerated stress test and coupled on-line analysis program to elucidate aging processes in proton exchange membrane fuel cells. Sci Rep 2024; 14:3999. [PMID: 38369606 PMCID: PMC10874950 DOI: 10.1038/s41598-024-54258-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 02/10/2024] [Indexed: 02/20/2024] Open
Abstract
The application of hydrogen proton exchange membrane fuel cells (PEMFC) in greenhouse gas emission free heavy-duty vehicles requires extremely durable PEMFC components with service lives in the range of 30,000 h. Hence suitable test and analysis methods are required that reflect realistic operation scenarios, but significantly accelerate aging. For this purpose, a dynamic accelerated stress test was developed, which is coupled with a comprehensive in-depth in-situ and ex-situ analysis program to determine the aging processes of a PEMFC membrane electrode assembly (MEA). The test comprehends dynamic cycling between low, moderate and high load, different temperature and humidity conditions as well as recovery sequences to distinguish between reversible and irreversible failure modes. All phases of the PEMFC system (i.e. solid, liquid and gaseous) are monitored on-line during aging by sophisticated electrochemical, mass spectrometric and ion chromatographic analytical methods. The structural and elemental composition of the MEA before and after the aging program (post-mortem) are investigated by X-ray fluorescence, scanning and transmission electron microscopy. This program was able to age a commercial PEMFC to end-of-life in 1000 h, while providing an accurate picture of the aging processes involved.
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Affiliation(s)
- Lena Birkner
- Nuremberg Institute of Technology, Institute for Applied Hydrogen Research, Electro- and Thermochemical Energy Systems (H2OHM), 90489, Nuremberg, Germany
- MAN Truck & Bus SE, Material Technology and Applied Chemistry (EOMC), 90441, Nuremberg, Germany
| | - Michael Foreta
- MAN Truck & Bus SE, Material Technology and Applied Chemistry (EOMC), 90441, Nuremberg, Germany
| | - Ali Rinaldi
- Technical University of Munich, Chair of Electron Microscopy, 85748, Garching, Germany
| | - Anton Orekhov
- Technical University of Munich, Chair of Electron Microscopy, 85748, Garching, Germany
| | - Marc-Georg Willinger
- Technical University of Munich, Chair of Electron Microscopy, 85748, Garching, Germany
| | - Maik Eichelbaum
- Nuremberg Institute of Technology, Institute for Applied Hydrogen Research, Electro- and Thermochemical Energy Systems (H2OHM), 90489, Nuremberg, Germany.
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3
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Brack E, Plodinec M, Willinger MG, Copéret C. Implications of Ga promotion and metal-oxide interface from tailored PtGa propane dehydrogenation catalysts supported on carbon. Chem Sci 2023; 14:12739-12746. [PMID: 38020386 PMCID: PMC10646969 DOI: 10.1039/d3sc04711c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/02/2023] [Indexed: 12/01/2023] Open
Abstract
Propane Dehydrogenation is a key technology, where Pt-based catalysts have widely been investigated in industry and academia, with development exploring the use of promoters (Sn, Zn, Ga, etc.) and additives (Na, K, Ca, Si, etc.) towards improved catalytic performances. Recent studies have focused on the role of Ga promotion: while computations suggest that Ga plays a key role in enhancing catalytic selectivity and stability of PtGa catalysts through Pt-site isolation as well as morphological changes, experimental evidence are lacking because of the use of oxide supports that prevent more detailed investigation. Here, we develop a methodology to generate Pt and PtGa nanoparticles with tailored interfaces on carbon supports by combining surface organometallic chemistry (SOMC) and specific thermolytic molecular precursors containing or not siloxide ligands. This approach enables the preparation of supported nanoparticles, exhibiting or not an oxide interface, suitable for state-of-the art electron microscopy and XANES characterization. We show that the introduction of Ga enables the formation of homogenously alloyed, amorphous PtGa nanoparticles, in sharp contrast to highly crystalline monometallic Pt nanoparticles. Furthermore, the presence of an oxide interface is shown to stabilize the formation of small particles, at the expense of propene selectivity loss (formation of cracking side-products, methane/ethene), explaining the use of additives such as Na, K and Ca in industrial catalysts.
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Affiliation(s)
- Enzo Brack
- Department of Chemistry and Applied Biosciences ETH Zurich Vladimir Prelog Weg 2/10 CH-8093 Zurich Switzerland
| | - Milivoj Plodinec
- Department of Chemistry and Applied Biosciences ETH Zurich Vladimir Prelog Weg 2/10 CH-8093 Zurich Switzerland
- Scientific Center for Optical and Electron Microscopy (ScopeM) ETH Zurich Otto-Stern-Weg 3 CH-8093 Zurich Switzerland
| | - Marc-Georg Willinger
- Scientific Center for Optical and Electron Microscopy (ScopeM) ETH Zurich Otto-Stern-Weg 3 CH-8093 Zurich Switzerland
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences ETH Zurich Vladimir Prelog Weg 2/10 CH-8093 Zurich Switzerland
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Niu Y, Wang Y, Chen J, Li S, Huang X, Willinger MG, Zhang W, Liu Y, Zhang B. Patterning the consecutive Pd 3 to Pd 1 on Pd 2Ga surface via temperature-promoted reactive metal-support interaction. Sci Adv 2022; 8:eabq5751. [PMID: 36490336 PMCID: PMC9733920 DOI: 10.1126/sciadv.abq5751] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 11/03/2022] [Indexed: 06/17/2023]
Abstract
Atom-by-atom control of a catalyst surface is a central yet challenging topic in heterogeneous catalysis, which enables precisely confined adsorption and oriented approach of reactant molecules. Here, exposed surfaces with either consecutive Pd trimers (Pd3) or isolated Pd atoms (Pd1) are architected for Pd2Ga intermetallic nanoparticles (NPs) using reactive metal-support interaction (RMSI). At elevated temperatures under hydrogen, in situ atomic-scale transmission electron microscopy directly visualizes the refacetting of Pd2Ga NPs from energetically favorable (013)/(020) facets to (011)/(002). Infrared spectroscopy and acetylene hydrogenation reaction complementarily confirm the evolution from consecutive Pd3 to Pd1 sites of Pd2Ga catalysts with the concurrent fingerprinting CO adsorption and featured reactivities. Through theoretical calculations and modeling, we reveal that the restructured Pd2Ga surface results from the preferential arrangement of additionally reduced Ga atoms on the surface. Our work provides previously unidentified mechanistic insight into temperature-promoted RMSI and possible solutions to control and rearrange the surface atoms of supported intermetallic catalyst.
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Affiliation(s)
- Yiming Niu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
- Department of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
| | - Yongzhao Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
- Department of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
| | - Junnan Chen
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
- Department of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
| | - Shiyan Li
- Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Xing Huang
- Scientific Center for Optical and Electron Microscopy, ETH Zurich, Otto-Stern-Weg 3, Zurich 8093, Switzerland
- College of Chemistry, Fuzhou University, Fuzhou 36108, China
| | - Marc-Georg Willinger
- Scientific Center for Optical and Electron Microscopy, ETH Zurich, Otto-Stern-Weg 3, Zurich 8093, Switzerland
- School of Natural Science (NAT), Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, Garching 85747, Germany
| | - Wei Zhang
- School of Materials Science and Engineering, Key Laboratory of Automobile Materials MOE, and Electron Microscopy Center, Jilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy Materials, Jilin University, Changchun 130012, China
| | - Yuefeng Liu
- Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Bingsen Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
- Department of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
- Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
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5
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Beck A, Kazazis D, Ekinci Y, Li X, Müller Gubler EA, Kleibert A, Willinger MG, Artiglia L, van Bokhoven JA. The Extent of Platinum-Induced Hydrogen Spillover on Cerium Dioxide. ACS Nano 2022; 17:1091-1099. [PMID: 36469418 DOI: 10.1021/acsnano.2c08152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Hydrogen spillover from metal nanoparticles to oxides is an essential process in hydrogenation catalysis and other applications such as hydrogen storage. It is important to understand how far this process is reaching over the surface of the oxide. Here, we present a combination of advanced sample fabrication of a model system and in situ X-ray photoelectron spectroscopy to disentangle local and far-reaching effects of hydrogen spillover in a platinum-ceria catalyst. At low temperatures (25-100 °C and 1 mbar H2) surface O-H formed by hydrogen spillover on the whole ceria surface extending microns away from the platinum, leading to a reduction of Ce4+ to Ce3+. This process and structures were strongly temperature dependent. At temperatures above 150 °C (at 1 mbar H2), O-H partially disappeared from the surface due to its decreasing thermodynamic stability. This resulted in a ceria reoxidation. Higher hydrogen pressures are likely to shift these transition temperatures upward due to the increasing chemical potential. The findings reveal that on a catalyst containing a structure capable to promote spillover, hydrogen can affect the whole catalyst surface and be involved in catalysis and restructuring.
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Affiliation(s)
- Arik Beck
- ETH Zurich, Vladimir-Prelog Weg 1, Zürich8093, Switzerland
| | - Dimitrios Kazazis
- Paul Scherrer Institute, Forschungsstrasse 111, 5232Villigen, Switzerland
| | - Yasin Ekinci
- Paul Scherrer Institute, Forschungsstrasse 111, 5232Villigen, Switzerland
| | - Xiansheng Li
- ETH Zurich, Vladimir-Prelog Weg 1, Zürich8093, Switzerland
- Paul Scherrer Institute, Forschungsstrasse 111, 5232Villigen, Switzerland
| | | | - Armin Kleibert
- Paul Scherrer Institute, Forschungsstrasse 111, 5232Villigen, Switzerland
| | | | - Luca Artiglia
- Paul Scherrer Institute, Forschungsstrasse 111, 5232Villigen, Switzerland
| | - Jeroen A van Bokhoven
- ETH Zurich, Vladimir-Prelog Weg 1, Zürich8093, Switzerland
- Paul Scherrer Institute, Forschungsstrasse 111, 5232Villigen, Switzerland
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6
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Huang X, Beck A, Fedorov A, Frey H, Zhang B, Klötzer B, van Bokhoven JA, Copéret C, Willinger MG. Visualizing Structural and Chemical Transformations of an Industrial Cu/ZnO/Al2O3 Pre‐catalyst during Activation and CO2 Reduction. ChemCatChem 2022. [DOI: 10.1002/cctc.202201280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Xing Huang
- Fuzhou University College of Chemistry Wulong River North Street 2 350108 Fuzhou CHINA
| | - Arik Beck
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Department of Chemistry and Applied Biosciences SWITZERLAND
| | - Alexey Fedorov
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Department of Mechanical and Process Engineering SWITZERLAND
| | - Hannes Frey
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Scientific Center for Optical and Electron Microscopy SWITZERLAND
| | - Bingsen Zhang
- Institute of Metal Research Chinese Academy of Sciences Shenyang National Laboratory for Materials Science CHINA
| | - Bernhard Klötzer
- University of Innsbruck: Universitat Innsbruck Department of Physical Chemistry AUSTRIA
| | - Jeroen A. van Bokhoven
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Department of Chemistry and Applied Biosciences SWITZERLAND
| | - Christophe Copéret
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Department of Chemistry and Applied Biosciences SWITZERLAND
| | - Marc-Georg Willinger
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Scientific Center for Optical and Electron Microscopy CHINA
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Frey H, Beck A, Huang X, van Bokhoven JA, Willinger MG. Dynamic interplay between metal nanoparticles and oxide support under redox conditions. Science 2022; 376:982-987. [PMID: 35617409 DOI: 10.1126/science.abm3371] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The dynamic interactions between noble metal particles and reducible metal-oxide supports can depend on redox reactions with ambient gases. Transmission electron microscopy revealed that the strong metal-support interaction (SMSI)-induced encapsulation of platinum particles on titania observed under reducing conditions is lost once the system is exposed to a redox-reactive environment containing oxygen and hydrogen at a total pressure of ~1 bar. Destabilization of the metal-oxide interface and redox-mediated reconstructions of titania lead to particle dynamics and directed particle migration that depend on nanoparticle orientation. A static encapsulated SMSI state was reestablished when switching back to purely oxidizing conditions. This work highlights the difference between reactive and nonreactive states and demonstrates that manifestations of the metal-support interaction strongly depend on the chemical environment.
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Affiliation(s)
- H Frey
- Scientific Center of Optical and Electron Microscopy (ScopeM), ETH Zürich, 8093 Zürich, Switzerland.,Institute for Chemical and Bioengineering, ETH Zürich, 8093 Zürich, Switzerland
| | - A Beck
- Institute for Chemical and Bioengineering, ETH Zürich, 8093 Zürich, Switzerland.,Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - X Huang
- Scientific Center of Optical and Electron Microscopy (ScopeM), ETH Zürich, 8093 Zürich, Switzerland.,College of Chemistry, Fuzhou University, Fuzhou 350116, P. R. China
| | - J A van Bokhoven
- Institute for Chemical and Bioengineering, ETH Zürich, 8093 Zürich, Switzerland.,Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - M G Willinger
- Scientific Center of Optical and Electron Microscopy (ScopeM), ETH Zürich, 8093 Zürich, Switzerland
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Fan H, Qiu L, Fedorov A, Willinger MG, Ding F, Huang X. Dynamic State and Active Structure of Ni-Co Catalyst in Carbon Nanofiber Growth Revealed by in Situ Transmission Electron Microscopy. ACS Nano 2021; 15:17895-17906. [PMID: 34730325 DOI: 10.1021/acsnano.1c06189] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Alloy catalysts often show superior effectiveness in the growth of carbon nanotubes/nanofibers (CNTs/CNFs) as compared to monometallic catalysts. However, due to the lack of an understanding of the active state and active structure, the origin of the superior performance of alloy catalysts is unknown. In this work, we report an in situ transmission electron microscopy (TEM) study of the CNF growth enabled by one of the most active known alloy catalysts, i.e., Ni-Co, providing insights into the active state and the interaction between Ni and Co in the working catalyst. We reveal that the functioning catalyst is highly dynamic, undergoing constant reshaping and periodic elongation/contraction. Atomic-scale imaging combined with in situ electron energy-loss spectroscopy further identifies the active structure as a Ni-Co metallic alloy (face-centered cubic, FCC). Aided by the molecular dynamics simulation and density functional theory calculations, we rationalize the dynamic behavior of the catalyst and the growth mechanism of CNFs and provide insight into the origin of the superior performance of the Ni-Co alloy catalyst.
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Affiliation(s)
- Hua Fan
- College of Chemistry, Fuzhou University, Wulong River North Street 2, 350108 Fuzhou, People's Republic of China
- Office of Science and Technology, Fuzhou University, Wulong River North Street 2, 350108 Fuzhou, People's Republic of China
| | - Lu Qiu
- Center for Multidimensional Carbon Materials, Institute for Basic Science, 50 UNIST-gil, Eonyang-eup, Ulju-gun, 44919 Ulsan, South Korea
| | - Alexey Fedorov
- Department of Mechanical and Process Engineering, ETH Zurich, Leonhardstrasse 21, 8092 Zurich, Switzerland
| | - Marc-Georg Willinger
- Scientific Center for Optical and Electron Microscopy, ETH Zurich, Otto-Stern-Weg 3, 8093 Zurich, Switzerland
| | - Feng Ding
- Center for Multidimensional Carbon Materials, Institute for Basic Science, 50 UNIST-gil, Eonyang-eup, Ulju-gun, 44919 Ulsan, South Korea
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Eonyang-eup, Ulju-gun, 44919 Ulsan, South Korea
| | - Xing Huang
- College of Chemistry, Fuzhou University, Wulong River North Street 2, 350108 Fuzhou, People's Republic of China
- Scientific Center for Optical and Electron Microscopy, ETH Zurich, Otto-Stern-Weg 3, 8093 Zurich, Switzerland
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9
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Huang X, Jones T, Fedorov A, Farra R, Copéret C, Schlögl R, Willinger MG. Phase Coexistence and Structural Dynamics of Redox Metal Catalysts Revealed by Operando TEM. Adv Mater 2021; 33:e2101772. [PMID: 34117665 DOI: 10.1002/adma.202101772] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/10/2021] [Indexed: 05/12/2023]
Abstract
Metal catalysts play an important role in industrial redox reactions. Although extensively studied, the state of these catalysts under operating conditions is largely unknown, and assignments of active sites remain speculative. Herein, an operando transmission electron microscopy study is presented, which interrelates the structural dynamics of redox metal catalysts to their activity. Using hydrogen oxidation on copper as an elementary redox reaction, it is revealed how the interaction between metal and the surrounding gas phase induces complex structural transformations and drives the system from a thermodynamic equilibrium toward a state controlled by the chemical dynamics. Direct imaging combined with the simultaneous detection of catalytic activity provides unparalleled structure-activity insights that identify distinct mechanisms for water formation and reveal the means by which the system self-adjusts to changes of the gas-phase chemical potential. Density functional theory calculations show that surface phase transitions are driven by chemical dynamics even when the system is far from a thermodynamic phase boundary. In a bottom-up approach, the dynamic behavior observed here for an elementary reaction is finally extended to more relevant redox reactions and other metal catalysts, which underlines the importance of chemical dynamics for the formation and constant re-generation of transient active sites during catalysis.
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Affiliation(s)
- Xing Huang
- Scientific Center for Optical and Electron Microscopy, ETH Zurich, Otto-Stern-Weg 3, Zurich, 8093, Switzerland
- College of Chemistry, Fuzhou University, Fuzhou, 350116, P. R. China
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5, Zurich, 8093, Switzerland
- Fritz-Haber Institute of Max-Planck Society, Faradayweg 4-6, 14195, Berlin, Germany
| | - Travis Jones
- Fritz-Haber Institute of Max-Planck Society, Faradayweg 4-6, 14195, Berlin, Germany
| | - Alexey Fedorov
- Department of Mechanical and Process Engineering, ETH Zurich, Leonhardstrasse 21, 8092, Zurich, Switzerland
| | - Ramzi Farra
- Fritz-Haber Institute of Max-Planck Society, Faradayweg 4-6, 14195, Berlin, Germany
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5, Zurich, 8093, Switzerland
| | - Robert Schlögl
- Fritz-Haber Institute of Max-Planck Society, Faradayweg 4-6, 14195, Berlin, Germany
- Department Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, 45470, Mülheim an der Ruhr, Germany
| | - Marc-Georg Willinger
- Scientific Center for Optical and Electron Microscopy, ETH Zurich, Otto-Stern-Weg 3, Zurich, 8093, Switzerland
- Fritz-Haber Institute of Max-Planck Society, Faradayweg 4-6, 14195, Berlin, Germany
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10
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Baghizadeh A, Vaghefi PM, Huang X, Borme J, Almeida B, Salak AN, Willinger MG, Amaral VB, Vieira JM. Interplay of Magnetic Properties and Doping in Epitaxial Films of h-REFeO 3 Multiferroic Oxides. Small 2021; 17:e2005700. [PMID: 33619871 DOI: 10.1002/smll.202005700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/07/2021] [Indexed: 06/12/2023]
Abstract
Multiferroic materials demonstrating coexistence of magnetic and ferroelectric orders are promising candidates for magnetoelectric devices. While understanding the underlying mechanism of interplaying of ferroic properties is important, tailoring their properties to make them potential candidates for magnetoelectric devices is challenging. Here, the antiferromagnetic Neel ordering temperature above 200 K is realized in successfully stabilized epitaxial films of (Lu,Sc)FeO3 multiferroic oxide. The first-principles calculations show the shrinkage of in-plane lattice constants of the unit cells of the films on different substrates which corroborates well the enhancement of the Neel ordering temperature (TN ). The profound effect of lattice strain/stress at the interface due to differences of in-plane lattice constants on out of plane magnetic properties and on spin reorientation temperature in the antiferromagnetic region is further elucidated in the epitaxial films with and without buffer layer of Mn-doped LuFeO3 . Writing and reading ferroelectric domains reveal the ferroelectric response of the films at room temperature. Detailed electron microscopy shows the presence of lattice defects in atomic scale. First-principles calculations show that orbital rehybridization of rare-earth ions and oxygen is one of the main driving force of ferroelectricity along c-axis in thin films of hexagonal ferrites.
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Affiliation(s)
- Ali Baghizadeh
- Department of Materials and Ceramics Engineering, CICECO - Aveiro Institute of Materials, University of Aveiro, Aveiro, 3810-193, Portugal
- Scientific Center for Optical and Electron Microscopy (ScopeM), ETH Zurich, Zurich, 8093, Switzerland
| | - Pegah Mirzadeh Vaghefi
- EMPA, Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, 8600, Switzerland
| | - Xing Huang
- Scientific Center for Optical and Electron Microscopy (ScopeM), ETH Zurich, Zurich, 8093, Switzerland
| | - Jerome Borme
- International Iberian Nanotechnology Laboratory (INL), Braga, 4715-330, Portugal
| | - Bernardo Almeida
- Center and Department of Physics, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal
| | - Andrei N Salak
- Department of Materials and Ceramics Engineering, CICECO - Aveiro Institute of Materials, University of Aveiro, Aveiro, 3810-193, Portugal
| | - Marc-Georg Willinger
- Scientific Center for Optical and Electron Microscopy (ScopeM), ETH Zurich, Zurich, 8093, Switzerland
| | - Vitor B Amaral
- Department of Physics and CICECO - Aveiro Institute of Materials, University of Aveiro, Aveiro, 3810-193, Portugal
| | - Joaquim M Vieira
- Department of Materials and Ceramics Engineering, CICECO - Aveiro Institute of Materials, University of Aveiro, Aveiro, 3810-193, Portugal
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11
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Liu P, Abdala PM, Goubert G, Willinger MG, Copéret C. Ultrathin Single Crystalline MgO(111) Nanosheets*. Angew Chem Int Ed Engl 2020; 60:3254-3260. [PMID: 33137235 DOI: 10.1002/anie.202013196] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/26/2020] [Indexed: 11/11/2022]
Abstract
Synthesizing high-quality two-dimensional nanomaterials of nonlayered metal oxide is a challenge, especially when long-range single-crystallinity and clean high-energy surfaces are required. Reported here is the synthesis of single-crystalline MgO(111) nanosheets by a two-step process involving the formation of ultrathin Mg(OH)2 nanosheets as a precursor, and their selective topotactic conversion upon heating under dynamic vacuum. The defect-rich surface displays terminal -OH groups, three-coordinated O2- sites and low-coordinated Mg2+ sites, as well as single electrons trapped at oxygen vacancies, which render the MgO nanosheets highly reactive, as evidenced by the activation of CO molecules at low temperatures and pressures with formation of strongly adsorbed red-shifted CO and coupling of CO molecules into C2 species.
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Affiliation(s)
- Pengxin Liu
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, 8093, Zürich, Switzerland
| | - Paula Macarena Abdala
- Department of Mechanical and Process Engineering, ETH Zürich, Leonhardstrasse 21, 8092, Zürich, Switzerland
| | - Guillaume Goubert
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, 8093, Zürich, Switzerland
| | - Marc-Georg Willinger
- The Scientific Center for Optical and Electron Microscopy (ScopeM), ETH Zürich, John-von-Neumann-Weg 9, 8093, Zürich, Switzerland
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1-5, 8093, Zürich, Switzerland
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12
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Rekhtina M, Dal Pozzo A, Stoian D, Armutlulu A, Donat F, Blanco MV, Wang ZJ, Willinger MG, Fedorov A, Abdala PM, Müller CR. Effect of molten sodium nitrate on the decomposition pathways of hydrated magnesium hydroxycarbonate to magnesium oxide probed by in situ total scattering. Nanoscale 2020; 12:16462-16473. [PMID: 32478776 DOI: 10.1039/d0nr01760d] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The effect of NaNO3 and its physical state on the thermal decomposition pathways of hydrated magnesium hydroxycarbonate (hydromagnesite, HM) towards MgO was examined by in situ total scattering. Pair distribution function (PDF) analysis of these data allowed us to probe the structural evolution of pristine and NaNO3-promoted HM. A multivariate curve resolution alternating least squares (MCR-ALS) analysis identified the intermediate phases and their evolution upon the decomposition of both precursors to MgO. The total scattering results are discussed in relation with thermogravimetric measurements coupled with off-gas analysis. MgO is obtained from pristine HM (N2, 10 °C min-1) through an amorphous magnesium carbonate intermediate (AMC), formed after the partial removal of water of crystallization from HM. The decomposition continues via a gradual release of water (due to dehydration and dehydroxylation) and, in the last step, via decarbonation, leading to crystalline MgO. The presence of molten NaNO3 alters the decomposition pathways of HM, proceeding now through AMC and crystalline MgCO3. These results demonstrate that molten NaNO3 facilitates the release of water (from both water of crystallization and through dehydroxylation) and decarbonation, and promotes the crystallization of MgCO3 and MgO in comparison to pristine HM. MgO formed from the pristine HM precursor shows a smaller average crystallite size than NaNO3-promoted HM and preserves the initial nano-plate-like morphology of HM. NaNO3-promoted HM was decomposed to MgO that is characterized by a larger average crystallite size and irregular morphology. Additionally, in situ SEM allowed visualization of the morphological evolution of HM promoted with NaNO3 at a micrometre scale.
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Affiliation(s)
- Margarita Rekhtina
- Laboratory of Energy Science and Engineering, Department of Mechanical and Process Engineering, ETH Zürich, Leonhardstrasse 21, 8092 Zürich, Switzerland.
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13
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Niu Y, Huang X, Wang Y, Xu M, Chen J, Xu S, Willinger MG, Zhang W, Wei M, Zhang B. Manipulating interstitial carbon atoms in the nickel octahedral site for highly efficient hydrogenation of alkyne. Nat Commun 2020; 11:3324. [PMID: 32620829 PMCID: PMC7335178 DOI: 10.1038/s41467-020-17188-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 06/12/2020] [Indexed: 11/09/2022] Open
Abstract
Light elements in the interstitial site of transition metals have strong influence on heterogeneous catalysis via either expression of surface structures or even direct participation into reaction. Interstitial atoms are generally metastable with a strong environmental dependence, setting up giant challenges in controlling of heterogeneous catalysis. Herein, we show that the desired carbon atoms can be manipulated within nickel (Ni) lattice for improving the selectivity in acetylene hydrogenation reaction. The radius of octahedral space of Ni is expanded from 0.517 to 0.524 Å via formation of Ni3Zn, affording the dissociated carbon atoms to readily dissolve and diffuse at mild temperatures. Such incorporated carbon atoms coordinate with the surrounding Ni atoms for generation of Ni3ZnC0.7 and thereof inhibit the formation of subsurface hydrogen structures. Thus, the selectivity and stability are dramatically improved, as it enables suppressing the pathway of ethylene hydrogenation and restraining the accumulation of carbonaceous species on surface.
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Affiliation(s)
- Yiming Niu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 110016, Shenyang, China.,Department of Materials Science and Engineering, University of Science and Technology of China, 230026, Hefei, China
| | - Xing Huang
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, 14195, Berlin, Germany.,Scientific Center for Optical and Electron Microscopy, Otto-Stern-Weg 3, ETH Zurich, 8093, Zurich, Switzerland
| | - Yongzhao Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 110016, Shenyang, China.,Department of Materials Science and Engineering, University of Science and Technology of China, 230026, Hefei, China
| | - Ming Xu
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 100029, Beijing, China
| | - Junnan Chen
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 110016, Shenyang, China.,Department of Materials Science and Engineering, University of Science and Technology of China, 230026, Hefei, China
| | - Shuliang Xu
- Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023, Dalian, China
| | - Marc-Georg Willinger
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, 14195, Berlin, Germany.,Scientific Center for Optical and Electron Microscopy, Otto-Stern-Weg 3, ETH Zurich, 8093, Zurich, Switzerland
| | - Wei Zhang
- Electron Microscopy Center, Key Laboratory of Automobile Materials MOE, and School of Materials Science & Engineering, Jilin University, 130012, Changchun, China.
| | - Min Wei
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 100029, Beijing, China.
| | - Bingsen Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 110016, Shenyang, China. .,Department of Materials Science and Engineering, University of Science and Technology of China, 230026, Hefei, China.
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14
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Huang M, Bakharev PV, Wang ZJ, Biswal M, Yang Z, Jin S, Wang B, Park HJ, Li Y, Qu D, Kwon Y, Chen X, Lee SH, Willinger MG, Yoo WJ, Lee Z, Ruoff RS. Large-area single-crystal AB-bilayer and ABA-trilayer graphene grown on a Cu/Ni(111) foil. Nat Nanotechnol 2020; 15:289-295. [PMID: 31959931 DOI: 10.1038/s41565-019-0622-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 12/10/2019] [Indexed: 06/10/2023]
Abstract
High-quality AB-stacked bilayer or multilayer graphene larger than a centimetre has not been reported. Here, we report the fabrication and use of single-crystal Cu/Ni(111) alloy foils with controllable concentrations of Ni for the growth of large-area, high-quality AB-stacked bilayer and ABA-stacked trilayer graphene films by chemical vapour deposition. The stacking order, coverage and uniformity of the graphene films were evaluated by Raman spectroscopy and transmission electron microscopy including selected area electron diffraction and atomic resolution imaging. Electrical transport (carrier mobility and band-gap tunability) and thermal conductivity (the bilayer graphene has a thermal conductivity value of about 2,300 W m-1 K-1) measurements indicated the superior quality of the films. The tensile loading response of centimetre-scale bilayer graphene films supported by a 260-nm thick polycarbonate film was measured and the average values of the Young's modulus (478 GPa) and fracture strength (3.31 GPa) were obtained.
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Affiliation(s)
- Ming Huang
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Pavel V Bakharev
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea
| | - Zhu-Jun Wang
- Scientific Center for Optical and Electron Microscopy, ETH Zürich, Zürich, Switzerland
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin-Dahlem, Germany
| | - Mandakini Biswal
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea
| | - Zheng Yang
- SKKU Advanced Institute of Nano-Technology, Department of Nano Science and Technology, Sungkyunkwan University, Suwon, Republic of Korea
| | - Sunghwan Jin
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea
| | - Bin Wang
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea
| | - Hyo Ju Park
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Yunqing Li
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Deshun Qu
- SKKU Advanced Institute of Nano-Technology, Department of Nano Science and Technology, Sungkyunkwan University, Suwon, Republic of Korea
| | - Youngwoo Kwon
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea
| | - Xianjue Chen
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea
| | - Sun Hwa Lee
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea
| | - Marc-Georg Willinger
- Scientific Center for Optical and Electron Microscopy, ETH Zürich, Zürich, Switzerland
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin-Dahlem, Germany
| | - Won Jong Yoo
- SKKU Advanced Institute of Nano-Technology, Department of Nano Science and Technology, Sungkyunkwan University, Suwon, Republic of Korea
| | - Zonghoon Lee
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Rodney S Ruoff
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, Republic of Korea.
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea.
- Department of Chemistry, UNIST, Ulsan, Republic of Korea.
- School of Energy and Chemical Engineering, UNIST, Ulsan, Republic of Korea.
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15
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Wang ZJ, Dong J, Li L, Dong G, Cui Y, Yang Y, Wei W, Blume R, Li Q, Wang L, Xu X, Liu K, Barroo C, Frenken JWM, Fu Q, Bao X, Schlögl R, Ding F, Willinger MG. The Coalescence Behavior of Two-Dimensional Materials Revealed by Multiscale In Situ Imaging during Chemical Vapor Deposition Growth. ACS Nano 2020; 14:1902-1918. [PMID: 32031780 DOI: 10.1021/acsnano.9b08221] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Wafer-scale monocrystalline two-dimensional (2D) materials can theoretically be grown by seamless coalescence of individual domains into a large single crystal. Here we present a concise study of the coalescence behavior of crystalline 2D films using a combination of complementary in situ methods. Direct observation of overlayer growth from the atomic to the millimeter scale and under model- and industrially relevant growth conditions reveals the influence of the film-substrate interaction on the crystallinity of the 2D film. In the case of weakly interacting substrates, the coalescence behavior is dictated by the inherent growth kinetics of the 2D film. It is shown that the merging of coaligned domains leads to a distinct modification of the growth dynamics through the formation of fast-growing high-energy edges. The latter can be traced down to a reduced kink-creation energy at the interface between well-aligned domains. In the case of strongly interacting substrates, the lattice mismatch between film and substrate induces a pronounced moiré corrugation that determines the growth and coalescence behavior. It furthermore imposes additional criteria for seamless coalescence and determines the structure of grain boundaries. The experimental findings, obtained here for the case of graphene, are confirmed by theory-based growth simulations and can be generalized to other 2D materials that show 3- or 6-fold symmetry. Based on the gained understanding of the relation between film-substrate interaction, shape evolution, and coalescence behavior, conditions for seamless coalescence and, thus, for the optimization of large-scale production of monocrystalline 2D materials are established.
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Affiliation(s)
- Zhu-Jun Wang
- Scientific Center for Optical and Electron Microscopy, ETH Zürich , 8093 Zürich , Switzerland
- Department of Inorganic Chemistry , Fritz Haber Institute of the Max Planck Society , Berlin-Dahlem D-14195 , Germany
| | - Jichen Dong
- School of Materials Science and Engineering and Department of Chemistry , Ulsan National Institute of Science and Technology (UNIST) , Ulsan 44919 , Republic of Korea
| | - Linfei Li
- Department of Chemistry , University of Illinois at Chicago , Chicago , Illinois 60607 , United States
| | - Guocai Dong
- Kamerlingh Onnes Laboratory , Leiden University , P.O. Box 9504, 2300 RA Leiden , The Netherlands
| | - Yi Cui
- Vacuum Interconnected Nanotech Workstation , Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences , Suzhou 215123 , China
| | - Yang Yang
- State Key Laboratory of Catalysis , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , China
| | - Wei Wei
- Vacuum Interconnected Nanotech Workstation , Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences , Suzhou 215123 , China
- State Key Laboratory of Catalysis , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , China
| | - Raoul Blume
- Department of Inorganic Chemistry , Fritz Haber Institute of the Max Planck Society , Berlin-Dahlem D-14195 , Germany
| | - Qing Li
- Institute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology , Soochow University , Suzhou 215123 , Jiangsu , China
| | - Li Wang
- State Key Laboratory for Mesoscopic Physics, Collaborative Innovation Centre of Quantum Matter, School of Physics , Peking University , Beijing 100871 , China
| | - Xiaozhi Xu
- State Key Laboratory for Mesoscopic Physics, Collaborative Innovation Centre of Quantum Matter, School of Physics , Peking University , Beijing 100871 , China
| | - Kaihui Liu
- State Key Laboratory for Mesoscopic Physics, Collaborative Innovation Centre of Quantum Matter, School of Physics , Peking University , Beijing 100871 , China
| | - Cédric Barroo
- Chemical Physics of Materials and Catalysis, Faculty of Sciences , Université Libre de Bruxelles , CP243, 1050 Brussels , Belgium
| | - Joost W M Frenken
- Kamerlingh Onnes Laboratory , Leiden University , P.O. Box 9504, 2300 RA Leiden , The Netherlands
| | - Qiang Fu
- State Key Laboratory of Catalysis , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , China
| | - Xinhe Bao
- State Key Laboratory of Catalysis , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , China
| | - Robert Schlögl
- Department of Inorganic Chemistry , Fritz Haber Institute of the Max Planck Society , Berlin-Dahlem D-14195 , Germany
| | - Feng Ding
- School of Materials Science and Engineering and Department of Chemistry , Ulsan National Institute of Science and Technology (UNIST) , Ulsan 44919 , Republic of Korea
| | - Marc-Georg Willinger
- Scientific Center for Optical and Electron Microscopy, ETH Zürich , 8093 Zürich , Switzerland
- Department of Inorganic Chemistry , Fritz Haber Institute of the Max Planck Society , Berlin-Dahlem D-14195 , Germany
- Department of Colloid Chemistry , Max Planck Institute of Colloids and Interfaces , Potsdam D-14424 , Germany
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16
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Stephens KJ, Zichittella G, Saadun AJ, Büchele S, Puértolas B, Verel R, Krumeich F, Willinger MG, Pérez-Ramírez J. Transformation of titanium carbide into mesoporous titania for catalysed HBr oxidation. Catal Sci Technol 2020. [DOI: 10.1039/d0cy00805b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
TiC oxidises via a combination of spot-oxidation and shrinking core mechanisms, resulting in a mesoporous, high-performance TiO2–TiC composite for bromine production via catalysed HBr oxidation.
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Affiliation(s)
- Kyle J. Stephens
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Guido Zichittella
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Ali J. Saadun
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Simon Büchele
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Begoña Puértolas
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - René Verel
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Frank Krumeich
- Laboratory of Inorganic Chemistry
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Marc-Georg Willinger
- Scientific Center for Optical and Electron Microscopy
- ETH Zurich
- 8093 Zurich
- Switzerland
| | - Javier Pérez-Ramírez
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- 8093 Zurich
- Switzerland
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17
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Barroo C, Wang ZJ, Schlögl R, Willinger MG. Imaging the dynamics of catalysed surface reactions by in situ scanning electron microscopy. Nat Catal 2019. [DOI: 10.1038/s41929-019-0395-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Huang X, Farra R, Schlögl R, Willinger MG. Growth and Termination Dynamics of Multiwalled Carbon Nanotubes at Near Ambient Pressure: An in Situ Transmission Electron Microscopy Study. Nano Lett 2019; 19:5380-5387. [PMID: 31369275 PMCID: PMC6748788 DOI: 10.1021/acs.nanolett.9b01888] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/15/2019] [Indexed: 05/27/2023]
Abstract
Understanding the growth mechanism of carbon nanotubes (CNTs) has been long pursued since its discovery. With recent integration of in situ techniques into the study of CNT growth, important insights about the growth mechanism of CNT have been generated, which have improved our understanding significantly. However, previous in situ experiments were mainly conducted at low pressures which were far from the practical conditions. Direct information about the growth dynamics under relevant conditions is still absent and thus is highly desirable. In this work, we report atomic-scale observations of multiwalled CNT (MWCNT) growth and termination at near ambient pressure by in situ transmission electron microscopy. On the basis of the real-time imaging, we are able to reveal that the working catalyst is constantly reshaping at its apex during catalyzing CNT growth, whereas at the base the catalyst remains faceted and barely shows any morphological change. The active catalyst is identified as crystalline Fe3C, based on lattice fringes that can be imaged during growth. However, the oscillatory growth behavior of the CNT and the structural dynamics of the apex area strongly indicate that the carbon concentration in the catalyst particle is fluctuating during the course of CNT growth. Extended observations further reveal that the catalyst splitting can occur: whereas the majority of the catalyst stays at the base and continues catalyzing CNT growth, a small portion of it gets trapped inside of the growing nanotube. The catalyst splitting can take place multiple times, leading to shrinkage of both, catalyst size and diameter of CNT, and finally the growth termination of CNT due to the full coverage of the catalyst by carbon layers. Additionally, in situ observations show two more scenarios for the growth termination, that is, out-migration of the catalyst from the growing nanotube induced by (i) Oswald ripening and (ii) weakened adhesion strength between the catalyst and CNT.
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Affiliation(s)
- Xing Huang
- Fritz
Haber Institute of Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
- Scientific
Center for Optical and Electron Microscopy, ETH Zurich, Otto-Stern-Weg
3, 8093 Zurich, Switzerland
| | - Ramzi Farra
- Fritz
Haber Institute of Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Robert Schlögl
- Fritz
Haber Institute of Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
- Department
of Heterogeneous Reactions, Max Planck Institute
for Chemical Energy Conversion, 45470 Mülheim an der Ruhr, Germany
| | - Marc-Georg Willinger
- Fritz
Haber Institute of Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
- Scientific
Center for Optical and Electron Microscopy, ETH Zurich, Otto-Stern-Weg
3, 8093 Zurich, Switzerland
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19
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Tsoukalou A, Abdala PM, Stoian D, Huang X, Willinger MG, Fedorov A, Müller CR. Structural Evolution and Dynamics of an In2O3 Catalyst for CO2 Hydrogenation to Methanol: An Operando XAS-XRD and In Situ TEM Study. J Am Chem Soc 2019; 141:13497-13505. [DOI: 10.1021/jacs.9b04873] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Athanasia Tsoukalou
- Department of Mechanical and Process Engineering, ETH Zürich, Zürich CH 8092, Switzerland
| | - Paula M. Abdala
- Department of Mechanical and Process Engineering, ETH Zürich, Zürich CH 8092, Switzerland
| | - Dragos Stoian
- The Swiss-Norwegian Beamlines (SNBL) at ESRF, BP 220, Grenoble 38043, France
| | - Xing Huang
- Scientific Center for Optical and Electron Microscopy, ETH Zürich, Zürich CH 8093, Switzerland
| | - Marc-Georg Willinger
- Scientific Center for Optical and Electron Microscopy, ETH Zürich, Zürich CH 8093, Switzerland
| | - Alexey Fedorov
- Department of Mechanical and Process Engineering, ETH Zürich, Zürich CH 8092, Switzerland
| | - Christoph R. Müller
- Department of Mechanical and Process Engineering, ETH Zürich, Zürich CH 8092, Switzerland
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20
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Huang X, Teschner D, Dimitrakopoulou M, Fedorov A, Frank B, Kraehnert R, Rosowski F, Kaiser H, Schunk S, Kuretschka C, Schlögl R, Willinger MG, Trunschke A. Atomic-Scale Observation of the Metal-Promoter Interaction in Rh-Based Syngas-Upgrading Catalysts. Angew Chem Int Ed Engl 2019; 58:8709-8713. [PMID: 31066962 DOI: 10.1002/anie.201902750] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Indexed: 11/05/2022]
Abstract
The direct conversion of syngas to ethanol, typically using promoted Rh catalysts, is a cornerstone reaction in CO2 utilization and hydrogen storage technologies. A rational catalyst development requires a detailed structural understanding of the activated catalyst and the role of promoters in driving chemoselectivity. Herein, we report a comprehensive atomic-scale study of metal-promoter interactions in silica-supported Rh, Rh-Mn, and Rh-Mn-Fe catalysts by aberration-corrected (AC) TEM. While the catalytic reaction leads to the formation of a Rh carbide phase in the Rh-Mn/SiO2 catalyst, the addition of Fe results in the formation of bimetallic Rh-Fe alloys, which further improves the selectivity and prevents the carbide formation. In all promoted catalysts, Mn is present as an oxide decorating the metal particles. Based on the atomic insight obtained, structural and electronic modifications induced by promoters are revealed and a basis for refined theoretical models is provided.
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Affiliation(s)
- Xing Huang
- Department Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.,Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Detre Teschner
- Department Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.,Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Maria Dimitrakopoulou
- Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Alexey Fedorov
- Department of Mechanical and Process Engineering, ETH Zürich, Leonhardstrasse 21, 8092, Zürich, Switzerland
| | - Benjamin Frank
- BasCat-UniCat BASF Joint Lab, Hardenbergstraße 36, 10623, Berlin, Germany
| | - Ralph Kraehnert
- BasCat-UniCat BASF Joint Lab, Hardenbergstraße 36, 10623, Berlin, Germany
| | - Frank Rosowski
- BasCat-UniCat BASF Joint Lab, Hardenbergstraße 36, 10623, Berlin, Germany.,BASF SE, Process Research and Chemical Engineering, Heterogeneous Catalysis, Carl-Bosch-Straße 38, 67056, Ludwigshafen, Germany
| | - Harry Kaiser
- hte GmbH, Kurpfalzring 104, 69123, Heidelberg, Germany
| | | | - Christiane Kuretschka
- BASF SE, Process Research and Chemical Engineering, Heterogeneous Catalysis, Carl-Bosch-Straße 38, 67056, Ludwigshafen, Germany
| | - Robert Schlögl
- Department Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.,Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Marc-Georg Willinger
- Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Annette Trunschke
- Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
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21
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Böckmann H, Müller M, Hammud A, Willinger MG, Pszona M, Waluk J, Wolf M, Kumagai T. Near-Field Spectral Response of Optically Excited Scanning Tunneling Microscope Junctions Probed by Single-Molecule Action Spectroscopy. J Phys Chem Lett 2019; 10:2068-2074. [PMID: 30964304 PMCID: PMC6727595 DOI: 10.1021/acs.jpclett.9b00822] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The near-field spectral response of metallic nanocavities is a key characteristic in plasmon-assisted photophysical and photochemical processes. Here, we show that the near-field spectral response of an optically excited plasmonic scanning tunneling microscope (STM) junction can be probed by single-molecule reactions that serve as a nanoscale sensor detecting the local field intensity. Near-field action spectroscopy for the cis ↔ cis tautomerization of porphycene on a Cu(110) surface reveals that the field enhancement in the STM junction largely depends on microscopic structures not only on the tip apex, but also on its shaft. Using nanofabrication of Au tips with focused ion beam, we show that the spectral response is strongly modulated through the interference between the localized surface plasmon in the junction and propagating surface plasmon polariton generated on the shaft. Furthermore, it is demonstrated that the near-field spectral response can be manipulated by precisely shaping the tip shaft.
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Affiliation(s)
- Hannes Böckmann
- Department of Physical Chemistry and Department of Inorganic Chemistry, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Melanie Müller
- Department of Physical Chemistry and Department of Inorganic Chemistry, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Adnan Hammud
- Department of Physical Chemistry and Department of Inorganic Chemistry, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Marc-Georg Willinger
- Department of Physical Chemistry and Department of Inorganic Chemistry, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Maria Pszona
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw 01-224, Poland
| | - Jacek Waluk
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw 01-224, Poland
- Faculty
of Mathematics and Natural Sciences, College of Science, Cardinal Stefan Wyszyński University, Dewajtis 5, 01-815 Warsaw, Poland
| | - Martin Wolf
- Department of Physical Chemistry and Department of Inorganic Chemistry, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Takashi Kumagai
- Department of Physical Chemistry and Department of Inorganic Chemistry, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
- JST-PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
- E-mail:
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22
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Pereira MM, Gomes ES, Silva AV, Pinar AB, Willinger MG, Shanmugam S, Chizallet C, Laugel G, Losch P, Louis B. Biomass-mediated ZSM-5 zeolite synthesis: when self-assembly allows to cross the Si/Al lower limit. Chem Sci 2018; 9:6532-6539. [PMID: 30310584 PMCID: PMC6115686 DOI: 10.1039/c8sc01675e] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/04/2018] [Indexed: 11/21/2022] Open
Abstract
A family of Al-rich ZSM-5 zeolites with Si/Al = 8 ± 0.5 was prepared according to a biomass-mediated supramolecular approach. A combination of advanced characterisation techniques and periodic density functional theory (DFT) calculations unraveled the purity and stability of un-expected Al-enriched ZSM-5 structures, hence allowing to cross the frontier of Si/Al lower limit. In addition, these Al-rich ZSM-5 zeolites demonstrated high catalytic activity in n-hexane cracking and methanol conversion into hydrocarbons, being in line with the presence of numerous Brønsted acid sites.
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Affiliation(s)
- Marcelo Maciel Pereira
- Universidade Federal do Rio de Janeiro , Centro de Tecnologia , Departamento de Química Inorgânica , Avenida Athos da Silveira Ramos , 149, Ilha do Fundão , 21941-909 , Rio de Janeiro , RJ , Brazil
| | - Elisa Silva Gomes
- Universidade Federal do Rio de Janeiro , Centro de Tecnologia , Departamento de Química Inorgânica , Avenida Athos da Silveira Ramos , 149, Ilha do Fundão , 21941-909 , Rio de Janeiro , RJ , Brazil
| | - Alessandra Vieira Silva
- Universidade Federal do Rio de Janeiro , Centro de Tecnologia , Departamento de Química Inorgânica , Avenida Athos da Silveira Ramos , 149, Ilha do Fundão , 21941-909 , Rio de Janeiro , RJ , Brazil
| | - Ana Belen Pinar
- Laboratory for Catalysis and Sustainable Chemistry , ETH Zürich , Paul Scherrer Institute , CH-5232 Villigen , Switzerland
| | - Marc-Georg Willinger
- Department of Inorganic Chemistry , Fritz Haber Institute of the Max Planck Society , Faradayweg 4-6 , Berlin 14195 , Germany
| | - Sangaraju Shanmugam
- Department of Energy Systems and Engineering , Daegu Gyeongbuk Institute of Science and Technology (DGIST) , 50-1 Sang-Ri , Hyeongpung-Myeon, Dalseong-gun , Daegu , 711-873 , Republic of Korea
| | - Céline Chizallet
- IFP Energies Nouvelles , Ront-point de l'échangeur de Solaize , BP3, 69360 Solaize , France
| | - Guillaume Laugel
- Sorbonne Université , CNRS , Laboratoire de Réactivité de Surface (LRS) , F-75005 Paris , France
| | - Pit Losch
- Université de Strasbourg , CNRS , ICPEES , UMR 7515 , 67000 Strasbourg , France .
| | - Benoît Louis
- Université de Strasbourg , CNRS , ICPEES , UMR 7515 , 67000 Strasbourg , France .
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23
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Huang X, Liu Z, Millet MM, Dong J, Plodine M, Ding F, Schlögl R, Willinger MG. In Situ Atomic-Scale Observation of Surface-Tension-Induced Structural Transformation of Ag-NiP x Core-Shell Nanocrystals. ACS Nano 2018; 12:7197-7205. [PMID: 29924929 DOI: 10.1021/acsnano.8b03106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The properties of nanocrystals are highly dependent on their morphology, composition, and structure. Tailored synthesis over these parameters is successfully applied for the production of nanocrystals with desired properties for specific applications. However, in order to obtain full control over the properties, the behavior of nanocrystals under external stimuli and application conditions needs to be understood. Herein, using Ag-NiP x nanocrystals as a model system, we investigate the structural evolution upon thermal treatment by in situ aberration-corrected scanning transmission electron microscopy. A combination of real-time imaging with elemental analysis enables the observation of the transformation from a Ag-NiP x core-shell configuration to a Janus structure at the atomic scale. The transformation occurs through dewetting and crystallization of the NiP x shell and is accompanied by surface segregation of Ag. Further temperature increase leads to a complete sublimation of Ag and formation of individual Ni12P5 nanocrystals. The transformation is rationalized by theoretical modeling based on density functional theory calculations. Our model suggests that the transformation is driven by changes of the surface energy of NiP x and the interfacial energy between NiP x and Ag. The direct observation of atomistic dynamics during thermal-treatment-induced structural modification will help to understand more complex transformations that are induced by aging over time or the interaction with a reactive gas phase in applications such as catalysis.
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Affiliation(s)
- Xing Huang
- Department of Heterogeneous Reactions , Max Planck Institute for Chemical Energy Conversion , 45470 Mülheim an der Ruhr , Germany
- Department of Inorganic Chemistry , Fritz Haber Institute of Max Planck Society , Faradayweg 4-6 , 14195 Berlin , Germany
| | - Zhongqiang Liu
- Department of Physics , Qufu Normal University , Qufu 273165 , P.R. China
- Center for Multidimensional Carbon Materials , Institute for Basic Science (IBS) , Ulsan 44919 , Republic of Korea
| | - Marie-Mathilde Millet
- Department of Inorganic Chemistry , Fritz Haber Institute of Max Planck Society , Faradayweg 4-6 , 14195 Berlin , Germany
| | - Jichen Dong
- Center for Multidimensional Carbon Materials , Institute for Basic Science (IBS) , Ulsan 44919 , Republic of Korea
| | - Milivoj Plodine
- Department of Inorganic Chemistry , Fritz Haber Institute of Max Planck Society , Faradayweg 4-6 , 14195 Berlin , Germany
- Division of Material Physics , Rudjer Boskovic Institute , Bijenicka 54 , 10000 Zagreb , Croatia
| | - Feng Ding
- Center for Multidimensional Carbon Materials , Institute for Basic Science (IBS) , Ulsan 44919 , Republic of Korea
- Department of Materials Science and Engineering , Ulsan National Institute of Science and Technology (UNIST) , Ulsan 44919 , Republic of Korea
| | - Robert Schlögl
- Department of Heterogeneous Reactions , Max Planck Institute for Chemical Energy Conversion , 45470 Mülheim an der Ruhr , Germany
- Department of Inorganic Chemistry , Fritz Haber Institute of Max Planck Society , Faradayweg 4-6 , 14195 Berlin , Germany
| | - Marc-Georg Willinger
- Department of Inorganic Chemistry , Fritz Haber Institute of Max Planck Society , Faradayweg 4-6 , 14195 Berlin , Germany
- Scientific Center for Optical and Electron Microscopy , ETH Zürich , Auguste-Piccard-Hof 1 , 8093 Zürich , Switzerland
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24
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Yi D, Luo D, Wang ZJ, Dong J, Zhang X, Willinger MG, Ruoff RS, Ding F. What Drives Metal-Surface Step Bunching in Graphene Chemical Vapor Deposition? Phys Rev Lett 2018; 120:246101. [PMID: 29956979 DOI: 10.1103/physrevlett.120.246101] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Indexed: 06/08/2023]
Abstract
Compressive strain relaxation of a chemical vapor deposition (CVD) grown graphene overlayer has been considered to be the main driving force behind metal surface step bunching (SB) in CVD graphene growth. Here, by combining theoretical studies with experimental observations, we prove that the SB can occur even in the absence of a compressive strain, is enabled by the rapid diffusion of metal adatoms beneath the graphene and is driven by the release of the bending energy of the graphene overlayer in the vicinity of steps. Based on this new understanding, we explain a number of experimental observations such as the temperature dependence of SB, and how SB depends on the thickness of the graphene film. This study also shows that SB is a general phenomenon that can occur in all substrates covered by films of two-dimensional (2D) materials.
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Affiliation(s)
- Ding Yi
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Da Luo
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Zhu-Jun Wang
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin-Dahlem D-14195, Germany
| | - Jichen Dong
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Xu Zhang
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Marc-Georg Willinger
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin-Dahlem D-14195, Germany
| | - Rodney S Ruoff
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Feng Ding
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
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25
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Huang X, Jones T, Fan H, Willinger MG. Real-time atomic scale observation of void formation and anisotropic growth in II-VI semiconducting ribbons. Nanoscale 2017; 9:12479-12485. [PMID: 28816305 DOI: 10.1039/c7nr02231j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Void formation in semiconductors is generally considered to be deteriorating. However, for some systems, void formation and evolution are beneficial and can be used for the fabrication of novel nanostructures. In either scenario, the understanding of void formation and evolution is of both scientific and technical high importance. Herein, using ZnS ribbons as an example, we report real-time observations of void formation and the kinetics of growth at the nano- and atomic scales upon heating. Direct imaging reveals that voids, created by a focused electron beam in wurtzite (WZ) ribbons, have a rectangular shape elongated along the <0001> direction. The voids are enclosed by low-surface-energy planes including {01-10} and {2-1-10}, with minor contribution from the higher-energy {0001} planes. Driven by thermodynamics to minimize surface energy, the voids grow straight along the [000±1] directions, exhibiting a strong anisotropy. Occasionally, we observe oscillatory kinetics involving periodic void growth and shrinkage, likely due to the fluctuation of the local chemical potential leading to a transitional kinetic state. We also reveal that the morphology and growth kinetics of voids are highly structure-dependent. Real-time observation during void growth through the complex WZ-zinc blende (ZB)-WZ structure shows that the void, with an initial elongated rectangular morphology in the WZ domain, transforms into a different shape, dominated by the {110} surfaces, after migrating to a domain of the ZB structure. However, when the void moves from the ZB to the WZ domain, it transforms back into a rectangular shape followed by fast growth along the [0001] direction. Our experimental results, together with density functional theory (DFT) calculations, provide valuable insights into the mechanistic understanding of void formation and evolution in semiconductors. More importantly, our study may shed light on new pathways for the morphological modulation of nanostructures by utilizing the intrinsic anisotropy of void evolution in WZ semiconductors.
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Affiliation(s)
- Xing Huang
- Department of Inorganic Chemistry, Fritz-Haber Institute of Max-Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.
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26
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Maurin-Pasturel G, Long J, Palacios MA, Guérin C, Charnay C, Willinger MG, Trifonov AA, Larionova J, Guari Y. Inside Cover: Engineered Au Core@Prussian Blue Analogous Shell Nanoheterostructures: Their Magnetic and Optical Properties (Chem. Eur. J. 31/2017). Chemistry 2017. [DOI: 10.1002/chem.201701180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Guillaume Maurin-Pasturel
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Jérôme Long
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Maria A. Palacios
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Christian Guérin
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Clarence Charnay
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Marc-Georg Willinger
- Fritz Haber Institute of the Max Planck Society; Department of Inorganic Chemistry; Faradayweg 4-6 14195 Berlin Germany
| | - Alexander A. Trifonov
- Institute of Organometallic Chemistry of Russian Academy of Sciences; Tropinina 49, GSO-445 630950 Nizhny Novgorod Russia
| | - Joulia Larionova
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Yannick Guari
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
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27
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Maurin-Pasturel G, Long J, Palacios MA, Guérin C, Charnay C, Willinger MG, Trifonov AA, Larionova J, Guari Y. Engineered Au Core@Prussian Blue Analogous Shell Nanoheterostructures: Their Magnetic and Optical Properties. Chemistry 2017; 23:7483-7496. [DOI: 10.1002/chem.201605903] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Guillaume Maurin-Pasturel
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Jérôme Long
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Maria A. Palacios
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Christian Guérin
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Clarence Charnay
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Marc-Georg Willinger
- Fritz Haber Institute of the Max Planck Society; Department of Inorganic Chemistry; Faradayweg 4-6 14195 Berlin Germany
| | - Alexander A. Trifonov
- Institute of Organometallic Chemistry of Russian Academy of Sciences; Tropinina 49, GSO-445 630950 Nizhny Novgorod Russia
| | - Joulia Larionova
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
| | - Yannick Guari
- ICGM (UMR5253), Univ. Montpellier, CNRS, ENSCM; Université de Montpellier, Site Triolet; Place E. Bataillon 34095 Montpellier Cedex 5 France
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28
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Pavlopoulos NG, Dubose JT, Liu Y, Huang X, Pinna N, Willinger MG, Lian T, Char K, Pyun J. Type I vs. quasi-type II modulation in CdSe@CdS tetrapods: ramifications for noble metal tipping. CrystEngComm 2017. [DOI: 10.1039/c7ce01558e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report on noble metal tipping of heterostructured nanocrystals (NCs) of CdSe@CdS tetrapods (TPs) as a chemical reaction to manifest energetic differences between type I and quasi-type II heterojunctions.
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Affiliation(s)
| | - Jeffrey T. Dubose
- Department of Chemistry and Biochemistry
- University of Arizona
- Tucson
- USA
| | - Yawei Liu
- Department of Chemistry
- Emory University
- Atlanta
- USA
| | - Xing Huang
- Institut fur Chemie
- Humboldt-Universitat zu Berlin
- 12489 Berlin
- Germany
| | - Nicola Pinna
- Department of Inorganic Chemistry
- Fritz Haber Institute of the Max Planck Society
- Berlin
- Germany
| | | | | | - Kookheon Char
- World Class University Program for Chemical Convergence for Energy and Environment
- School of Chemical and Biological Engineering
- Seoul National University
- Seoul 151-744
- Korea
| | - Jeffrey Pyun
- Department of Chemistry and Biochemistry
- University of Arizona
- Tucson
- USA
- World Class University Program for Chemical Convergence for Energy and Environment
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29
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Wang ZJ, Dong J, Cui Y, Eres G, Timpe O, Fu Q, Ding F, Schloegl R, Willinger MG. Stacking sequence and interlayer coupling in few-layer graphene revealed by in situ imaging. Nat Commun 2016; 7:13256. [PMID: 27759024 PMCID: PMC5075831 DOI: 10.1038/ncomms13256] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 09/13/2016] [Indexed: 11/11/2022] Open
Abstract
In the transition from graphene to graphite, the addition of each individual graphene layer modifies the electronic structure and produces a different material with unique properties. Controlled growth of few-layer graphene is therefore of fundamental interest and will provide access to materials with engineered electronic structure. Here we combine isothermal growth and etching experiments with in situ scanning electron microscopy to reveal the stacking sequence and interlayer coupling strength in few-layer graphene. The observed layer-dependent etching rates reveal the relative strength of the graphene-graphene and graphene-substrate interaction and the resulting mode of adlayer growth. Scanning tunnelling microscopy and density functional theory calculations confirm a strong coupling between graphene edge atoms and platinum. Simulated etching confirms that etching can be viewed as reversed growth. This work demonstrates that real-time imaging under controlled atmosphere is a powerful method for designing synthesis protocols for sp2 carbon nanostructures in between graphene and graphite.
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Affiliation(s)
- Zhu-Jun Wang
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin-Dahlem D-14195, Germany
| | - Jichen Dong
- Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Yi Cui
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Gyula Eres
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Olaf Timpe
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin-Dahlem D-14195, Germany
| | - Qiang Fu
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Feng Ding
- Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hong Kong 999077, China
| | - R. Schloegl
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin-Dahlem D-14195, Germany
| | - Marc-Georg Willinger
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin-Dahlem D-14195, Germany
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30
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Weatherup RS, Shahani AJ, Wang ZJ, Mingard K, Pollard AJ, Willinger MG, Schloegl R, Voorhees PW, Hofmann S. In Situ Graphene Growth Dynamics on Polycrystalline Catalyst Foils. Nano Lett 2016; 16:6196-6206. [PMID: 27576749 PMCID: PMC5064306 DOI: 10.1021/acs.nanolett.6b02459] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The dynamics of graphene growth on polycrystalline Pt foils during chemical vapor deposition (CVD) are investigated using in situ scanning electron microscopy and complementary structural characterization of the catalyst with electron backscatter diffraction. A general growth model is outlined that considers precursor dissociation, mass transport, and attachment to the edge of a growing domain. We thereby analyze graphene growth dynamics at different length scales and reveal that the rate-limiting step varies throughout the process and across different regions of the catalyst surface, including different facets of an individual graphene domain. The facets that define the domain shapes lie normal to slow growth directions, which are determined by the interfacial mobility when attachment to domain edges is rate-limiting, as well as anisotropy in surface diffusion as diffusion becomes rate-limiting. Our observations and analysis thus reveal that the structure of CVD graphene films is intimately linked to that of the underlying polycrystalline catalyst, with both interfacial mobility and diffusional anisotropy depending on the presence of step edges and grain boundaries. The growth model developed serves as a general framework for understanding and optimizing the growth of 2D materials on polycrystalline catalysts.
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Affiliation(s)
- Robert S. Weatherup
- Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom
- Materials Sciences Division, Lawrence Berkeley
National Laboratory, 1 Cyclotron Road, Berkeley California 94720, United States
- E-mail:
| | - Ashwin J. Shahani
- Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, Illinois 60208, United States
| | - Zhu-Jun Wang
- Fritz Haber Institute, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Ken Mingard
- National Physical
Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, United Kingdom
| | - Andrew J. Pollard
- National Physical
Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, United Kingdom
| | | | - Robert Schloegl
- Fritz Haber Institute, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Peter W. Voorhees
- Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, Illinois 60208, United States
| | - Stephan Hofmann
- Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom
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31
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Huang X, Yu Y, Jones T, Fan H, Wang L, Xia J, Wang ZJ, Shao LD, Meng XM, Willinger MG. In Situ Formation of Crystallographically Oriented Semiconductor Nanowire Arrays via Selective Vaporization for Optoelectronic Applications. Adv Mater 2016; 28:7603-7612. [PMID: 27373221 DOI: 10.1002/adma.201602867] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Indexed: 06/06/2023]
Abstract
Direct transformation of bulk crystals to single-crystalline crystallographically oriented semiconductor nanowire arrays is presented. Real-time imaging during in situ environmental scanning electron microscopy experiment clearly demonstrates that the nanowire arrays form through a selective vaporization process with respect to the crystallography of wurtzite crystals. Due to the high quality of the prepared semiconductor nanowire arrays, photodetectors constructed from them can present superior optoelectronic performances.
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Affiliation(s)
- Xing Huang
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, P. R. China.
- Fritz Haber Institute of Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.
| | - Yongqiang Yu
- School of Electronic Science and Applied Physics, Hefei University of Technology, Hefei, 230009, P. R. China
| | - Travis Jones
- Fritz Haber Institute of Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany
| | - Hua Fan
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, P. R. China
| | - Lei Wang
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, P. R. China
| | - Jing Xia
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, P. R. China
| | - Zhu-Jun Wang
- Fritz Haber Institute of Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany
| | - Li-Dong Shao
- Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, Shanghai University of Electric Power, 200090, Shanghai, P. R. China
| | - Xiang-Min Meng
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, P. R. China.
| | - Marc-Georg Willinger
- Fritz Haber Institute of Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.
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32
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Büchner C, Wang ZJ, Burson KM, Willinger MG, Heyde M, Schlögl R, Freund HJ. A Large-Area Transferable Wide Band Gap 2D Silicon Dioxide Layer. ACS Nano 2016; 10:7982-7989. [PMID: 27421042 DOI: 10.1021/acsnano.6b03929] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An atomically smooth silica bilayer is transferred from the growth substrate to a new support via mechanical exfoliation at millimeter scale. The atomic structure and morphology are maintained perfectly throughout the process. A simple heating treatment results in complete removal of the transfer medium. Low-energy electron diffraction, Auger electron spectroscopy, scanning tunneling microscopy, and environmental scanning electron microscopy show the success of the transfer steps. Excellent chemical and thermal stability result from the absence of dangling bonds in the film structure. By adding this wide band gap oxide to the toolbox of 2D materials, possibilities for van der Waals heterostructures will be broadened significantly.
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Affiliation(s)
- Christin Büchner
- Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6, 14195 Berlin, Germany
| | - Zhu-Jun Wang
- Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6, 14195 Berlin, Germany
| | - Kristen M Burson
- Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6, 14195 Berlin, Germany
| | - Marc-Georg Willinger
- Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6, 14195 Berlin, Germany
| | - Markus Heyde
- Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6, 14195 Berlin, Germany
| | - Robert Schlögl
- Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6, 14195 Berlin, Germany
| | - Hans-Joachim Freund
- Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6, 14195 Berlin, Germany
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33
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Willinger E, Yi Y, Tarasov A, Blume R, Massué C, Girgsdies F, Querner C, Schwab E, Schlögl R, Willinger MG. Atomic-Scale Insight on the Increased Stability of Tungsten-Modified Platinum/Carbon Fuel Cell Catalysts. ChemCatChem 2016. [DOI: 10.1002/cctc.201600068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Elena Willinger
- Department of Inorganic Chemistry; Fritz Haber Institute of the Max Planck Society; Faradayweg 4-6 14195 Berlin Germany
- Max Planck Institute for Chemical Energy Conversion; Stiftstrasse 34-36 45470 Mülheim an der Ruhr Germany
| | - Youngmi Yi
- Max Planck Institute for Chemical Energy Conversion; Stiftstrasse 34-36 45470 Mülheim an der Ruhr Germany
| | - Andrey Tarasov
- Department of Inorganic Chemistry; Fritz Haber Institute of the Max Planck Society; Faradayweg 4-6 14195 Berlin Germany
| | - Raoul Blume
- Max Planck Institute for Chemical Energy Conversion; Stiftstrasse 34-36 45470 Mülheim an der Ruhr Germany
| | - Cyriac Massué
- Max Planck Institute for Chemical Energy Conversion; Stiftstrasse 34-36 45470 Mülheim an der Ruhr Germany
| | - Frank Girgsdies
- Department of Inorganic Chemistry; Fritz Haber Institute of the Max Planck Society; Faradayweg 4-6 14195 Berlin Germany
| | | | | | - Robert Schlögl
- Department of Inorganic Chemistry; Fritz Haber Institute of the Max Planck Society; Faradayweg 4-6 14195 Berlin Germany
- Max Planck Institute for Chemical Energy Conversion; Stiftstrasse 34-36 45470 Mülheim an der Ruhr Germany
| | - Marc-Georg Willinger
- Department of Inorganic Chemistry; Fritz Haber Institute of the Max Planck Society; Faradayweg 4-6 14195 Berlin Germany
- Max Planck Institute for Chemical Energy Conversion; Stiftstrasse 34-36 45470 Mülheim an der Ruhr Germany
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34
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Beermann V, Gocyla M, Willinger E, Rudi S, Heggen M, Dunin-Borkowski RE, Willinger MG, Strasser P. Rh-Doped Pt-Ni Octahedral Nanoparticles: Understanding the Correlation between Elemental Distribution, Oxygen Reduction Reaction, and Shape Stability. Nano Lett 2016; 16:1719-1725. [PMID: 26854940 DOI: 10.1021/acs.nanolett.5b04636] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Thanks to their remarkably high activity toward oxygen reduction reaction (ORR), platinum-based octahedrally shaped nanoparticles have attracted ever increasing attention in last years. Although high activities for ORR catalysts have been attained, the practical use is still limited by their long-term stability. In this work, we present Rh-doped Pt-Ni octahedral nanoparticles with high activities up to 1.14 A mgPt(-1) combined with improved performance and shape stability compared to previous bimetallic Pt-Ni octahedral particles. The synthesis, the electrocatalytic performance of the particles toward ORR, and atomic degradation mechanisms are investigated with a major focus on a deeper understanding of strategies to stabilize morphological particle shape and consequently their performance. Rh surface-doped octahedral Pt-Ni particles were prepared at various Rh levels. At and above about 3 atom %, the nanoparticles maintained their octahedral shape even past 30,000 potential cycles, while undoped bimetallic reference nanoparticles show a complete loss in octahedral shape already after 8000 cycles in the same potential window. Detailed atomic insight in these observations is obtained from aberration-corrected scanning transmission electron microscopy (STEM) and energy dispersive X-ray (EDX) analysis. Our analysis shows that it is the migration of Pt surface atoms and not, as commonly thought, the dissolution of Ni that constitutes the primary origin of the octahedral shape loss for Pt-Ni nanoparticles. Using small amounts of Rh we were able to suppress the migration rate of platinum atoms and consequently suppress the octahedral shape loss of Pt-Ni nanoparticles.
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Affiliation(s)
- Vera Beermann
- Electrochemical Energy, Catalysis, and Material Science Laboratory, Department of Chemistry, Technical University Berlin , 10623 Berlin, Germany
| | - Martin Gocyla
- Ernst-Ruska Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich GmbH , 52425 Jülich, Germany
| | - Elena Willinger
- Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, 14195 Berlin, Germany
| | - Stefan Rudi
- Electrochemical Energy, Catalysis, and Material Science Laboratory, Department of Chemistry, Technical University Berlin , 10623 Berlin, Germany
| | - Marc Heggen
- Ernst-Ruska Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich GmbH , 52425 Jülich, Germany
| | - Rafal E Dunin-Borkowski
- Ernst-Ruska Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich GmbH , 52425 Jülich, Germany
| | - Marc-Georg Willinger
- Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, 14195 Berlin, Germany
| | - Peter Strasser
- Electrochemical Energy, Catalysis, and Material Science Laboratory, Department of Chemistry, Technical University Berlin , 10623 Berlin, Germany
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35
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Fechler N, Zussblatt NP, Rothe R, Schlögl R, Willinger MG, Chmelka BF, Antonietti M. Eutectic Syntheses of Graphitic Carbon with High Pyrazinic Nitrogen Content. Adv Mater 2016; 28:1287-1294. [PMID: 26178584 DOI: 10.1002/adma.201501503] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 06/08/2015] [Indexed: 06/04/2023]
Abstract
Mixtures of phenols/ketones and urea show eutectic behavior upon gentle heating. These mixtures possess liquid-crystalline-like phases that can be processed. The architecture of phenol/ketone acts as structure-donating motif, while urea serves as melting-point reduction agent. Condensation at elevated temperatures results in nitrogen-containing carbons with remarkably high nitrogen content of mainly pyrazinic nature.
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Affiliation(s)
- Nina Fechler
- Max Planck Institute of Colloids and Interfaces, Department of Colloid Chemistry, Research Campus Golm, 14424, Potsdam, Germany
| | - Niels P Zussblatt
- Department of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Regina Rothe
- Max Planck Institute of Colloids and Interfaces, Department of Colloid Chemistry, Research Campus Golm, 14424, Potsdam, Germany
| | - Robert Schlögl
- Fritz Haber Institute of the Max Planck Society, Department of Inorganic Chemistry, Faradayweg, 4-6, 14195, Berlin, Germany
| | - Marc-Georg Willinger
- Fritz Haber Institute of the Max Planck Society, Department of Inorganic Chemistry, Faradayweg, 4-6, 14195, Berlin, Germany
- Max Planck Institute for Chemical Energy Conversion, Department of Heterogeneous Reactions, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Bradley F Chmelka
- Department of Chemical Engineering, University of California at Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Markus Antonietti
- Max Planck Institute of Colloids and Interfaces, Department of Colloid Chemistry, Research Campus Golm, 14424, Potsdam, Germany
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36
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Zhang B, Niu Y, Xu J, Pan X, Chen CM, Shi W, Willinger MG, Schlögl R, Su DS. Tuning the surface structure of supported PtNixbimetallic electrocatalysts for the methanol electro-oxidation reaction. Chem Commun (Camb) 2016; 52:3927-30. [DOI: 10.1039/c5cc08978f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structural investigation of bimetallic PtNi2nanoparticles from polycrystalline to randomly mixed and core–shell structures induced by thermal annealing in different atmospheres.
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Affiliation(s)
- Bingsen Zhang
- Shenyang National Laboratory for Materials Science
- Institute of Metal Research
- Chinese Academy of Sciences
- Shenyang
- China
| | - Yiming Niu
- Shenyang National Laboratory for Materials Science
- Institute of Metal Research
- Chinese Academy of Sciences
- Shenyang
- China
| | - Junyuan Xu
- Shenyang National Laboratory for Materials Science
- Institute of Metal Research
- Chinese Academy of Sciences
- Shenyang
- China
| | - Xiaoli Pan
- Shenyang National Laboratory for Materials Science
- Institute of Metal Research
- Chinese Academy of Sciences
- Shenyang
- China
| | - Cheng-Meng Chen
- Key Laboratory of Carbon Materials
- Institute of Coal Chemistry
- Chinese Academy of Sciences
- Taiyuan
- China
| | - Wen Shi
- Shenyang National Laboratory for Materials Science
- Institute of Metal Research
- Chinese Academy of Sciences
- Shenyang
- China
| | | | - Robert Schlögl
- Fritz Haber Institute of the Max Planck Society
- Berlin
- Germany
| | - Dang Sheng Su
- Shenyang National Laboratory for Materials Science
- Institute of Metal Research
- Chinese Academy of Sciences
- Shenyang
- China
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37
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Pavlopoulos NG, Dubose JT, Pinna N, Willinger MG, Char K, Pyun J. Synthesis and Assembly of Dipolar Heterostructured Tetrapods: Colloidal Polymers with "Giant tert-butyl" Groups. Angew Chem Int Ed Engl 2015; 55:1787-91. [PMID: 26696128 DOI: 10.1002/anie.201510458] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Indexed: 11/08/2022]
Abstract
We report on the first synthesis of a heterostructured semiconductor tetrapod from CdSe@CdS that carries a single dipolar nanoparticle tip from a core-shell colloid of Au@Co. A four-step colloidal total synthesis was developed, where the key step in the synthesis was the selective deposition of a single AuNP tip onto a CdSe@CdS tetrapod under UV-irradiation. Synthetic accessibility to this dipolar heterostructured tetrapod enabled the use of these as colloidal monomers to form colloidal polymers that carry the semiconductor tetrapod as a side chain group attached to the CoNP colloidal polymer main chain. The current report details a number of novel discoveries on the selective synthesis of an asymmetric heterostructured tetrapod that is capable of 1D dipolar assembly into colloidal polymers that carry tetrapods as side chain groups that mimic "giant tert-butyl groups".
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Affiliation(s)
- Nicholas G Pavlopoulos
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd., Tucson, AZ, 85721, USA
| | - Jeffrey T Dubose
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd., Tucson, AZ, 85721, USA
| | - Nicola Pinna
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany
| | - Marc-Georg Willinger
- Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany
| | - Kookheon Char
- Department of Chemical and Biological Engineering, Program for Chemical Convergence for Energy & Environment & the Center for Intelligent Hybrids, Seoul National University, Seoul, 151-744, Korea.
| | - Jeffrey Pyun
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd., Tucson, AZ, 85721, USA. .,Department of Chemical and Biological Engineering, Program for Chemical Convergence for Energy & Environment & the Center for Intelligent Hybrids, Seoul National University, Seoul, 151-744, Korea.
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38
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Schwach P, Frandsen W, Willinger MG, Schlögl R, Trunschke A. Structure sensitivity of the oxidative activation of methane over MgO model catalysts: I. Kinetic study. J Catal 2015. [DOI: 10.1016/j.jcat.2015.05.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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39
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Busser GW, Mei B, Weide P, Vesborg PCK, Stührenberg K, Bauer M, Huang X, Willinger MG, Chorkendorff I, Schlögl R, Muhler M. Cocatalyst Designing: A Regenerable Molybdenum-Containing Ternary Cocatalyst System for Efficient Photocatalytic Water Splitting. ACS Catal 2015. [DOI: 10.1021/acscatal.5b01428] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- G. Wilma Busser
- Laboratory
of Industrial Chemistry, Ruhr-Universität Bochum, Universitätsstraße
150, 44780 Bochum, Germany
| | - Bastian Mei
- Department
of Physics, CINF, Technical University of Denmark, Fysikvej, 2800, Kongens Lyngby, Denmark
| | - Philipp Weide
- Laboratory
of Industrial Chemistry, Ruhr-Universität Bochum, Universitätsstraße
150, 44780 Bochum, Germany
| | - Peter C. K. Vesborg
- Department
of Physics, CINF, Technical University of Denmark, Fysikvej, 2800, Kongens Lyngby, Denmark
| | - Kai Stührenberg
- Fakultät
für Naturwissenschaften, Department Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Matthias Bauer
- Fakultät
für Naturwissenschaften, Department Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Xing Huang
- Anorganische
Chemie, Fritz-Haber-Institut, Faradayweg 4-6, 14195 Berlin, Germany
| | - Marc-Georg Willinger
- Anorganische
Chemie, Fritz-Haber-Institut, Faradayweg 4-6, 14195 Berlin, Germany
| | - Ib Chorkendorff
- Department
of Physics, CINF, Technical University of Denmark, Fysikvej, 2800, Kongens Lyngby, Denmark
| | - Robert Schlögl
- Anorganische
Chemie, Fritz-Haber-Institut, Faradayweg 4-6, 14195 Berlin, Germany
| | - Martin Muhler
- Laboratory
of Industrial Chemistry, Ruhr-Universität Bochum, Universitätsstraße
150, 44780 Bochum, Germany
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40
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Huang X, Yu YQ, Xia J, Fan H, Wang L, Willinger MG, Yang XP, Jiang Y, Zhang TR, Meng XM. Ultraviolet photodetectors with high photosensitivity based on type-II ZnS/SnO2 core/shell heterostructured ribbons. Nanoscale 2015; 7:5311-5319. [PMID: 25721309 DOI: 10.1039/c5nr00150a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Semiconducting heterostructures with type-II band structure have attracted much attention due to their novel physical properties and wide applications in optoelectronics. Herein, we report, for the first time, a controlled synthesis of type-II ZnS/SnO2 heterostructured ribbon composed of SnO2 nanoparticles that uniformly cover the surface of ZnS ribbon via a simple and versatile thermal evaporation approach. Structural analysis indicated that the majority of SnO2 nanoparticles have an equivalent zone axis, i.e., <-313> of rutile SnO2, which is perpendicular to ±(2-1-10) facets (top/down surfaces) of ZnS ribbon. For those SnO2 nanoparticles decorated on ±(01-10) facets (side surfaces) of ZnS ribbon, an epitaxial relationship of (01-10)ZnO//(020)SnO2 and [2-1-10]ZnO//[001]SnO2 was identified. To explore their electronic and optoelectronic properties, we constructed field-effect transistors from as-prepared new heterostructures, which exhibited an n-type characteristic with an on/off ratio of ∼10(3) and a fast carrier mobility of ∼33.2 cm2 V(-1) s(-1). Owing to the spatial separation of photogenerated electron-hole pairs from type-II band alignment together with the good contacts between electrodes and ribbon, the resultant photodetector showed excellent photoresponse properties, including large photocurrent, high sensitivity (external quantum efficiency as high as ∼2.4×10(7)%), good stability and reproducibility, and relatively fast response speed. Our results suggest great potential of ZnS/SnO2 heterostructures for efficient UV light sensing, and, more importantly, signify the advantages of type-II semiconducting heterostructures for construction of high-performance nano-photodetectors.
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Affiliation(s)
- Xing Huang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
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41
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Wang ZJ, Weinberg G, Zhang Q, Lunkenbein T, Klein-Hoffmann A, Kurnatowska M, Plodinec M, Li Q, Chi L, Schloegl R, Willinger MG. Direct observation of graphene growth and associated copper substrate dynamics by in situ scanning electron microscopy. ACS Nano 2015; 9:1506-19. [PMID: 25584770 DOI: 10.1021/nn5059826] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This work highlights the importance of in situ experiments for an improved understanding of graphene growth on copper via metal-catalyzed chemical vapor deposition (CVD). Graphene growth inside the chamber of a modified environmental scanning electron microscope under relevant low-pressure CVD conditions allows visualizing structural dynamics of the active catalyst simultaneously with graphene nucleation and growth in an unparalleled way. It enables the observation of a complete CVD process from substrate annealing through graphene nucleation and growth and, finally, substrate cooling in real time and nanometer-scale resolution without the need of sample transfer. A strong dependence of surface dynamics such as sublimation and surface premelting on grain orientation is demonstrated, and the influence of substrate dynamics on graphene nucleation and growth is presented. Insights on the growth mechanism are provided by a simultaneous observation of the growth front propagation and nucleation rate. Furthermore, the role of trace amounts of oxygen during growth is discussed and related to graphene-induced surface reconstructions during cooling. Above all, this work demonstrates the potential of the method for in situ studies of surface dynamics on active metal catalysts.
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Affiliation(s)
- Zhu-Jun Wang
- Fritz Haber Institute of the Max Planck Society , D-14195 Berlin-Dahlem, Germany
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42
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Ferreira dos Santos C, Gomes PS, Almeida MM, Willinger MG, Franke RP, Fernandes MH, Costa ME. Gold-dotted hydroxyapatite nanoparticles as multifunctional platforms for medical applications. RSC Adv 2015. [DOI: 10.1039/c5ra11978b] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Hydroxyapatite nanoparticles decorated with gold dots, synthesized by a citrate mediated chemical method, enhance the osteogenic differentiation of HMSC.
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Affiliation(s)
- Catarina Ferreira dos Santos
- Department of Mechanical Engineering
- Escola Superior de Tecnologia de Setúbal
- Instituto Politécnico de Setúbal
- Setúbal
- Portugal
| | - Pedro Sousa Gomes
- Laboratory for Bone Metabolism and Regeneration
- Faculdade de Medicina Dentária
- Universidade do Porto
- Portugal
- MedInUP – Center for Drug Discovery and Innovative Medicines
| | - Maria Margarida Almeida
- Department of Materials and Ceramics Engineering
- CICECO
- Aveiro Institute of Materials
- University of Aveiro
- 3810-193 Aveiro
| | | | - Ralf-Peter Franke
- Central Institute for Biomedical Technology
- Biomaterials Division
- University of Ulm
- Ulm
- Germany
| | - Maria Helena Fernandes
- Laboratory for Bone Metabolism and Regeneration
- Faculdade de Medicina Dentária
- Universidade do Porto
- Portugal
- MedInUP – Center for Drug Discovery and Innovative Medicines
| | - Maria Elisabete Costa
- Department of Materials and Ceramics Engineering
- CICECO
- Aveiro Institute of Materials
- University of Aveiro
- 3810-193 Aveiro
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43
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Willinger MG, Polleux J, Antonietti M, Cölfen H, Pinna N, Nassif N. Structural evolution of aragonite superstructures obtained in the presence of the siderophore deferoxamine. CrystEngComm 2015. [DOI: 10.1039/c5ce00186b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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44
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Blume R, Kidambi PR, Bayer BC, Weatherup RS, Wang ZJ, Weinberg G, Willinger MG, Greiner M, Hofmann S, Knop-Gericke A, Schlögl R. The influence of intercalated oxygen on the properties of graphene on polycrystalline Cu under various environmental conditions. Phys Chem Chem Phys 2014; 16:25989-6003. [PMID: 25356600 DOI: 10.1039/c4cp04025b] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Intercalation of oxygen at the interface of graphene grown by chemical vapour deposition and its polycrystalline copper catalyst can have a strong impact on the electronic, chemical and structural properties of both the graphene and the Cu. This can affect the oxidation resistance of the metal as well as subsequent graphene transfer. Here, we show, using near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS), X-ray absorption near edge spectroscopy (XANES), energy dispersive X-ray spectroscopy (EDX) and (environmental) scanning electron microscopy (ESEM) that both the oxygen intercalation and de-intercalation are kinetically driven and can be clearly distinguished from carbon etching. The obtained results reveal that a charge transfer between as grown graphene and Cu can be annulled by intercalating oxygen creating quasi-free-standing graphene. This effect is found to be reversible on vacuum annealing proceeding via graphene grain boundaries and defects within the graphene but not without loss of graphene by oxidative etching for repeated (de-)intercalation cycles.
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Affiliation(s)
- Raoul Blume
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, D-12489 Berlin, Germany.
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45
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Huang X, Willinger MG, Fan H, Xie ZL, Wang L, Klein-Hoffmann A, Girgsdies F, Lee CS, Meng XM. Single crystalline wurtzite ZnO/zinc blende ZnS coaxial heterojunctions and hollow zinc blende ZnS nanotubes: synthesis, structural characterization and optical properties. Nanoscale 2014; 6:8787-8795. [PMID: 24954555 DOI: 10.1039/c4nr01575d] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Synthesis of ZnO/ZnS heterostructures under thermodynamic conditions generally results in the wurtzite (WZ) structure of the ZnS component because its WZ phase is thermodynamically more stable than its zinc blende (ZB) phase. In this report, we demonstrate for the first time the preparation of ZnO/ZnS coaxial nanocables composed of single crystalline ZB structured ZnS epitaxially grown on WZ ZnO via a two-step thermal evaporation method. The deposition temperature is believed to play a crucial role in determining the crystalline phase of ZnS. Through a systematic structural analysis, the ZnO core and the ZnS shell are found to have an orientation relationship of (0002)ZnO(WZ)//(002)ZnS(ZB) and [01-10]ZnO(WZ)//[2-20]ZnS(ZB). Observation of the coaxial nanocables in cross-section reveals the formation of voids between the ZnO core and the ZnS shell during the coating process, which is probably associated with the nanoscale Kirkendall effect known to result in porosity. Furthermore, by immersing the ZnO/ZnS nanocable heterojunctions in an acetic acid solution to etch away the inner ZnO cores, single crystalline ZnS nanotubes orientated along the [001] direction of the ZB structure were also achieved for the first time. Finally, optical properties of the hollow ZnS tubes were investigated and discussed in detail. We believe that our study could provide some insights into the controlled fabrication of one dimensional (1D) semiconductors with desired morphology, structure and composition at the nanoscale, and the synthesized WZ ZnO/ZB ZnS nanocables as well as ZB ZnS nanotubes could be ideal candidates for the study of optoelectronics based on II-VI semiconductors.
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Affiliation(s)
- Xing Huang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
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Zhao A, Masa J, Xia W, Maljusch A, Willinger MG, Clavel G, Xie K, Schlögl R, Schuhmann W, Muhler M. Spinel Mn–Co Oxide in N-Doped Carbon Nanotubes as a Bifunctional Electrocatalyst Synthesized by Oxidative Cutting. J Am Chem Soc 2014; 136:7551-4. [DOI: 10.1021/ja502532y] [Citation(s) in RCA: 255] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Anqi Zhao
- Laboratory
of Industrial Chemistry, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Justus Masa
- Analytical
Chemistry - Center for Electrochemical Sciences (CES), Ruhr-University Bochum, D-44780 Bochum, Germany
| | - Wei Xia
- Laboratory
of Industrial Chemistry, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Artjom Maljusch
- Analytical
Chemistry - Center for Electrochemical Sciences (CES), Ruhr-University Bochum, D-44780 Bochum, Germany
| | | | - Guylhaine Clavel
- Fritz-Haber
Institute of the Max-Planck Society, 14195 Berlin, Germany
| | - Kunpeng Xie
- Laboratory
of Industrial Chemistry, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Robert Schlögl
- Fritz-Haber
Institute of the Max-Planck Society, 14195 Berlin, Germany
| | - Wolfgang Schuhmann
- Analytical
Chemistry - Center for Electrochemical Sciences (CES), Ruhr-University Bochum, D-44780 Bochum, Germany
| | - Martin Muhler
- Laboratory
of Industrial Chemistry, Ruhr-University Bochum, 44801 Bochum, Germany
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Hill LJ, Richey NE, Sung Y, Dirlam PT, Griebel JJ, Lavoie-Higgins E, Shim IB, Pinna N, Willinger MG, Vogel W, Benkoski JJ, Char K, Pyun J. Colloidal polymers from dipolar assembly of cobalt-tipped CdSe@CdS nanorods. ACS Nano 2014; 8:3272-3284. [PMID: 24645795 DOI: 10.1021/nn406104d] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The synthesis of a modular colloidal polymer system based on the dipolar assembly of CdSe@CdS nanorods functionalized with a single cobalt nanoparticle "tip" (CoNP-tip) is reported. These heterostructured nanorods spontaneously self-assembled via magnetic dipolar associations of the cobalt domains. In these assemblies, CdSe@CdS nanorods were carried as densely grafted side chain groups along the dipolar NP chain to form bottlebrush-type colloidal polymers. Nanorod side chains strongly affected the conformation of individual colloidal polymer bottlebrush chains and the morphology of thin films. Dipolar CoNP-tipped nanorods were then used as "colloidal monomers" to form mesoscopic assemblies reminiscent of traditional copolymers possessing segmented and statistical compositions. Investigation of the phase behavior of colloidal polymer blends revealed the formation of mesoscopic phase separated morphologies from segmented colloidal copolymers. These studies demonstrated the ability to control colloidal polymer composition and morphology in a manner observed for classical polymer systems by synthetic control of heterostructured nanorod structure and harnessing interparticle dipolar associations.
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Affiliation(s)
- Lawrence J Hill
- Department of Chemistry and Biochemistry, University of Arizona , 1306 East University Boulevard, Tucson, Arizona 85721, United States
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Maurin-Pasturel G, Long J, Guari Y, Godiard F, Willinger MG, Guerin C, Larionova J. Back Cover: Nanosized Heterostructures of Au@Prussian Blue Analogues: Towards Multifunctionality at the Nanoscale (Angew. Chem. Int. Ed. 15/2014). Angew Chem Int Ed Engl 2014. [DOI: 10.1002/anie.201401097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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49
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Maurin-Pasturel G, Long J, Guari Y, Godiard F, Willinger MG, Guerin C, Larionova J. Rücktitelbild: Nanosized Heterostructures of Au@Prussian Blue Analogues: Towards Multifunctionality at the Nanoscale (Angew. Chem. 15/2014). Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201401097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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50
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Busser GW, Mei B, Pougin A, Strunk J, Gutkowski R, Schuhmann W, Willinger MG, Schlögl R, Muhler M. Photodeposition of copper and chromia on gallium oxide: the role of co-catalysts in photocatalytic water splitting. ChemSusChem 2014; 7:1030-1034. [PMID: 24591306 DOI: 10.1002/cssc.201301065] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 01/09/2014] [Indexed: 06/03/2023]
Abstract
Split second: The photocatalytic activity of gallium oxide (β-Ga2 O3) depends strongly on the co-catalysts CuOx and chromia, which can be efficiently deposited in a stepwise manner by photoreduction of Cu(2+) and CrO4 (2-). The water-splitting activity can be tuned by varying the Cu loading in the range 0.025-1.5 wt %, whereas the Cr loading is not affecting the rate as long as small amounts (such as 0.05 wt %) are present. Chromia is identified as highly efficient co-catalyst in the presence of CuOx : it is essential for the oxidation of water.
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Affiliation(s)
- G Wilma Busser
- Laboratory of Industrial Chemistry, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany), Fax: (+49) 0234-32-14115
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