1
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Onur E, Lee J, Aymerich-Armengol R, Lim J, Dai Y, Tüysüz H, Scheu C, Weidenthaler C. Exploring the Effects of the Photochromic Response and Crystallization on the Local Structure of Noncrystalline Niobium Oxide. ACS Appl Mater Interfaces 2024; 16:25136-25147. [PMID: 38687307 PMCID: PMC11103654 DOI: 10.1021/acsami.4c04038] [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] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/02/2024]
Abstract
Niobium oxide (Nb2O5) is a versatile semiconductor material with photochromic properties. This study investigates the local structure of noncrystalline, short-range-ordered niobium oxide synthesized via a sol-gel method. X-ray atomic pair distribution function analysis unravels the structural arrangements within the noncrystalline materials at a local scale. In the following, in situ scattering and diffraction experiments elucidate the heat-induced structure transformation of the amorphous material into crystalline TT-Nb2O5 at 550 °C. In addition, the effect of photocatalytic conditions on the structure of the material was investigated by exposing the short-range-ordered and crystalline materials to ultraviolet light, resulting in a reversible color change from white to dark brown or blue. This photochromic response is due to the reversible elongation of the nearest Nb-O neighbors, as shown by local structure analysis based on in situ PDF analyses. Optical band gap calculations based on the ultraviolet-visible spectra collected for both the short-range-ordered and crystalline materials show that the band gap values reduced for the darkened materials return to their initial state after bleaching. Furthermore, electron energy loss spectroscopy reveals the reduction of Nb5+ to Nb4+ centers as a persistent effect. The study establishes a correlation between the band gap and the structure of niobium oxide, providing insights into the structure-performance relation at the atomic level.
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Affiliation(s)
- Ezgi Onur
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Jinsun Lee
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | | | - Joohyun Lim
- Max-Planck-Institut
für Eisenforschung, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Yitao Dai
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Harun Tüysüz
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Christina Scheu
- Max-Planck-Institut
für Eisenforschung, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Claudia Weidenthaler
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
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2
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Jang K, Kim MY, Jung C, Kim SH, Choi D, Park SC, Scheu C, Choi PP. Direct Observation of Trace Elements in Barium Titanate of Multilayer Ceramic Capacitors Using Atom Probe Tomography. Microsc Microanal 2024:ozae032. [PMID: 38702984 DOI: 10.1093/mam/ozae032] [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] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 02/29/2024] [Accepted: 03/22/2024] [Indexed: 05/06/2024]
Abstract
Accurately controlling trace additives in dielectric barium titanate (BaTiO3) layers is important for optimizing the performance of multilayer ceramic capacitors (MLCCs). However, characterizing the spatial distribution and local concentration of the additives, which strongly influence the MLCC performance, poses a significant challenge. Atom probe tomography (APT) is an ideal technique for obtaining this information, but the extremely low electrical conductivity and piezoelectricity of BaTiO3 render its analysis with existing sample preparation approaches difficult. In this study, we developed a new APT sample preparation method involving W coating and heat treatment to investigate the trace additives in the BaTiO3 layer of MLCCs. This method enables determination of the local concentration and distribution of all trace elements in the BaTiO3 layer, including additives and undesired impurities. The developed method is expected to pave the way for the further optimization and advancement of MLCC technology.
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Affiliation(s)
- Kyuseon Jang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Mi-Yang Kim
- Analysis and Interface Technology group, Corporate R&D Institute, Samsung Electro-Mechanics Co. Ltd., 150 Maeyeong-ro, Yeongtong-gu, Suwon 16674, Republic of Korea
| | - Chanwon Jung
- Department of Nanoanalytics and Interfaces, Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany
- Department of Materials Science and Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan 48513, Republic of Korea
| | - Se-Ho Kim
- Department of Nanoanalytics and Interfaces, Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany
- Department of Materials Science and Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Daechul Choi
- Analysis and Interface Technology group, Corporate R&D Institute, Samsung Electro-Mechanics Co. Ltd., 150 Maeyeong-ro, Yeongtong-gu, Suwon 16674, Republic of Korea
| | - Seong-Chan Park
- Analysis and Interface Technology group, Corporate R&D Institute, Samsung Electro-Mechanics Co. Ltd., 150 Maeyeong-ro, Yeongtong-gu, Suwon 16674, Republic of Korea
| | - Christina Scheu
- Department of Nanoanalytics and Interfaces, Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany
| | - Pyuck-Pa Choi
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
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3
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Cheraparambil H, Vega-Paredes M, Scheu C, Weidenthaler C. Unraveling the Evolution of Dynamic Active Sites of LaNi xFe 1-xO 3 Catalysts During OER. ACS Appl Mater Interfaces 2024; 16:21997-22006. [PMID: 38647135 PMCID: PMC11071036 DOI: 10.1021/acsami.4c02502] [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] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/10/2024] [Accepted: 04/14/2024] [Indexed: 04/25/2024]
Abstract
Perovskites have attracted tremendous attention as potential catalysts for the oxygen evolution reaction (OER). It is well-known that the introduction of Fe into rare earth perovskites such as LaNiO3 enhances the intrinsic OER activity. Despite numerous studies on structure-property relationships, the origin of the activity and the nature of the active species are still elusive and unclear. In this work, we study a series of LaNixFe1-xO3 perovskites using in situ electrochemical surface-enhanced Raman spectroscopy and electron energy loss spectroscopy to decipher the surface evolution and formation of active species during OER. While the origin of the activity arises from NiOOH species formed from the active Ni centers in LaNiO3, our work shows that Fe serves as the active center in LaNi0.5Fe0.5O3 and forms Fe-O-Ni and FeOOH species during OER. The OER activity of LaFeO3 originates from FeOOH species, which interact with the soluble Ni species in the electrolyte forming an active electrode-electrolyte interface with high-valent stable surface iron species (Fe4+) and thereby improving the performance. Our work provides deeper insights into the synergistic effects of Ni and Fe on the catalytic activity, which in turn provides new design principles for perovskite catalysts for the OER.
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Affiliation(s)
- Haritha Cheraparambil
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Miquel Vega-Paredes
- Max-Planck-Institut
für Eisenforschung, Max-Planck-Straße 1, Düsseldorf 40237, Germany
| | - Christina Scheu
- Max-Planck-Institut
für Eisenforschung, Max-Planck-Straße 1, Düsseldorf 40237, Germany
| | - Claudia Weidenthaler
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
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4
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Rivas NAR, Manjón AG, Vega-Paredes M, Kim SH, Gault B, Jun H, Jung C, Berova V, Hengge K, Jurzinsky T, Scheu C. Chemistry and microstructure of C-supported Ru catalyst nanoparticles: A correlative study. Ultramicroscopy 2023; 254:113831. [PMID: 37597307 DOI: 10.1016/j.ultramic.2023.113831] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 07/31/2023] [Accepted: 08/09/2023] [Indexed: 08/21/2023]
Abstract
Ru@Pt core shell nanoparticles possess optimal catalytic properties that facilitate the anodic oxidation reaction of H2 with decreased Pt loading in hydrogen fuel cells. Moreover, since they preferentially oxidize CO, Pt poisoning is considerably reduced, which significantly improves the stability of the cell. The Ru cores used in this system are usually synthesized by dissolving a RuCl3*H2O precursor in an ethylene glycol-carbon black-NaOH mixture. However, the possibility that remnant Cl and Na from the synthesis process are present in the Ru nanoparticles has not been extensively studied. Therefore, due to the challenges in detecting impurities with traditional characterization methods, here correlative atom probe tomography (APT) with scanning transmission electron microscopy ((S)TEM) techniques were implemented. The capabilities of APT to obtain chemical information with high sensitivity at the nanoscale, in combination with the high spatial resolving power of (S)TEM, provide the necessary resolution to fully characterize the structure and chemical makeup of Ru nanoparticles.
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Affiliation(s)
- Nicolás A Rivas Rivas
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany.
| | - Alba Garzón Manjón
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany
| | - Miquel Vega-Paredes
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany
| | - Se-Ho Kim
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany
| | - Baptiste Gault
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany; Department of Materials, Royal School of Mines, Imperial College, London SW7 2AZ, United Kingdom
| | - Hosun Jun
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Chanwon Jung
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany; Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Viktoriya Berova
- Freudenberg Fuel Cell e-Power Systems GmbH, Bayerwaldstraße 3, München 81737, Germany
| | - Katharina Hengge
- Freudenberg Fuel Cell e-Power Systems GmbH, Bayerwaldstraße 3, München 81737, Germany
| | - Tilman Jurzinsky
- Freudenberg Fuel Cell e-Power Systems GmbH, Bayerwaldstraße 3, München 81737, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf 40237, Germany.
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5
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Sahu R, Bogdanovski D, Achenbach JO, Hans M, Primetzhofer D, Schneider JM, Scheu C. Compositional defects in a MoAlB MAB phase thin film grown by high-power pulsed magnetron sputtering. Nanoscale 2023; 15:17356-17363. [PMID: 37876283 DOI: 10.1039/d3nr04233b] [Citation(s) in RCA: 1] [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] [Indexed: 10/26/2023]
Abstract
Various compositional defects such as Mo3Al2B4, Mo4Al3B4, Mo6Al5B6 and Al3Mo, together with MoB MBene, are observed to be coexisting in a MoAlB MAB phase thin film grown at 800 °C by high-power pulsed magnetron sputtering. An overall film composition of Mo0.29Al0.33B0.38 is measured by time-of-flight elastic recoil detection analysis. The concurrent formation of these compositional defects in the MoAlB matrix occurs during the synthesis without using any chemical reagent, and their coexistence with the MAB phase is thermodynamically possible, as elucidated by density functional theory simulations. These defect phases are imaged at the atomic scale by aberration-corrected scanning transmission electron microscopy. A rough estimation of defect populations of 0.073, 0.037, 0.042 and 0.039 nm-1 for Mo3Al2B4, Mo4Al3B4, Mo6Al5B6 and Al3Mo compositional defects, respectively, is performed within the MoAlB matrix. The calculated energies of formation reveal that the Mo4Al3B4 and Mo6Al5B6 defect phases form spontaneously in the MoAlB host matrix, while the energy barrier towards the formation of the metastable Mo3Al2B4 phase is approx. 20 meV per atom. The small magnitude of this barrier is easily overcome during vapor phase condensation, and the surface diffusion of adatoms during deposition leads to local compositional variations and the coexistence of the defect phases in the host matrix. Additionally, at grain boundaries, the presence of MoB MBene is observed, with an interlayer spacing between two Mo2B2 units increasing up to ∼50% compared to the pristine MoAlB phase.
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Affiliation(s)
- Rajib Sahu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany.
| | - Dimitri Bogdanovski
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany.
| | - Jan-Ole Achenbach
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany.
| | - Marcus Hans
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany.
| | - Daniel Primetzhofer
- Department of Physics and Astronomy, Uppsala University, Box 516, S-75120 Uppsala, Sweden
| | - Jochen M Schneider
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany.
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
- Materials Analytics, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
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6
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Vega-Paredes M, Scheu C, Aymerich-Armengol R. Expanding the Potential of Identical Location Scanning Transmission Electron Microscopy for Gas Evolving Reactions: Stability of Rhenium Molybdenum Disulfide Nanocatalysts for Hydrogen Evolution Reaction. ACS Appl Mater Interfaces 2023; 15:46895-46901. [PMID: 37774099 PMCID: PMC10571005 DOI: 10.1021/acsami.3c09188] [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] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 09/15/2023] [Indexed: 10/01/2023]
Abstract
Identical location (scanning) transmission electron microscopy provides valuable insights into the mechanisms of the activity and degradation of nanocatalysts during electrochemical reactions. However, the technique suffers from limitations that hinder its widespread use for nanocatalysts of gas evolving reactions, e.g., the hydrogen evolution reaction (HER). The main issue is the production of bubbles that cause the loss of electric contact in identical location measurements, which is critical for the correct cycling of the nanocatalysts and interpretation of the electron microscopy results. Herein, we systematically evaluate different set-ups, materials, and tools to allow the facile and reliable study of the stability of HER nanocatalysts. The optimized conditions are applied for the study of layered rhenium molybdenum disulfide (Re0.2Mo0.8S2) nanocatalysts, a relevant alternative to Pt catalysts for the HER. With our approach, we demonstrate that although the morphology of the Re0.2Mo0.8S2 catalyst is maintained during HER, chemical composition changes could be correlated to the electrochemical reaction. This study expands the potential of the IL(S)TEM technique for the construction of structure-property relationships of nanocatalysts of gas evolving reactions.
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Affiliation(s)
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung
GmbH, Max-Planck-Strasse 1, Düsseldorf 40237, Germany
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7
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Jung C, Zhang S, Jang K, Cheng N, Scheu C, Yi SH, Choi PP. Effect of Heat Treatment Temperature on the Crystallization Behavior and Microstructural Evolution of Amorphous NbCo 1.1Sn. ACS Appl Mater Interfaces 2023; 15:46064-46073. [PMID: 37738356 PMCID: PMC10561143 DOI: 10.1021/acsami.3c10298] [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] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 09/11/2023] [Indexed: 09/24/2023]
Abstract
Heat treatment-induced nanocrystallization of amorphous precursors is a promising method for nanostructuring half-Heusler compounds as it holds significant potential in the fabrication of intricate and customizable nanostructured materials. To fully exploit these advantages, a comprehensive understanding of the crystallization behavior of amorphous precursors under different crystallization conditions is crucial. In this study, we investigated the crystallization behavior of the amorphous NbCo1.1Sn alloy at elevated temperatures (783 and 893 K) using transmission electron microscopy and atom probe tomography. As a result, heat treatment at 893 K resulted in a significantly finer grain structure than heat treatment at 783 K owing to the higher nucleation rate at 893 K. At both temperatures, the predominant phase was a half-Heusler phase, whereas the Heusler phase, associated with Co diffusion, was exclusively observed at the specimen annealed at 893 K. The Debye-Callaway model supports that the lower lattice thermal conductivity of NbCo1.1Sn annealed at 893 K is primarily attributed to the formation of Heusler nanoprecipitates rather than a finer grain size. The experimental findings of this study provide valuable insights into the nanocrystallization of amorphous alloys for enhancing thermoelectric properties.
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Affiliation(s)
- Chanwon Jung
- Department
of Materials Science and Engineering, Korea
Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- Max-Planck-Institut
für Eisenforschung, Max-Planck-Straße 1, Düsseldorf 40237, Germany
| | - Siyuan Zhang
- Max-Planck-Institut
für Eisenforschung, Max-Planck-Straße 1, Düsseldorf 40237, Germany
| | - Kyuseon Jang
- Department
of Materials Science and Engineering, Korea
Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Ningyan Cheng
- Max-Planck-Institut
für Eisenforschung, Max-Planck-Straße 1, Düsseldorf 40237, Germany
| | - Christina Scheu
- Max-Planck-Institut
für Eisenforschung, Max-Planck-Straße 1, Düsseldorf 40237, Germany
| | - Seong-Hoon Yi
- Department
of Materials Science and Metallurgical Engineering, Kyungpook National University, 80 Daehakro, Daegu 41566, Republic of Korea
| | - Pyuck-Pa Choi
- Department
of Materials Science and Engineering, Korea
Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
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8
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Vega-Paredes M, Aymerich-Armengol R, Arenas Esteban D, Martí-Sánchez S, Bals S, Scheu C, Garzón Manjón A. Electrochemical Stability of Rhodium-Platinum Core-Shell Nanoparticles: An Identical Location Scanning Transmission Electron Microscopy Study. ACS Nano 2023; 17:16943-16951. [PMID: 37602824 PMCID: PMC10510721 DOI: 10.1021/acsnano.3c04039] [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] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/16/2023] [Indexed: 08/22/2023]
Abstract
Rhodium-platinum core-shell nanoparticles on a carbon support (Rh@Pt/C NPs) are promising candidates as anode catalysts for polymer electrolyte membrane fuel cells. However, their electrochemical stability needs to be further explored for successful application in commercial fuel cells. Here we employ identical location scanning transmission electron microscopy to track the morphological and compositional changes of Rh@Pt/C NPs during potential cycling (10 000 cycles, 0.06-0.8 VRHE, 0.5 H2SO4) down to the atomic level, which are then used for understanding the current evolution occurring during the potential cycles. Our results reveal a high stability of the Rh@Pt/C system and point toward particle detachment from the carbon support as the main degradation mechanism.
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Affiliation(s)
- Miquel Vega-Paredes
- Max-Planck-Institut
für Eisenforschung GmbH (MPIE), Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Raquel Aymerich-Armengol
- Max-Planck-Institut
für Eisenforschung GmbH (MPIE), Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Daniel Arenas Esteban
- Electron
Microscopy for Materials Science (EMAT), University of Antwerp, 2020 Antwerp, Belgium
| | - Sara Martí-Sánchez
- Catalan
Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, 08193 Bellaterra, Spain
| | - Sara Bals
- Electron
Microscopy for Materials Science (EMAT), University of Antwerp, 2020 Antwerp, Belgium
| | - Christina Scheu
- Max-Planck-Institut
für Eisenforschung GmbH (MPIE), Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Alba Garzón Manjón
- Max-Planck-Institut
für Eisenforschung GmbH (MPIE), Max-Planck-Straße 1, 40237 Düsseldorf, Germany
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9
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Luo W, Xie Z, Zhang S, Guénolé J, Sun PL, Meingast A, Alhassan A, Zhou X, Stein F, Pizzagalli L, Berkels B, Scheu C, Korte-Kerzel S. Tailoring the Plasticity of Topologically Close-Packed Phases via the Crystals' Fundamental Building Blocks. Adv Mater 2023; 35:e2300586. [PMID: 36930795 DOI: 10.1002/adma.202300586] [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] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/03/2023] [Indexed: 06/16/2023]
Abstract
Brittle topologically close-packed precipitates form in many advanced alloys. Due to their complex structures, little is known about their plasticity. Here, a strategy is presented to understand and tailor the deformability of these complex phases by considering the Nb-Co µ-phase as an archetypal material. The plasticity of the Nb-Co µ-phase is controlled by the Laves phase building block that forms parts of its unit cell. It is found that between the bulk C15-NbCo2 Laves and Nb-Co µ-phases, the interplanar spacing and local stiffness of the Laves phase building block change, leading to a strong reduction in hardness and stiffness, as well as a transition from synchroshear to crystallographic slip. Furthermore, as the composition changes from Nb6 Co7 to Nb7 Co6 , the Co atoms in the triple layer are substituted such that the triple layer of the Laves phase building block becomes a slab of pure Nb, resulting in inhomogeneous changes in elasticity and a transition from crystallographic slip to a glide-and-shuffle mechanism. These findings open opportunities to purposefully tailor the plasticity of these topologically close-packed phases in the bulk by manipulating the interplanar spacing and local shear modulus of the fundamental crystal building blocks at the atomic scale.
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Affiliation(s)
- Wei Luo
- Institute for Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstraße 14, 52074, Aachen, Germany
| | - Zhuocheng Xie
- Institute for Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstraße 14, 52074, Aachen, Germany
| | - Siyuan Zhang
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Julien Guénolé
- CNRS, Arts et Métiers ParisTech, Université de Lorraine, LEM3, Metz, 57070, France
- Labex Damas, Université de Lorraine, Metz, 57070, France
| | - Pei-Ling Sun
- Institute for Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstraße 14, 52074, Aachen, Germany
| | - Arno Meingast
- Thermo Fisher Scientific, De Schakel 2, Eindhoven, 5651 GH, The Netherlands
| | - Amel Alhassan
- Institute for Advanced Study in Computational Engineering Science, RWTH Aachen University, Schinkelstr. 2, 52062, Aachen, Germany
| | - Xuyang Zhou
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Frank Stein
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Laurent Pizzagalli
- Institut Pprime, CNRS UPR 3346, Université de Poitiers, SP2MI, Boulevard Marie et Pierre Curie, TSA 41123, Poitiers Cedex 9, Poitiers, 86073, France
| | - Benjamin Berkels
- Institute for Advanced Study in Computational Engineering Science, RWTH Aachen University, Schinkelstr. 2, 52062, Aachen, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Sandra Korte-Kerzel
- Institute for Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstraße 14, 52074, Aachen, Germany
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10
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Changizi R, Zaefferer S, Ziegler C, Romaka V, Lotsch BV, Scheu C. Combined structural analysis and cathodoluminescence investigations of single Pr 3+-doped Ca 2Nb 3O 10 nanosheets. Sci Rep 2023; 13:8055. [PMID: 37198254 DOI: 10.1038/s41598-023-35142-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 05/13/2023] [Indexed: 05/19/2023] Open
Abstract
Due to the novel properties of both 2D materials and rare-earth elements, developing 2D rare-earth nanomaterials has a growing interest in research. To produce the most efficient rare-earth nanosheets, it is essential to find out the correlation between chemical composition, atomic structure and luminescent properties of individual sheets. In this study, 2D nanosheets exfoliated from Pr3+-doped KCa2Nb3O10 particles with different Pr concentrations were investigated. Energy dispersive X-ray spectroscopy analysis indicates that the nanosheets contain Ca, Nb and O and a varying Pr content between 0.9 and 1.8 at%. K was completely removed after exfoliation. The crystal structure is monoclinic as in the bulk. The thinnest nanosheets are 3 nm corresponding to one triple perovskite-type layer with Nb on the B sites and Ca on the A sites, surrounded by charge compensating TBA+ molecules. Thicker nanosheets of 12 nm thickness (and above) were observed too by transmission electron microscopy with the same chemical composition. This indicates that several perovskite-type triple layers remain stacked similar to the bulk. Luminescent properties of individual 2D nanosheets were studied using a cathodoluminescence spectrometer revealing additional transitions in the visible region in comparison to the spectra of different bulk phases.
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Affiliation(s)
- Rasa Changizi
- Max-Planck-Institut Für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany.
| | - Stefan Zaefferer
- Max-Planck-Institut Für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Christian Ziegler
- Department of Chemistry, University of Munich (LMU), Butenandtstraße 5-13, 81377, München, Germany
| | - Vitaliy Romaka
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
| | - Bettina V Lotsch
- Department of Chemistry, University of Munich (LMU), Butenandtstraße 5-13, 81377, München, Germany
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569, Stuttgart, Germany
| | - Christina Scheu
- Max-Planck-Institut Für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
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11
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Chen Z, Wang X, Han Z, Zhang S, Pollastri S, Fan Q, Qu Z, Sarker D, Scheu C, Huang M, Cölfen H. Revealing the Formation Mechanism and Optimizing the Synthesis Conditions of Layered Double Hydroxides for the Oxygen Evolution Reaction. Angew Chem Int Ed Engl 2023; 62:e202215728. [PMID: 36588090 DOI: 10.1002/anie.202215728] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 10/25/2022] [Revised: 12/27/2022] [Accepted: 12/30/2022] [Indexed: 01/03/2023]
Abstract
Layered double hydroxides (LDHs), whose formation is strongly related to OH- concentration, have attracted significant interest in various fields. However, the effect of the real-time change of OH- concentration on LDHs' formation has not been fully explored due to the unsuitability of the existing synthesis methods for in situ characterization. Here, the deliberately designed combination of NH3 gas diffusion and in situ pH measurement provides a solution to the above problem. The obtained results revealed the formation mechanism and also guided us to synthesize a library of LDHs with the desired attributes in water at room temperature without using any additives. After evaluating their oxygen evolution reaction performance, we found that FeNi-LDH with a Fe/Ni ratio of 25/75 exhibits one of the best performances so far reported.
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Affiliation(s)
- Zongkun Chen
- University of Konstanz, 78457, Konstanz, Germany
| | - Xingkun Wang
- School of Materials Science and Engineering, Ocean University of China, 266100, Qingdao, China
| | - Zhongkang Han
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195, Berlin, Germany
| | - Siyuan Zhang
- Max-Planck-Institut für Eisenforschung GmbH, 40237, Düsseldorf, Germany
| | | | - Qiqi Fan
- University of Konstanz, 78457, Konstanz, Germany
| | - Zhengyao Qu
- Agency for Science, Technology and Research, Singapore, 138634, Singapore
| | - Debalaya Sarker
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195, Berlin, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, 40237, Düsseldorf, Germany
| | - Minghua Huang
- School of Materials Science and Engineering, Ocean University of China, 266100, Qingdao, China
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Chen Z, Wang X, Han Z, Zhang S, Pollastri S, Fan Q, Qu Z, Sarker D, Scheu C, Huang M, Cölfen H. Revealing the Formation Mechanism and Optimizing the Synthesis Conditions of Layered Double Hydroxides for the Oxygen Evolution Reaction. Angew Chem Int Ed Engl 2023. [DOI: 10.1002/ange.202215728] [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: 01/03/2023]
Affiliation(s)
- Zongkun Chen
- University of Konstanz: Universitat Konstanz University of Konstanz GERMANY
| | - Xingkun Wang
- Ocean University of China School of Materials Science and Engineering CHINA
| | - Zhongkang Han
- Fritz-Haber-Institut der MPG Berlin: Fritz-Haber-Institut der Max-Planck-Gesellschaft Fritz-Haber-Institut der Max-Planck-Gesellschaft GERMANY
| | - Siyuan Zhang
- Max-Planck-Institut für Eisenforschung GmbH: Max-Planck-Institut fur Eisenforschung GmbH Max-Planck-Institut für Eisenforschung GmbH GERMANY
| | - Simone Pollastri
- Elettra Sincrotrone Trieste SCpA Elettra-Sincrotrone Trieste ITALY
| | - Qiqi Fan
- University of Konstanz: Universitat Konstanz University of Konstanz GERMANY
| | - Zhengyao Qu
- Agency of Science, Technology and Research Agency for Science, Technology and Research SINGAPORE
| | - Debalaya Sarker
- Fritz-Haber-Institut der MPG Berlin: Fritz-Haber-Institut der Max-Planck-Gesellschaft Fritz-Haber-Institut der Max-Planck-Gesellschaft GERMANY
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH: Max-Planck-Institut fur Eisenforschung GmbH Max-Planck-Institut für Eisenforschung GmbH GERMANY
| | - Minghua Huang
- Ocean University of China School of Materials Science and Engineering CHINA
| | - Helmut Cölfen
- University of Konstanz Physical Chemistry Universitätsstraße 10 78457 Konstanz GERMANY
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Onur Şahin E, Zhang S, Scheu C, Weidenthaler C. Sodium Tantalates: Monitoring Crystallization via in situ Total X-Ray Scattering. CrystEngComm 2023. [DOI: 10.1039/d3ce00121k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Sodium tantalates, which have potential applications in photocatalysis, microelectronics and energy harvesting, are known to crystallize into several polymorphs on which the electrical and optical properties are dependent. As a...
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Garzón Manjón A, Vega-Paredes M, Berova V, Gänsler T, Schwarz T, Rivas Rivas NA, Hengge K, Jurzinsky T, Scheu C. Insights into the performance and degradation of Ru@Pt core-shell catalysts for fuel cells by advanced (scanning) transmission electron microscopy. Nanoscale 2022; 14:18060-18069. [PMID: 36448460 DOI: 10.1039/d2nr04869h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Ru@Pt core-shell nanoparticles are currently being explored as carbon monoxide tolerant anode catalysts for proton exchange membrane fuel cells. However, little is known about their degradation under fuel cell conditions. In the present work, two types of Ru@Pt nanoparticles with nominal shell thicknesses of 1 (Ru@1Pt) and 2 (Ru@2Pt) Pt monolayers are studied as synthesized and after accelerated stress tests. These stress tests were designed to imitate the degradation occurring under fuel cell operating conditions. Our advanced (scanning) transmission electron microscopy characterization explains the superior initial electrochemical performance of Ru@1Pt. Moreover, the 3D reconstruction of the Pt shell by electron tomography reveals an incomplete shell for both samples, which results in a less stable Ru metal being exposed to an electrolyte. The degree of coverage of the Ru cores provides insights into the higher stability of Ru@2Pt during the accelerated stress tests. Our results explain how to maximize the initial performance of Ru@Pt-type catalysts, without compromising their stability under fuel cell conditions.
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Affiliation(s)
- Alba Garzón Manjón
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
| | - Miquel Vega-Paredes
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
| | - Viktoriya Berova
- Freudenberg Fuel Cell e-Power Systems GmbH, Bayerwaldstraße 3, 81737 München, Germany
| | - Thomas Gänsler
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
| | - Torsten Schwarz
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
| | - Nicolas A Rivas Rivas
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
| | - Katharina Hengge
- Freudenberg Fuel Cell e-Power Systems GmbH, Bayerwaldstraße 3, 81737 München, Germany
| | - Tilman Jurzinsky
- Freudenberg Fuel Cell e-Power Systems GmbH, Bayerwaldstraße 3, 81737 München, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
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15
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Zhang S, Xie Z, Keuter P, Ahmad S, Abdellaoui L, Zhou X, Cautaerts N, Breitbach B, Aliramaji S, Korte-Kerzel S, Hans M, Schneider JM, Scheu C. Atomistic structures of 〈0001〉 tilt grain boundaries in a textured Mg thin film. Nanoscale 2022; 14:18192-18199. [PMID: 36454106 DOI: 10.1039/d2nr05505h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Nanocrystalline Mg was sputter deposited onto an Ar ion etched Si {100} substrate. Despite an ∼6 nm amorphous layer found at the interface, the Mg thin film exhibits a sharp basal-plane texture enabled by surface energy minimization. The columnar grains have abundant 〈0001〉 tilt grain boundaries in between, most of which are symmetric with various misorientation angles. Up to ∼20° tilt angle, they are composed of arrays of equally-spaced edge dislocations. Ga atoms were introduced from focused ion beam milling and found to segregate at grain boundaries and preferentially decorate the dislocation cores. Most symmetric grain boundaries are type-1, whose boundary planes have smaller dihedral angles with {21̄1̄0} rather than {101̄0}. Atomistic simulations further demonstrate that type-2 grain boundaries, having boundary planes at smaller dihedral angles with {101̄0}, are composed of denser dislocation arrays and hence have higher formation energy than their type-1 counterparts. The finding correlates well with the dominance of type-1 grain boundaries observed in the Mg thin film.
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Affiliation(s)
- Siyuan Zhang
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
| | - Zhuocheng Xie
- Institute for Physical Metallurgy and Materials Physics, RWTH Aachen University, 52074 Aachen, Germany
| | - Philipp Keuter
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Saba Ahmad
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
| | - Lamya Abdellaoui
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
| | - Xuyang Zhou
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
| | - Niels Cautaerts
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
| | - Benjamin Breitbach
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
| | - Shamsa Aliramaji
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Sandra Korte-Kerzel
- Institute for Physical Metallurgy and Materials Physics, RWTH Aachen University, 52074 Aachen, Germany
| | - Marcus Hans
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Jochen M Schneider
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
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Meischein M, Garzón-Manjón A, Hammerschmidt T, Xiao B, Zhang S, Abdellaoui L, Scheu C, Ludwig A. Elemental (im-)miscibility determines phase formation of multinary nanoparticles co-sputtered in ionic liquids. Nanoscale Adv 2022; 4:3855-3869. [PMID: 36133350 PMCID: PMC9470033 DOI: 10.1039/d2na00363e] [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] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/11/2022] [Indexed: 06/16/2023]
Abstract
Non-equilibrium synthesis methods allow the alloying of bulk-immiscible elements into multinary nanoparticles, which broadens the design space for new materials. Whereas sputtering onto solid substrates can combine immiscible elements into thin film solid solutions, this is not clear for sputtering of nanoparticles in ionic liquids. Thus, the suitability of sputtering in ionic liquids for producing nanoparticles of immiscible elements is investigated by co-sputtering the systems Au-Cu (miscible), Au-Ru and Cu-Ru (both immiscible), and Au-Cu-Ru on the surface of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [Bmim][(Tf)2N]. The sputtered nanoparticles were analyzed to obtain (i) knowledge concerning the general formation process of nanoparticles when sputtering onto ionic liquid surfaces and (ii) information, if alloy nanoparticles of immiscible elements can be synthesized as well as (iii) evidence if the Hume-Rothery rules for solid solubility are valid for sputtered nanoparticles. Nanoparticle characteristics were found to depend on elemental miscibility: (1) nanoparticles from immiscible elemental combinations showed bigger mean diameters ranging from (3.3 ± 1.4) nm to (5.0 ± 1.7) nm in contrast to mean diameters of nanoparticles from elemental combinations with at least one miscible element pair ((1.7 ± 0.7) nm to (1.8 ± 0.6) nm). (2) Nanoparticles from immiscible combinations showed compositions with one element strongly dominating the ratio and very narrow differences between the highest and lowest fraction of the dominating element (Cu94Ru6 to Cu100Ru0; Au96Ru4 to Au99Ru1) in contrast to the other compositions (Au64Cu36 to Au81Cu19; Au83Cu13Ru4/Au75Cu22Ru3 to Au87Cu11Ru2). Accompanying atomistic simulations using density-functional theory for clusters of different size and ordering confirm that the miscibility of Au-Cu and the immiscibility of Au-Ru and Cu-Ru govern the thermodynamic stability of the nanoparticles. Based on the matching experimental and theoretical results for the NP/IL-systems concerning NP stability, a formation model of multinary NPs in ILs was developed.
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Affiliation(s)
- Michael Meischein
- Chair for Materials Discovery and Interfaces, Institute for Materials, Faculty of Mechanical Engineering, Ruhr University Bochum Universitätsstr. 150 D-44780 Bochum Germany
| | - Alba Garzón-Manjón
- Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 1 D-0237 Düsseldorf Germany
| | - Thomas Hammerschmidt
- Chair of Atomistic Modelling and Simulation, Interdisciplinary Centre for Advanced Materials Simulation (ICAMS), Ruhr University Bochum Universitätsstr. 150 D-44780 Bochum Germany
| | - Bin Xiao
- Chair for Materials Discovery and Interfaces, Institute for Materials, Faculty of Mechanical Engineering, Ruhr University Bochum Universitätsstr. 150 D-44780 Bochum Germany
| | - Siyuan Zhang
- Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 1 D-0237 Düsseldorf Germany
| | - Lamya Abdellaoui
- Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 1 D-0237 Düsseldorf Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 1 D-0237 Düsseldorf Germany
| | - Alfred Ludwig
- Chair for Materials Discovery and Interfaces, Institute for Materials, Faculty of Mechanical Engineering, Ruhr University Bochum Universitätsstr. 150 D-44780 Bochum Germany
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Vega Paredes M, Garzón Manjón A, Hill B, Schwarz T, Rivas NA, Jurzinsky T, Hengge K, Mack F, Scheu C. Evaluation of functional layers thinning of high temperature polymer electrolyte membrane fuel cells after long term operation. Nanoscale 2022; 14:11543-11551. [PMID: 35815839 DOI: 10.1039/d2nr02892a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The operation related degradation processes of high temperature polymer electrolyte membrane fuel cell operated with hydrogen-rich reformate gas are studied. CO impurities from the reformate gas are strongly adsorbed by the catalyst surface, leading to poisoning and thus, reduction of the overall performance of the cell. Most of the studies are performed in a laboratory set-up by applying accelerated stress tests. In the present work, a high temperature polymer electrolyte membrane fuel cell is operated in a realistic configuration for 12 000 h (500 days). The fuel cell contains as electrocatalyst Pt in the cathode and a Pt-Ru alloy in the anode. The study of the degradation occurring in the functional layers, i.e. in different regions of cathode, anode and membrane layer, is carried out by scanning electron microscopy, (scanning) transmission electron microscopy and energy dispersive X-ray spectroscopy. We observed a thinning of the functional layers and a redistribution of catalyst material. The thinning of the cathode side is larger compared to the anode side due to harsher operation conditions likely causing a degradation of the support material via C corrosion and/or due to a degradation of the catalyst via oxidation of Pt and Ru. A thinning of the membrane caused by oxidation agents is also detected. Moreover, during operation, catalyst material is dissolved at the cathode side and redistributed. Our results will help to design and develop fuel cells with higher performance.
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Affiliation(s)
- Miquel Vega Paredes
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
| | - Alba Garzón Manjón
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
| | - Bjoern Hill
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
| | - Torsten Schwarz
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
| | - Nicolas A Rivas
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
| | - Tilman Jurzinsky
- Freudenberg Fuel Cell e-Power Systems GmbH, Bayerwaldstraße 3, 81737 München, Germany
| | - Katharina Hengge
- Freudenberg Fuel Cell e-Power Systems GmbH, Bayerwaldstraße 3, 81737 München, Germany
| | - Florian Mack
- Freudenberg Fuel Cell e-Power Systems GmbH, Bayerwaldstraße 3, 81737 München, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
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Kim SH, Yoo SH, Shin S, El-Zoka AA, Kasian O, Lim J, Jeong J, Scheu C, Neugebauer J, Lee H, Todorova M, Gault B. Controlled Doping of Electrocatalysts through Engineering Impurities. Adv Mater 2022; 34:e2203030. [PMID: 35514107 DOI: 10.1002/adma.202203030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 04/27/2022] [Indexed: 06/14/2023]
Abstract
Fuel cells recombine water from H2 and O2 thereby can power, for example, cars or houses with no direct carbon emission. In anion-exchange membrane fuel cells (AEMFCs), to reach high power densities, operating at high pH is an alternative to using large volumes of noble metals catalysts at the cathode, where the oxygen-reduction reaction occurs. However, the sluggish kinetics of the hydrogen-oxidation reaction (HOR) hinders upscaling despite promising catalysts. Here, the authors observe an unexpected ingress of B into Pd nanocatalysts synthesized by wet-chemistry, gaining control over this B-doping, and report on its influence on the HOR activity in alkaline conditions. They rationalize their findings using ab initio calculations of both H- and OH-adsorption on B-doped Pd. Using this "impurity engineering" approach, they thus design Pt-free catalysts as required in electrochemical energy conversion devices, for example, next generations of AEMFCs, that satisfy the economic and environmental constraints, that is, reasonable operating costs and long-term stability, to enable the "hydrogen economy."
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Affiliation(s)
- Se-Ho Kim
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Su-Hyun Yoo
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Sangyong Shin
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Ayman A El-Zoka
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Olga Kasian
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
- Helmholtz-Zentrum Berlin GmbH, Helmholtz Institut Erlangen-Nürnberg, 14109, Berlin, Germany
| | - Joohyun Lim
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
- Department of Chemistry, Kangwon National University, Chuncheon, 24342, Republic of Korea
| | - Jiwon Jeong
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Christina Scheu
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Jörg Neugebauer
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Hyunjoo Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Mira Todorova
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Baptiste Gault
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
- Department of Materials, Royal School of Mines, Imperial College, London, SW7 2AZ, UK
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Sahu R, Bogdanovski D, Achenbach JO, Schneider JM, Scheu C. Defects in an orthorhombic MoAlB MAB phase thin film grown at moderate synthesis temperature. Nanoscale 2022; 14:2578-2585. [PMID: 35107473 DOI: 10.1039/d1nr07792a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Here, we report on atomic scale characterization of various defects in a MoAlB (MAB) phase thin film grown by DC sputtering at a synthesis temperature of 700 °C. Aberration-corrected scanning transmission electron microscopy reveals the formation of an intergrown metastable Mo3Al2B4 phase accompanied by thermally stable 90° twist boundaries, coexisting within the pristine MoAlB matrix. The concurrent formation of these structural defects in the MoAlB matrix can be rationalized based on minute differences in formation enthalpies as shown via density functional theory calculations. The specific structural nature of both the twist boundary and compositional defect (Mo3Al2B4) in a MoAlB matrix is hitherto unreported in literature. Apart from these defects, faceted grain boundaries are observed. In the vicinity of amorphous AlOx regions, Al is deintercalated and a 2D MoB MBene phase is formed as reported before. Besides these amorphous AlOx regions, a few nanometer-sized 3D MoB clusters are found. The advancement of aberration-corrected scanning transmission electron microscopy significantly improves characterization from 1D to 3D defects which is important for thin film materials design for the moderate synthesis temperature range. The reported defects might play an important role in the formation of 2D MoB MBenes.
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Affiliation(s)
- Rajib Sahu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Dimitri Bogdanovski
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Jan-Ole Achenbach
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Jochen M Schneider
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
- Materials Analytics, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
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20
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Kim SH, Yoo SH, Chakraborty P, Jeong J, Lim J, El-Zoka AA, Zhou X, Stephenson LT, Hickel T, Neugebauer J, Scheu C, Todorova M, Gault B. Understanding Alkali Contamination in Colloidal Nanomaterials to Unlock Grain Boundary Impurity Engineering. J Am Chem Soc 2022; 144:987-994. [PMID: 34982554 PMCID: PMC8778649 DOI: 10.1021/jacs.1c11680] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Metal nanogels combine a large surface area, a high structural stability, and a high catalytic activity toward a variety of chemical reactions. Their performance is underpinned by the atomic-level distribution of their constituents, yet analyzing their subnanoscale structure and composition to guide property optimization remains extremely challenging. Here, we synthesized Pd nanogels using a conventional wet chemistry route, and a near-atomic-scale analysis reveals that impurities from the reactants (Na and K) are integrated into the grain boundaries of the poly crystalline gel, typically loci of high catalytic activity. We demonstrate that the level of impurities is controlled by the reaction condition. Based on ab initio calculations, we provide a detailed mechanism to explain how surface-bound impurities become trapped at grain boundaries that form as the particles coalesce during synthesis, possibly facilitating their decohesion. If controlled, impurity integration into grain boundaries may offer opportunities for designing new nanogels.
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Affiliation(s)
- Se-Ho Kim
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Su-Hyun Yoo
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Poulami Chakraborty
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Jiwon Jeong
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Joohyun Lim
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Ayman A El-Zoka
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Xuyang Zhou
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Leigh T Stephenson
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Tilmann Hickel
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Jörg Neugebauer
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Mira Todorova
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Baptiste Gault
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
- Department of Materials, Royal School of Mines, Imperial College, London SW7 2AZ, United Kingdom
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21
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Drews M, Büttner J, Bauer M, Ahmed J, Sahu R, Scheu C, Vierrath S, Fischer A, Biro D. Spruce Hard Carbon Anodes for Lithium‐Ion Batteries. ChemElectroChem 2021. [DOI: 10.1002/celc.202101174] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Mathias Drews
- Fraunhofer Institute for Solar Energy Systems, ISE Heidenhofstraße 2 79110 Freiburg Germany
| | - Jan Büttner
- Institute for Inorganic and Analytical Chemistry University of Freiburg Albertstraße 21 79104 Freiburg Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies FIT University of Freiburg Georges-Köhler-Allee 105 79110 Freiburg Germany
- Cluster of Excellence livMatS University of Freiburg 79104 Freiburg Germany
| | - Manuel Bauer
- Fraunhofer Institute for Solar Energy Systems, ISE Heidenhofstraße 2 79110 Freiburg Germany
| | - Junaid Ahmed
- Fraunhofer Institute for Solar Energy Systems, ISE Heidenhofstraße 2 79110 Freiburg Germany
| | - Rajib Sahu
- Max Planck Institute for Iron Research Max-Planck-Straße 1 40237 Düsseldorf Germany
- Materials Analytics RWTH University of Aachen Kopernikusstraße 10 52074 Aachen Germany
| | - Christina Scheu
- Max Planck Institute for Iron Research Max-Planck-Straße 1 40237 Düsseldorf Germany
- Materials Analytics RWTH University of Aachen Kopernikusstraße 10 52074 Aachen Germany
| | - Severin Vierrath
- Freiburg Center for Interactive Materials and Bioinspired Technologies FIT University of Freiburg Georges-Köhler-Allee 105 79110 Freiburg Germany
- Electrochemical Energy Systems IMTEK - Department of Microsystems Engineering University of Freiburg Georges-Köhler-Allee 103 79110 Freiburg Germany
| | - Anna Fischer
- Institute for Inorganic and Analytical Chemistry University of Freiburg Albertstraße 21 79104 Freiburg Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies FIT University of Freiburg Georges-Köhler-Allee 105 79110 Freiburg Germany
- Cluster of Excellence livMatS University of Freiburg 79104 Freiburg Germany
- Freiburg Materials Research Center, FMF University of Freiburg Stefan-Meier-Straße 21 79104 Freiburg Germany
| | - Daniel Biro
- Fraunhofer Institute for Solar Energy Systems, ISE Heidenhofstraße 2 79110 Freiburg Germany
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22
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Drews M, Büttner J, Bauer M, Ahmed J, Sahu R, Scheu C, Vierrath S, Fischer A, Biro D. Cover Feature: Spruce Hard Carbon Anodes for Lithium‐Ion Batteries (ChemElectroChem 24/2021). ChemElectroChem 2021. [DOI: 10.1002/celc.202101500] [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: 11/08/2022]
Affiliation(s)
- Mathias Drews
- Fraunhofer Institute for Solar Energy Systems, ISE Heidenhofstraße 2 79110 Freiburg Germany
| | - Jan Büttner
- Institute for Inorganic and Analytical Chemistry University of Freiburg Albertstraße 21 79104 Freiburg Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies FIT University of Freiburg Georges-Köhler-Allee 105 79110 Freiburg Germany
- Cluster of Excellence livMatS University of Freiburg 79104 Freiburg Germany
| | - Manuel Bauer
- Fraunhofer Institute for Solar Energy Systems, ISE Heidenhofstraße 2 79110 Freiburg Germany
| | - Junaid Ahmed
- Fraunhofer Institute for Solar Energy Systems, ISE Heidenhofstraße 2 79110 Freiburg Germany
| | - Rajib Sahu
- Max Planck Institute for Iron Research Max-Planck-Straße 1 40237 Düsseldorf Germany
- Materials Analytics RWTH University of Aachen Kopernikusstraße 10 52074 Aachen Germany
| | - Christina Scheu
- Max Planck Institute for Iron Research Max-Planck-Straße 1 40237 Düsseldorf Germany
- Materials Analytics RWTH University of Aachen Kopernikusstraße 10 52074 Aachen Germany
| | - Severin Vierrath
- Freiburg Center for Interactive Materials and Bioinspired Technologies FIT University of Freiburg Georges-Köhler-Allee 105 79110 Freiburg Germany
- Electrochemical Energy Systems IMTEK - Department of Microsystems Engineering University of Freiburg Georges-Köhler-Allee 103 79110 Freiburg Germany
| | - Anna Fischer
- Institute for Inorganic and Analytical Chemistry University of Freiburg Albertstraße 21 79104 Freiburg Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies FIT University of Freiburg Georges-Köhler-Allee 105 79110 Freiburg Germany
- Cluster of Excellence livMatS University of Freiburg 79104 Freiburg Germany
- Freiburg Materials Research Center, FMF University of Freiburg Stefan-Meier-Straße 21 79104 Freiburg Germany
| | - Daniel Biro
- Fraunhofer Institute for Solar Energy Systems, ISE Heidenhofstraße 2 79110 Freiburg Germany
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23
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Sahu R, Bogdanovski D, Achenbach JO, Zhang S, Hans M, Primetzhofer D, Schneider JM, Scheu C. Direct MoB MBene domain formation in magnetron sputtered MoAlB thin films. Nanoscale 2021; 13:18077-18083. [PMID: 34726227 DOI: 10.1039/d1nr05712j] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Two-dimensional (2D) inorganic transition metal boride nanosheets are emerging as promising post-graphene materials in energy research due to their unique properties. State-of-the-art processing strategies are based on chemical etching of bulk material synthesized via solid-state reaction at temperatures above 1000 °C. Here, we report the direct formation of MoB MBene domains in a MoAlB thin film by Al deintercalation from MoAlB in the vicinity of AlOx regions. Hence, based on these results a straightforward processing pathway for the direct formation of MoB MBene-AlOx heterostructures without employing chemical etching is proposed here.
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Affiliation(s)
- Rajib Sahu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Dimitri Bogdanovski
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Jan-Ole Achenbach
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Siyuan Zhang
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
| | - Marcus Hans
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Daniel Primetzhofer
- Department of Physics and Astronomy, Uppsala University, Box 516, S-75120 Uppsala, Sweden
| | - Jochen M Schneider
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
- Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf, Germany.
- Materials Analytics, RWTH Aachen University, Kopernikusstr. 10, 52074 Aachen, Germany
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24
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Armengol RA, Lim J, Ledendecker M, Hengge K, Scheu C. Correlation between the TiO 2 encapsulation layer on Pt and its electrochemical behavior. Nanoscale Adv 2021; 3:5075-5082. [PMID: 36132343 PMCID: PMC9417513 DOI: 10.1039/d1na00423a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 07/14/2021] [Indexed: 06/14/2023]
Abstract
Supported metal catalysts with partial encapsulation resulting from strong metal-support interactions show distinctive structural features which strongly affect their functionalities. Yet, challenges in systematic synthesis and in-depth characterization for such systems limit the present understanding of structure-property relationships. Herein, the synthesis and characterization of two Pt/TiO2 models are conducted by a simple change of the synthesis order, while keeping all other parameters constant. They differ in containing either bare or encapsulated Pt nanoparticles. The presence of an extremely thin and inhomogeneous TiO2 layer is clearly demonstrated on 2-3 nm sized Pt nanoparticles by combination of imaging, energy dispersive X-ray spectroscopy and electron energy loss spectroscopy performed in a transmission electron microscope. The two Pt/TiO2 systems exhibit differences in morphology and local structure which can be correlated with their electrochemical activity and stability using cyclic voltammetry experiments. Beyond enhanced particle stability, we report an increase in H+ intercalation on titania and reduced Pt activity due to partial encapsulation by TiO2. Finally, the growth of an encapsulation layer as a result of cyclic voltammetry measurements is discussed. These results shed light on the in-depth structure-property relationship of catalysts with strong metal-support interactions which leads to enhanced functional materials for electrochromic devices and energy applications.
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Affiliation(s)
| | - Joohyun Lim
- Department of Chemistry, Kangwon National University Chuncheon Gangwon 24341 Republic of Korea
| | - Marc Ledendecker
- Department of Technical Chemistry I, Technical University Darmstadt Alarich-Weiss-Straße 8 64287 Germany
| | - Katharina Hengge
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Germany
| | - Christina Scheu
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Germany
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25
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Onur Şahin E, Dai Y, Chan CK, Tüysüz H, Schmidt W, Lim J, Zhang S, Scheu C, Weidenthaler C. Cover Feature: Monitoring the Structure Evolution of Titanium Oxide Photocatalysts: From the Molecular Form via the Amorphous State to the Crystalline Phase (Chem. Eur. J. 45/2021). Chemistry 2021. [DOI: 10.1002/chem.202102280] [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: 11/11/2022]
Affiliation(s)
- Ezgi Onur Şahin
- Heterogeneous Catalysis Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Yitao Dai
- Heterogeneous Catalysis Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Candace K. Chan
- Heterogeneous Catalysis Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
- Materials Science and Engineering School for Engineering of Matter Transport and Energy (SEMTE) Arizona State University AZ 85287-8706 Tempe USA
| | - Harun Tüysüz
- Heterogeneous Catalysis Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Wolfgang Schmidt
- Heterogeneous Catalysis Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Joohyun Lim
- Nanoanalytics and Interfaces Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
- Department of Chemistry Kangwon National University 24341 Chuncheon Republic of Korea
| | - Siyuan Zhang
- Nanoanalytics and Interfaces Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
| | - Christina Scheu
- Nanoanalytics and Interfaces Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
| | - Claudia Weidenthaler
- Heterogeneous Catalysis Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
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26
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Onur Şahin E, Dai Y, Chan CK, Tüysüz H, Schmidt W, Lim J, Zhang S, Scheu C, Weidenthaler C. Monitoring the Structure Evolution of Titanium Oxide Photocatalysts: From the Molecular Form via the Amorphous State to the Crystalline Phase. Chemistry 2021; 27:11600-11608. [PMID: 34060158 PMCID: PMC8456846 DOI: 10.1002/chem.202101117] [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] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Indexed: 11/07/2022]
Abstract
Amorphous Tix Oy with high surface area has attracted significant interest as photocatalyst with higher activity in ultraviolet (UV) light-induced water splitting applications compared to commercial nanocrystalline TiO2 . Under photocatalytic operation conditions, the structure of the molecular titanium alkoxide precursor rearranges upon hydrolysis and leads to higher connectivity of the structure-building units. Structurally ordered domains with sizes smaller than 7 Å form larger aggregates. The experimental scattering data can be explained best with a structure model consisting of an anatase-like core and a distorted shell. Upon exposure to UV light, the white Tix Oy suspension turns dark corresponding to the reduction of Ti4+ to Ti3+ as confirmed by electron energy loss spectroscopy (EELS). Heat-induced crystallisation was followed by in situ temperature-dependent total scattering experiments. First, ordering in the Ti-O environment takes place upon to 350 °C. Above this temperature, the distorted anatase core starts to grow but the structure obtained at 400 °C is still not fully ordered.
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Affiliation(s)
- Ezgi Onur Şahin
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Yitao Dai
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Candace K. Chan
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
- Materials Science and EngineeringSchool for Engineering of MatterTransport and Energy (SEMTE)Arizona State UniversityAZ 85287-8706TempeUSA
| | - Harun Tüysüz
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Wolfgang Schmidt
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Joohyun Lim
- Nanoanalytics and InterfacesMax-Planck-Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
- Department of ChemistryKangwon National University24341ChuncheonRepublic of Korea
| | - Siyuan Zhang
- Nanoanalytics and InterfacesMax-Planck-Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
| | - Christina Scheu
- Nanoanalytics and InterfacesMax-Planck-Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
| | - Claudia Weidenthaler
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
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27
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Frank A, Gänsler T, Hieke S, Fleischmann S, Husmann S, Presser V, Scheu C. Structural and chemical characterization of MoO 2/MoS 2 triple-hybrid materials using electron microscopy in up to three dimensions. Nanoscale Adv 2021; 3:1067-1076. [PMID: 36133289 PMCID: PMC9418330 DOI: 10.1039/d0na00806k] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/24/2020] [Indexed: 06/16/2023]
Abstract
This work presents the synthesis of MoO2/MoS2 core/shell nanoparticles within a carbon nanotube network and their detailed electron microscopy investigation in up to three dimensions. The triple-hybrid core/shell material was prepared by atomic layer deposition of molybdenum oxide onto carbon nanotube networks, followed by annealing in a sulfur-containing gas atmosphere. High-resolution transmission electron microscopy together with electron diffraction, supported by chemical analysis via energy dispersive X-ray and electron energy loss spectroscopy, gave proof of a MoO2 core covered by few layers of a MoS2 shell within an entangled network of carbon nanotubes. To gain further insights into this complex material, the analysis was completed with 3D electron tomography. By using Z-contrast imaging, distinct reconstruction of core and shell material was possible, enabling the analysis of the 3D structure of the material. These investigations showed imperfections in the nanoparticles which can impact material performance, i.e. for faradaic charge storage or electrocatalysis.
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Affiliation(s)
- Anna Frank
- Max-Planck-Institut für Eisenforschung GmbH, Independent Research Group Nanoanalytics and Interfaces Düsseldorf Germany
| | - Thomas Gänsler
- Max-Planck-Institut für Eisenforschung GmbH, Independent Research Group Nanoanalytics and Interfaces Düsseldorf Germany
| | - Stefan Hieke
- Max-Planck-Institut für Eisenforschung GmbH, Independent Research Group Nanoanalytics and Interfaces Düsseldorf Germany
| | | | | | - Volker Presser
- INM - Leibniz Institute for New Materials Saarbrücken Germany
- Department of Materials Science and Engineering, Saarland University Saarbrücken Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Independent Research Group Nanoanalytics and Interfaces Düsseldorf Germany
- Materials Analytics, RWTH Aachen University Aachen Germany
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28
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Onur Şahin E, Tüysüz H, Chan CK, Moon GH, Dai Y, Schmidt W, Lim J, Scheu C, Weidenthaler C. In situ total scattering experiments of nucleation and crystallisation of tantalum-based oxides: from highly dilute solutions via cluster formation to nanoparticles. Nanoscale 2021; 13:150-162. [PMID: 33325940 DOI: 10.1039/d0nr07871a] [Citation(s) in RCA: 3] [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] [Indexed: 06/12/2023]
Abstract
The exact formation mechanism of tantalum oxides (and in general, metal/mixed metal oxides) from alkoxide precursors is still not fully understood, particularly when forming cluster-like or amorphous materials. The structural evolution of Ta-based oxides was studied in detail using X-ray total scattering experiments along with subsequent pair distribution function (PDF) analyses. Starting from a tantalum alkoxide precursor (Ta2(OEt)10), the formation of hydrolysed TaxOyHz clusters in highly diluted aqueous solution was analysed. From the PDF data, the connectivity and arrangement of TaxOy octahedra in the cluster could be deduced as well as the approximate size of the clusters (<1 nm). Construction of cluster models allowed for identification of common structural motifs in the TaxOyHz clusters, ruling out the formation of chain- or ring-like clusters. More likely, bulky clusters with a high number of corner-sharing octahedra are formed. After separation of the amorphous solid from the liquid, temperature-induced crystallisation processes were monitored via in situ total scattering experiments. Between room temperature and 600 °C, only small rearrangements of the amorphous structure are observed. At about 610 °C, amorphous TaxOyHz transforms directly into crystalline orthorhombic L-Ta2O5 without formation of any crystalline intermediate structures.
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Affiliation(s)
- Ezgi Onur Şahin
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany.
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29
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Manjón AG, Löffler T, Meischein M, Meyer H, Lim J, Strotkötter V, Schuhmann W, Ludwig A, Scheu C. Sputter deposition of highly active complex solid solution electrocatalysts into an ionic liquid library: effect of structure and composition on oxygen reduction activity. Nanoscale 2020; 12:23570-23577. [PMID: 33196718 DOI: 10.1039/d0nr07632e] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Complex solid solution electrocatalysts (often called high-entropy alloys) present a new catalyst class with highly promising features due to the interplay of multi-element active sites. One hurdle is the limited knowledge about structure-activity correlations needed for targeted catalyst design. We prepared Cr-Mn-Fe-Co-Ni nanoparticles by magnetron sputtering a high entropy Cantor alloy target simultaneously into an ionic liquid library. The synthesized nanoparticles have a narrow size distribution but different sizes (from 1.3 ± 0.1 nm up to 2.6 ± 0.3 nm), different crystallinity (amorphous, face-centered cubic or body-centered cubic) and composition (i.e. high Mn versus low Mn content). The Cr-Mn-Fe-Co-Ni complex solid solution nanoparticles possess an unprecedented intrinsic electrocatalytic activity for the oxygen reduction reaction in alkaline media, some of them even surpassing that of Pt. The highest intrinsic activity was obtained for body-centered cubic nanoparticles with a low Mn and Fe content which were synthesized using the ionic liquid 1-etyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [Emimi][(Tf)2N].
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Affiliation(s)
- Alba Garzón Manjón
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
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30
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Zhang S, Ahmet I, Kim SH, Kasian O, Mingers AM, Schnell P, Kölbach M, Lim J, Fischer A, Mayrhofer KJJ, Cherevko S, Gault B, van de Krol R, Scheu C. Different Photostability of BiVO 4 in Near-pH-Neutral Electrolytes. ACS Appl Energy Mater 2020; 3:9523-9527. [PMID: 33134878 PMCID: PMC7592387 DOI: 10.1021/acsaem.0c01904] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/02/2020] [Indexed: 05/09/2023]
Abstract
Photoelectrochemical water splitting is a promising route to produce hydrogen from solar energy. However, corrosion of photoelectrodes remains a fundamental challenge for their implementation. Here, we reveal different dissolution behaviors of BiVO4 photoanode in pH-buffered borate, phosphate, and citrate (hole-scavenger) electrolytes, studied in operando employing an illuminated scanning flow cell. We demonstrate that decrease in photocurrents alone does not reflect the degradation of photoelectrodes. Changes in dissolution rates correlate to the evolution of surface chemistry and morphology. The correlative measurements on both sides of the liquid-semiconductor junction provide quantitative comparison and mechanistic insights into the degradation processes.
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Affiliation(s)
- Siyuan Zhang
- Max-Planck-Institut
für Eisenforschung GmbH, 40237 Düsseldorf, Germany
| | - Ibbi Ahmet
- Institute
for Solar Fuels, Helmholtz-Zentrum Berlin
für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Se-Ho Kim
- Max-Planck-Institut
für Eisenforschung GmbH, 40237 Düsseldorf, Germany
| | - Olga Kasian
- Max-Planck-Institut
für Eisenforschung GmbH, 40237 Düsseldorf, Germany
- Helmholtz-Zentrum
Berlin GmbH, Helmholtz Institut Erlangen-Nürnberg, 14109 Berlin, Germany
| | - Andrea M. Mingers
- Max-Planck-Institut
für Eisenforschung GmbH, 40237 Düsseldorf, Germany
| | - Patrick Schnell
- Institute
for Solar Fuels, Helmholtz-Zentrum Berlin
für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Moritz Kölbach
- Max-Planck-Institut
für Eisenforschung GmbH, 40237 Düsseldorf, Germany
| | - Joohyun Lim
- Max-Planck-Institut
für Eisenforschung GmbH, 40237 Düsseldorf, Germany
- Department
of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Anna Fischer
- Institute
of Inorganic and Analytical Chemistry, University
of Freiburg, 79104 Freiburg, Germany
| | - Karl J. J. Mayrhofer
- Helmholtz
Institut Erlangen-Nürnberg for Renewable Energy (IEK-11), Forschungszentrum Jülich, 91058 Erlangen, Germany
| | - Serhiy Cherevko
- Helmholtz
Institut Erlangen-Nürnberg for Renewable Energy (IEK-11), Forschungszentrum Jülich, 91058 Erlangen, Germany
| | - Baptiste Gault
- Max-Planck-Institut
für Eisenforschung GmbH, 40237 Düsseldorf, Germany
- Department
of Materials, Royal School of Mines, Imperial
College London, London, SW7 2AZ, United Kingdom
| | - Roel van de Krol
- Institute
for Solar Fuels, Helmholtz-Zentrum Berlin
für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Christina Scheu
- Max-Planck-Institut
für Eisenforschung GmbH, 40237 Düsseldorf, Germany
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31
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Hoque MA, Gil-Sepulcre M, de Aguirre A, Elemans JAAW, Moonshiram D, Matheu R, Shi Y, Benet-Buchholz J, Sala X, Malfois M, Solano E, Lim J, Garzón-Manjón A, Scheu C, Lanza M, Maseras F, Gimbert-Suriñach C, Llobet A. Water oxidation electrocatalysis using ruthenium coordination oligomers adsorbed on multiwalled carbon nanotubes. Nat Chem 2020; 12:1060-1066. [PMID: 32989272 DOI: 10.1038/s41557-020-0548-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 08/04/2020] [Indexed: 12/27/2022]
Abstract
Photoelectrochemical cells that utilize water as a source of electrons are one of the most attractive solutions for the replacement of fossil fuels by clean and sustainable solar fuels. To achieve this, heterogeneous water oxidation catalysis needs to be mastered and properly understood. The search continues for a catalyst that is stable at the surface of electro(photo)anodes and can efficiently perform this reaction at the desired neutral pH. Here, we show how oligomeric Ru complexes can be anchored on the surfaces of graphitic materials through CH-π interactions between the auxiliary ligands bonded to Ru and the hexagonal rings of the graphitic surfaces, providing control of their molecular coverage. These hybrid molecular materials behave as molecular electroanodes that catalyse water oxidation to dioxygen at pH 7 with high current densities. This strategy for the anchoring of molecular catalysts on graphitic surfaces can potentially be extended to other transition metals and other catalytic reactions.
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Affiliation(s)
- Md Asmaul Hoque
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology (BIST), Tarragona, Spain
| | - Marcos Gil-Sepulcre
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology (BIST), Tarragona, Spain
| | - Adiran de Aguirre
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology (BIST), Tarragona, Spain
| | | | - Dooshaye Moonshiram
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Madrid, Spain
| | - Roc Matheu
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology (BIST), Tarragona, Spain
| | - Yuanyuan Shi
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology (BIST), Tarragona, Spain.,Institute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nanoscience and Technology, Suzhou, China
| | - Jordi Benet-Buchholz
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology (BIST), Tarragona, Spain
| | - Xavier Sala
- Departament de Química, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Marc Malfois
- NCD-SWEET beamline, ALBA synchrotron light source, Barcelona, Spain
| | - Eduardo Solano
- NCD-SWEET beamline, ALBA synchrotron light source, Barcelona, Spain
| | - Joohyun Lim
- Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany
| | | | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany
| | - Mario Lanza
- Institute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nanoscience and Technology, Suzhou, China.
| | - Feliu Maseras
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology (BIST), Tarragona, Spain. .,Departament de Química, Universitat Autonoma de Barcelona, Barcelona, Spain.
| | - Carolina Gimbert-Suriñach
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology (BIST), Tarragona, Spain.
| | - Antoni Llobet
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology (BIST), Tarragona, Spain. .,Departament de Química, Universitat Autonoma de Barcelona, Barcelona, Spain.
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32
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Silva GC, Venturini SI, Zhang S, Löffler M, Scheu C, Mayrhofer KJJ, Ticianelli EA, Cherevko S. Oxygen Evolution Reaction on Tin Oxides Supported Iridium Catalysts: Do We Need Dopants? ChemElectroChem 2020. [DOI: 10.1002/celc.202000391] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Gabriel C. Silva
- Helmholtz-Institute Erlangen-Nürnberg for Renewable Energy (IEK-11) Forschungszentrum Jülich GmbH Egerlandstr. 3 91058 Erlangen Germany
- São Carlos Institute of Chemistry University of São Paulo Av. Trabalhador São-carlense 400 13560-970 São Carlos Brazil
- Federal Institute of Southeastern of Minas Gerais Rua Monsenhor José Augusto 204 36205-018 Barbacena Brazil
| | - Seiti I. Venturini
- São Carlos Institute of Chemistry University of São Paulo Av. Trabalhador São-carlense 400 13560-970 São Carlos Brazil
| | - Siyuan Zhang
- Independent Research Group Nanoanalytics and Interfaces Max-Planck-Institut für Eisenforschung GmbH 40237 Düsseldorf Germany
| | - Mario Löffler
- Helmholtz-Institute Erlangen-Nürnberg for Renewable Energy (IEK-11) Forschungszentrum Jülich GmbH Egerlandstr. 3 91058 Erlangen Germany
- Department of Chemical and Biological Engineering Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstr. 3 91058 Erlangen Germany
| | - Christina Scheu
- Independent Research Group Nanoanalytics and Interfaces Max-Planck-Institut für Eisenforschung GmbH 40237 Düsseldorf Germany
| | - Karl J. J. Mayrhofer
- Helmholtz-Institute Erlangen-Nürnberg for Renewable Energy (IEK-11) Forschungszentrum Jülich GmbH Egerlandstr. 3 91058 Erlangen Germany
- Department of Chemical and Biological Engineering Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstr. 3 91058 Erlangen Germany
| | - Edson A. Ticianelli
- São Carlos Institute of Chemistry University of São Paulo Av. Trabalhador São-carlense 400 13560-970 São Carlos Brazil
| | - Serhiy Cherevko
- Helmholtz-Institute Erlangen-Nürnberg for Renewable Energy (IEK-11) Forschungszentrum Jülich GmbH Egerlandstr. 3 91058 Erlangen Germany
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33
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Ebenhoch C, Kalb J, Lim J, Seewald T, Scheu C, Schmidt-Mende L. Hydrothermally Grown TiO 2 Nanorod Array Memristors with Volatile States. ACS Appl Mater Interfaces 2020; 12:23363-23369. [PMID: 32321245 DOI: 10.1021/acsami.0c05164] [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: 06/11/2023]
Abstract
In the present study, the memristive characteristics of hydrothermally grown TiO2 nanorod arrays, particularly, the difference in the retention time of the resistance state, are investigated in dependence of the array growth temperature. A volatile behavior is observed and related to a redistribution of oxygen vacancies over time. It is shown that the retention time increases for increasing array growth temperatures from several seconds up to 20 min. The relaxation behavior is also seen in the current-voltage characteristics, which do not show the common unipolar, bipolar, or complementary switching behavior. Instead, the temporal evolution depends on the duration of the applied voltage and on the nanowire growth temperature. Therefore, electronic measurements are combined with scanning electron and scanning transmission electron microscopy, so that the amount of oxygen defect-rich grain boundaries in the upper part of the nanowires can be linked to the differences in the current-voltage behavior and retention time.
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Affiliation(s)
- Carola Ebenhoch
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - Julian Kalb
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - Joohyun Lim
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Tobias Seewald
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
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34
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Lim J, Kasiri G, Sahu R, Schweinar K, Hengge K, Raabe D, La Mantia F, Scheu C. Frontispiece: Irreversible Structural Changes of Copper Hexacyanoferrate Used as a Cathode in Zn‐Ion Batteries. Chemistry 2020. [DOI: 10.1002/chem.202082263] [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: 11/11/2022]
Affiliation(s)
- Joohyun Lim
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
| | - Ghoncheh Kasiri
- Universität Bremen, Energiespeicher- und Energiewandlersysteme Bibliothekstr. 1 28359 Bremen Germany
| | - Rajib Sahu
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
| | - Kevin Schweinar
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
| | - Katharina Hengge
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
| | - Dierk Raabe
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
| | - Fabio La Mantia
- Universität Bremen, Energiespeicher- und Energiewandlersysteme Bibliothekstr. 1 28359 Bremen Germany
| | - Christina Scheu
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
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35
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Kampmann J, Betzler S, Hajiyani H, Häringer S, Beetz M, Harzer T, Kraus J, Lotsch BV, Scheu C, Pentcheva R, Fattakhova-Rohlfing D, Bein T. How photocorrosion can trick you: a detailed study on low-bandgap Li doped CuO photocathodes for solar hydrogen production. Nanoscale 2020; 12:7766-7775. [PMID: 32215409 DOI: 10.1039/c9nr10250g] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The efficiency of photoelectrochemical tandem cells is still limited by the availability of stable low band gap electrodes. In this work, we report a photocathode based on lithium doped copper(ii) oxide, a black p-type semiconductor. Density functional theory calculations with a Hubbard U term show that low concentrations of Li (Li0.03Cu0.97O) lead to an upward shift of the valence band maximum that crosses the Fermi level and results in a p-type semiconductor. Therefore, Li doping emerged as a suitable approach to manipulate the electronic structure of copper oxide based photocathodes. As this material class suffers from instability in water under operating conditions, the recorded photocurrents are repeatedly misinterpreted as hydrogen evolution evidence. We investigated the photocorrosion behavior of LixCu1-xO cathodes in detail and give the first mechanistic study of the fundamental physical process. The reduced copper oxide species were localized by electron energy loss spectroscopy mapping. Cu2O grows as distinct crystallites on the surface of LixCu1-xO instead of forming a dense layer. Additionally, there is no obvious Cu2O gradient inside the films, as Cu2O seems to form on all LixCu1-xO nanocrystals exposed to water. The application of a thin Ti0.8Nb0.2Ox coating by atomic layer deposition and the deposition of a platinum co-catalyst increased the stability of LixCu1-xO against decomposition. These devices showed a stable hydrogen evolution for 15 minutes.
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Affiliation(s)
- Jonathan Kampmann
- Department of Chemistry and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Butenandtstr. 5-13 (E), 81377 Munich, Germany.
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36
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Lim J, Kim S, Aymerich Armengol R, Kasian O, Choi P, Stephenson LT, Gault B, Scheu C. Atomic-Scale Mapping of Impurities in Partially Reduced Hollow TiO 2 Nanowires. Angew Chem Int Ed Engl 2020; 59:5651-5655. [PMID: 31922307 PMCID: PMC7155045 DOI: 10.1002/anie.201915709] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Indexed: 11/05/2022]
Abstract
The incorporation of impurities during the chemical synthesis of nanomaterials is usually uncontrolled and rarely reported because of the formidable challenge in measuring trace amounts of often light elements with sub-nanometer spatial resolution. And yet, these foreign elements (introduced by doping, for example) influence functional properties. We demonstrate how the hydrothermal growth and a partial reduction reaction on hollow TiO2 nanowires leads to the introduction of parts per millions of boron, sodium, and nitrogen. This doping explains the presence of oxygen vacancies and reduced Ti states at the surface, which enhance the functional properties of TiO2 . Our results were obtained on model metal oxide nanomaterials and they shed light on a general process that leads to the uncontrolled incorporation of trace impurities in TiO2 , thereby, having a strong effect on applications in energy-harvesting.
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Affiliation(s)
- Joohyun Lim
- Max-Planck Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
| | - Se‐Ho Kim
- Max-Planck Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
| | | | - Olga Kasian
- Max-Planck Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
- Helmholtz-Zentrum BerlinHelmholtz-Institute Erlangen-Nürnberg14109BerlinGermany
| | - Pyuck‐Pa Choi
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak-roYuseong-guDaejeon34141Republic of Korea
| | - Leigh T. Stephenson
- Max-Planck Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
| | - Baptiste Gault
- Max-Planck Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
- Department of MaterialsRoyal School of MinesImperial CollegeLondonSW7 2AZUK
| | - Christina Scheu
- Max-Planck Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
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37
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Lim J, Kim S, Aymerich Armengol R, Kasian O, Choi P, Stephenson LT, Gault B, Scheu C. Atomic‐Scale Mapping of Impurities in Partially Reduced Hollow TiO
2
Nanowires. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201915709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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)
- Joohyun Lim
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
| | - Se‐Ho Kim
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
| | | | - Olga Kasian
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
- Helmholtz-Zentrum Berlin Helmholtz-Institute Erlangen-Nürnberg 14109 Berlin Germany
| | - Pyuck‐Pa Choi
- Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro Yuseong-gu Daejeon 34141 Republic of Korea
| | - Leigh T. Stephenson
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
| | - Baptiste Gault
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
- Department of Materials Royal School of Mines Imperial College London SW7 2AZ UK
| | - Christina Scheu
- Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 1 40237 Düsseldorf Germany
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38
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Lim J, Kasiri G, Sahu R, Schweinar K, Hengge K, Raabe D, La Mantia F, Scheu C. Irreversible Structural Changes of Copper Hexacyanoferrate Used as a Cathode in Zn-Ion Batteries. Chemistry 2020; 26:4917-4922. [PMID: 31782839 PMCID: PMC7187350 DOI: 10.1002/chem.201905384] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Indexed: 11/09/2022]
Abstract
The structural changes of copper hexacyanoferrate (CuHCF), a Prussian blue analogue, which occur when used as a cathode in an aqueous Zn-ion battery, are investigated using electron microscopy techniques. The evolution of Znx Cu1-x HCF phases possessing wire and cubic morphologies from initial CuHCF nanoparticles are monitored after hundreds of cycles. Irreversible introduction of Zn ions to CuHCF is revealed locally using scanning transmission electron microscopy. A substitution mechanism is proposed to explain the increasing Zn content within the cathode material while simultaneously the Cu content is lowered during Zn-ion battery cycling. The present study demonstrates that the irreversible introduction of Zn ions is responsible for the decreasing Zn ion capacity of the CuHCF cathode in high electrolyte concentration.
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Affiliation(s)
- Joohyun Lim
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Ghoncheh Kasiri
- Universität Bremen, Energiespeicher- und Energiewandlersysteme, Bibliothekstr. 1, 28359, Bremen, Germany
| | - Rajib Sahu
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Kevin Schweinar
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Katharina Hengge
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Dierk Raabe
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Fabio La Mantia
- Universität Bremen, Energiespeicher- und Energiewandlersysteme, Bibliothekstr. 1, 28359, Bremen, Germany
| | - Christina Scheu
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
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Yang F, Schröck C, Kugelstadt J, Zhang S, Scheu C, Trautmann C, Maijenburg AW, Toimil-Molares ME. Cu 2O/TiO 2 Nanowire Assemblies as Photocathodes for Solar Hydrogen Evolution: Influence of Diameter, Length and NumberDensity of Wires. Z PHYS CHEM 2020. [DOI: 10.1515/zpch-2019-1529] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The performance of free-standing parallel-aligned nanowire arrays and interconnected networks of single-crystalline cuprous oxide (Cu2O) coated with titanium oxide (TiO2) as photocathodes for solar energy harvesting was analyzed. The nanostructures were synthesized by electrodeposition in polymer membranes prepared by ion-track technology. To enhance the photoelectrochemical stability of the nanowires in aqueous solution, they were conformally coated with a 10 nm thick TiO2 layer by atomic layer deposition. The diameter, size, geometry and number density of the parallel nanowires were systematically varied. The generated photocurrents show a clear increase as a function of wire diameter and wire number. In turn, the photocurrent does not get larger with increasing wire length. Highly interconnected networks of nanowires under 45° from various directions enabled further increase of wire density number and exhibited higher photocurrent densities compared to parallel arrays.
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Affiliation(s)
- Florent Yang
- GSI Helmholtzzentrum für Schwerionenforschung GmbH , Materials Research , Planckstraße 1 , 64291 Darmstadt , Germany
| | - Christopher Schröck
- GSI Helmholtzzentrum für Schwerionenforschung GmbH , Materials Research , Planckstraße 1 , 64291 Darmstadt , Germany
- Technische Universität Darmstadt , Alarich-Weiss-Straße 2 , 64287 Darmstadt , Germany
| | - Jan Kugelstadt
- GSI Helmholtzzentrum für Schwerionenforschung GmbH , Materials Research , Planckstraße 1 , 64291 Darmstadt , Germany
- Hochschule RheinMain , Am Brückweg 26 , 65428 Rüsselsheim , Germany
| | - Siyuan Zhang
- Max-Planck-Institut für Eisenforschung GmbH , Max-Planck-Str. 1 , 40237 Düsseldorf , Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH , Max-Planck-Str. 1 , 40237 Düsseldorf , Germany
| | - Christina Trautmann
- GSI Helmholtzzentrum für Schwerionenforschung GmbH , Materials Research , Planckstraße 1 , 64291 Darmstadt , Germany
- Technische Universität Darmstadt , Alarich-Weiss-Straße 2 , 64287 Darmstadt , Germany
| | - A. Wouter Maijenburg
- GSI Helmholtzzentrum für Schwerionenforschung GmbH , Materials Research , Planckstraße 1 , 64291 Darmstadt , Germany
| | - Maria Eugenia Toimil-Molares
- GSI Helmholtzzentrum für Schwerionenforschung GmbH , Materials Research , Planckstraße 1 , 64291 Darmstadt , Germany
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Kim SH, Lim J, Sahu R, Kasian O, Stephenson LT, Scheu C, Gault B. Direct Imaging of Dopant and Impurity Distributions in 2D MoS 2. Adv Mater 2020; 32:e1907235. [PMID: 31930769 DOI: 10.1002/adma.201907235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/12/2019] [Indexed: 06/10/2023]
Abstract
Molybdenum disulfide (MoS2 ) nanosheet is a two-dimensional (2D) material with high electron mobility and with high potential for applications in catalysis and electronics. MoS2 nanosheets are synthesized using a one-pot wet-chemical synthesis route with and without Re doping. Atom probe tomography reveals that 3.8 at% Re is homogeneously distributed within the Re-doped sheets. Other impurities are also found integrated within the material: light elements including C, N, O, and Na, locally enriched up to 0.1 at%, as well as heavy elements such as V and W. Analysis of the nondoped sample reveals that the W and V likely originate from the Mo precursor. It is shown how wet-chemical synthesis results in an uncontrolled integration of species from the solution that can affect the material's activity. The results of this work are expected to contribute to an improved understanding of the relationships linking composition to properties of 2D transition-metal dichalcogenide materials.
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Affiliation(s)
- Se-Ho Kim
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf, 40237, Germany
| | - Joohyun Lim
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf, 40237, Germany
| | - Rajib Sahu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf, 40237, Germany
| | - Olga Kasian
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf, 40237, Germany
- Helmholtz-Zentrum Berlin GmbH, Helmholtz-Institute Erlangen-Nürnberg, Berlin, 14109, Germany
| | - Leigh T Stephenson
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf, 40237, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf, 40237, Germany
| | - Baptiste Gault
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf, 40237, Germany
- Department of Materials, Royal School of Mines, Imperial College, Prince Consort Road, London, SW7 2BP, UK
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Schmitz A, Meyer H, Meischein M, Garzón Manjón A, Schmolke L, Giesen B, Schlüsener C, Simon P, Grin Y, Fischer RA, Scheu C, Ludwig A, Janiak C. Synthesis of plasmonic Fe/Al nanoparticles in ionic liquids. RSC Adv 2020; 10:12891-12899. [PMID: 35492117 PMCID: PMC9051251 DOI: 10.1039/d0ra01111h] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [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: 02/05/2020] [Accepted: 03/19/2020] [Indexed: 12/12/2022] Open
Abstract
Bottom-up and top-down approaches are described for the challenging synthesis of Fe/Al nanoparticles (NPs) in ionic liquids (ILs) under mild conditions. The crystalline phase and morphology of the metal nanoparticles synthesized in three different ionic liquids were identified by powder X-ray diffractometry (PXRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), selected-area electron diffraction (SAED) and fast Fourier transform (FFT) of high-resolution TEM images. Characterization was completed by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) for the analysis of the element composition of the whole sample consisting of the NPs and the amorphous background. The bottom-up approaches resulted in crystalline FeAl NPs on an amorphous background. The top-down approach revealed small NPs and could be identified as Fe4Al13 NPs which in the IL [OPy][NTf2] yield two absorption bands in the green-blue to green spectral region at 475 and 520 nm which give rise to a complementary red color, akin to appropriate Au NPs. Fe/Al NPs of the right size mimic with their red color the electronic surface structure of Au NPs.![]()
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Podjaski F, Weber D, Zhang S, Diehl L, Eger R, Duppel V, Alarcón-Lladó E, Richter G, Haase F, Fontcuberta i Morral A, Scheu C, Lotsch BV. Rational strain engineering in delafossite oxides for highly efficient hydrogen evolution catalysis in acidic media. Nat Catal 2019. [DOI: 10.1038/s41929-019-0400-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [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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Lukic S, Busser GW, Zhang S, Menze J, Muhler M, Scheu C, Winterer M. Nanocrystalline Ga–Zn Oxynitride Materials: Minimized Defect Density for Improved Photocatalytic Activity? Z PHYS CHEM 2019. [DOI: 10.1515/zpch-2019-1432] [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: 11/15/2022]
Abstract
Abstract
We present an alternative synthesis strategy for developing nanocrystalline (Ga1−xZnx)(N1−xOx) semiconductors known to be very efficient photoabsorbers. In a first step we produce mixtures of highly crystalline β-Ga2O3 and wurtzite-type ZnO nanoparticles by chemical vapor synthesis. (Ga1−xZnx)(N1−xOx) nanoparticles of wurtzite structure are then formed by reaction of these precursor materials with ammonia. Microstructure as well as composition (zinc loss) changes with nitridation time: band gap energy, crystallite size and crystallinity increase, while defect density decreases with increasing nitridation time. Crystallite growth results in a corresponding decrease in specific surface area. In the UV regime photocatalytic activity for overall water splitting can be monitored for samples both before and after nitridation. We find a significantly lower photocatalytic activity in the nitrided samples, even though the crystallinity is significantly higher and the defect density is significantly lower after nitridation. Both properties should have led to a lower probability for charge carrier recombination, and, consequently, to a higher photocatalytic activity.
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Affiliation(s)
- Sasa Lukic
- Nanoparticle Process Technology (NPPT) and Center for Nanointegration Duisburg-Essen (CENIDE) , University of Duisburg-Essen , 47057 Duisburg , Germany
| | | | - Siyuan Zhang
- Max-Planck-Institut für Eisenforschung GmbH , 40237 Düsseldorf , Germany
| | - Jasper Menze
- Laboratory of Industrial Chemistry , Ruhr-University Bochum , 44780 Bochum , Germany
| | - Martin Muhler
- Laboratory of Industrial Chemistry , Ruhr-University Bochum , 44780 Bochum , Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH , 40237 Düsseldorf , Germany
| | - Markus Winterer
- Nanoparticle Process Technology (NPPT) and Center for Nanointegration Duisburg-Essen (CENIDE) , University of Duisburg-Essen , 47057 Duisburg , Germany
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Giesen B, Nickel AC, Garzón Manjón A, Vargas Toscano A, Scheu C, Kahlert UD, Janiak C. Influence of synthesis methods on the internalization of fluorescent gold nanoparticles into glioblastoma stem-like cells. J Inorg Biochem 2019; 203:110952. [PMID: 31794896 DOI: 10.1016/j.jinorgbio.2019.110952] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 09/17/2019] [Revised: 11/14/2019] [Accepted: 11/22/2019] [Indexed: 10/25/2022]
Abstract
Glioblastoma (GBM) is an aggressive disease with currently no satisfying treatment option available. GBM cells with stem cell properties are thought to be responsible for the initiation and propagation of the disease, as well as main contributors to the emergence of therapy resistance. In this work, we developed a novel method to synthesize fluorescent gold nanoparticles as potential drug and gene delivery systems for GBM therapy, able to penetrate three-dimensional stem cell selected patient-derived GBM neurosphere systems in vitro. By using polyethylene imine (PEI) as a stabilizer and reducing agent, as well as fluorescein isothiocyanate (FITC) as a fluorescent marker, our fully in-house developed fluorescent gold nanoparticles (AuPEI-FITC NPs) with core sizes between 3 and 6 nm were obtained via a fast microwave-assisted reaction. Cytotoxicity, adsorption and internalization of AuPEI-FITC NPs into the cell lines JHH520, 407 and GBM1 were investigated using the cellular growth assay and fluorescence-activated cell sorting (FACS) analysis. AuPEI-FITC NPs showed no apparent cytotoxicity and an uptake in cells of up to ~80%. A differentiation between surface-bound and internalized AuPEI-FITC NPs was possible by quenching extracellular signals. This resulted in a maximal internalization degree of 61%, which depends highly on the synthesis method of the nanoparticles and the cell type tested. The best internalization was found for AuPEI-FITC1 which was prepared in a one pot reaction from KAuCl4, PEI and FITC. Thus, appropriately synthesized AuPEI-FITC NPs show great potential as vehicles to transport DNA or drugs in GBM cells.
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Affiliation(s)
- Beatriz Giesen
- Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine-Universität Düsseldorf, 40204 Düsseldorf, Germany
| | - Ann-Christin Nickel
- Klinik für Neurochirurgie, Universitätsklinikum Düsseldorf, 40225 Düsseldorf, Germany
| | - Alba Garzón Manjón
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Andrés Vargas Toscano
- Klinik für Neurochirurgie, Universitätsklinikum Düsseldorf, 40225 Düsseldorf, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Ulf Dietrich Kahlert
- Klinik für Neurochirurgie, Universitätsklinikum Düsseldorf, 40225 Düsseldorf, Germany; Deutsches Konsortium für Translationale Krebsforschung (DKTK), Essen/Düsseldorf, Germany.
| | - Christoph Janiak
- Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine-Universität Düsseldorf, 40204 Düsseldorf, Germany.
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Abuayyash A, Ziegler N, Meyer H, Meischein M, Sengstock C, Moellenhoff J, Rurainsky C, Heggen M, Garzón-Manjón A, Scheu C, Tschulik K, Ludwig A, Köller M. Enhanced antibacterial performance of ultrathin silver/platinum nanopatches by a sacrificial anode mechanism. Nanomedicine 2019; 24:102126. [PMID: 31734515 DOI: 10.1016/j.nano.2019.102126] [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: 02/11/2019] [Revised: 11/06/2019] [Accepted: 11/07/2019] [Indexed: 11/15/2022]
Abstract
The development of antibacterial implant surfaces is a challenging task in biomaterial research. We fabricated a highly antibacterial bimetallic platinum (Pt)/silver(Ag) nanopatch surface by short time sputtering of Pt and Ag on titanium. The sputter process led to a patch-like distribution with crystalline areas in the nanometer-size range (1.3-3.9 nm thickness, 3-60 nm extension). Structural analyses of Pt/Ag samples showed Ag- and Pt-rich areas containing nanoparticle-like Pt deposits of 1-2 nm. The adhesion and proliferation properties of S. aureus on the nanopatch samples were analyzed. Consecutively sputtered Ag/Pt nanopatches (Pt followed by Ag) induced enhanced antimicrobial activity compared to co-sputtered Pt/Ag samples or pure Ag patches of similar Ag amounts. The underlying sacrificial anode mechanism was proved by linear sweep voltammetry. The advantages of this nanopatch coating are the enhanced antimicrobial activity despite a reduced total amount of Ag/Pt and a self-limited effect due the rapid Ag dissolution.
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Affiliation(s)
- Adham Abuayyash
- BG University Hospital Bergmannsheil, Surgical Research, Bochum, Germany
| | - Nadine Ziegler
- Ruhr University Bochum, Institute for Materials, Faculty of Mechanical Engineering, Bochum, Germany
| | - Hajo Meyer
- Ruhr University Bochum, Institute for Materials, Faculty of Mechanical Engineering, Bochum, Germany
| | - Michael Meischein
- Ruhr University Bochum, Institute for Materials, Faculty of Mechanical Engineering, Bochum, Germany
| | | | - Julian Moellenhoff
- BG University Hospital Bergmannsheil, Surgical Research, Bochum, Germany
| | - Christian Rurainsky
- Ruhr University Bochum, Faculty for Chemistry and Biochemistry, Analytical Chemistry II, Bochum, Germany
| | - Marc Heggen
- Forschungszentrum Jülich, Ernst Ruska-Center for Microscopy and Spectroscopy with Electrons, Jülich, Germany
| | | | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany
| | - Kristina Tschulik
- Ruhr University Bochum, Faculty for Chemistry and Biochemistry, Analytical Chemistry II, Bochum, Germany
| | - Alfred Ludwig
- Ruhr University Bochum, Institute for Materials, Faculty of Mechanical Engineering, Bochum, Germany
| | - Manfred Köller
- BG University Hospital Bergmannsheil, Surgical Research, Bochum, Germany.
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Meischein M, Garzón-Manjón A, Frohn T, Meyer H, Salomon S, Scheu C, Ludwig A. Combinatorial Synthesis of Binary Nanoparticles in Ionic Liquids by Cosputtering and Mixing of Elemental Nanoparticles. ACS Comb Sci 2019; 21:743-752. [PMID: 31614084 DOI: 10.1021/acscombsci.9b00140] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Binary alloy nanoparticles were fabricated by two combinatorial methods: (I) cosputtering from elemental targets into the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [Bmim][(Tf)2N] and (II) by mixing elemental nanoparticles after sputtering them separately into [Bmim][(Tf)2N]. Both methods lead to the formation of Au-Cu nanoparticles (2.3 nm for cosputtered, 3.6 nm for mixed), however with different resulting compositions: cosputtered nanoparticles show a composition range of Au80-90Cu20-10; mixing of Au- and Cu-loaded ionic liquids leads to the formation of Au75Cu25 nanoparticles. Annealing the binary nanoparticles at 100 °C shows that the mixed nanoparticles grow to sizes of 4.1 nm, whereas the cosputtered nanoparticles grow only to 3 nm.
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Affiliation(s)
- Michael Meischein
- Chair for Materials Discovery and Interfaces, Institute for Materials, Faculty of Mechanical Engineering, Ruhr University Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
| | - Alba Garzón-Manjón
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237 Düsseldorf, Germany
| | - Thomas Frohn
- Chair for Materials Discovery and Interfaces, Institute for Materials, Faculty of Mechanical Engineering, Ruhr University Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
| | - Hajo Meyer
- Chair for Materials Discovery and Interfaces, Institute for Materials, Faculty of Mechanical Engineering, Ruhr University Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
| | - Steffen Salomon
- Chair for Materials Discovery and Interfaces, Institute for Materials, Faculty of Mechanical Engineering, Ruhr University Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237 Düsseldorf, Germany
| | - Alfred Ludwig
- Chair for Materials Discovery and Interfaces, Institute for Materials, Faculty of Mechanical Engineering, Ruhr University Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
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47
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Zhang S, Hajiyani H, Hufnagel AG, Kampmann J, Breitbach B, Bein T, Fattakhova-Rohlfing D, Pentcheva R, Scheu C. Sn-Doped Hematite for Photoelectrochemical Water Splitting: The Effect of Sn Concentration. Z PHYS CHEM 2019. [DOI: 10.1515/zpch-2019-1482] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Hematite-based photoanodes have been intensively studied for photoelectrochemical water oxidation. The n-type dopant Sn has been shown to benefit the activity of hematite anodes. We demonstrate in this study that Sn-doped hematite thin films grown by atomic layer deposition can achieve uniform doping across the film thickness up to at least 32 mol%, far exceeding the equilibrium solubility limit of less than 1 mol%. On the other hand, with the introduction of Sn doping, the hematite crystallite size decreases and many twin boundaries form in the film, which may contribute to the low photocurrent observed in these films. Density functional theory calculations with a Hubbard U term show that Sn doping has multiple effects on the hematite properties. With increasing Sn4+ content, the Fe2+ concentration increases, leading to a reduction of the band gap and finally to a metallic state. This goes hand in hand with an increase of the lattice constant.
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Affiliation(s)
- Siyuan Zhang
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1 , 40237 Düsseldorf , Germany
| | - Hamidreza Hajiyani
- Department of Physics and Center for Nanointegration Duisburg-Essen (CENIDE) , Universität Duisburg-Essen , Lotharstraße 1 , 47057 Duisburg , Germany
| | - Alexander G. Hufnagel
- Department of Chemistry and Center for NanoScience (CeNS) , University of Munich (LMU) , Butenandtstraße 5-13 (E) , 81377 Munich , Germany
| | - Jonathan Kampmann
- Department of Chemistry and Center for NanoScience (CeNS) , University of Munich (LMU) , Butenandtstraße 5-13 (E) , 81377 Munich , Germany
| | - Benjamin Breitbach
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1 , 40237 Düsseldorf , Germany
| | - Thomas Bein
- Department of Chemistry and Center for NanoScience (CeNS) , University of Munich (LMU) , Butenandtstraße 5-13 (E) , 81377 Munich , Germany
| | - Dina Fattakhova-Rohlfing
- Institute of Energy and Climate Research (IEK-1), Forschungszentrum Jülich GmbH , Wilhelm-Johnen-Straße , 52425 Jülich , Germany
- Faculty of Engineering and Center for Nanointegration Duisburg-Essen (CENIDE), Universität Duisburg-Essen , Lotharstraße 1 , 47057 Duisburg , Germany
| | - Rossitza Pentcheva
- Department of Physics and Center for Nanointegration Duisburg-Essen (CENIDE) , Universität Duisburg-Essen , Lotharstraße 1 , 47057 Duisburg , Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1 , 40237 Düsseldorf , Germany
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Abstract
Abstract
Chemical surface segregation is a design variable in the optimization of phocathodes but has largely been investigated through surface passivation or decoration. In this study a long charge carrier lifetime material, Al–Cr–Fe–O, exhibiting strong photocurrent recombination is investigated for its atomic scale crystallographic and chemical inhomogeneity. Combined scanning transmission electron microscopy and atom probe tomography unveils that insulating Al- and Cr-rich surface layers form during processing. These are discussed to be the primary reason for experimentally observed charge carrier recombination. This study highlights the importance of processing in the design, discovery and optimization of new light absorber materials for photoelectrochemical water splitting.
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Affiliation(s)
- Helge S. Stein
- Chair for Materials Discovery and Interfaces, Institute for Materials, Ruhr-Universität Bochum , Universitätsstr. 150, 44801 Bochum , Germany
| | - Siyuan Zhang
- Max-Planck Institut für Eisenforschung , Max-Planck Str. 1, 40237 Düsseldorf , Germany
| | - Yujiao Li
- ZGH, Ruhr-Universität Bochum , Universitätsstr. 150, 44801 Bochum , Germany
| | - Christina Scheu
- Max-Planck Institut für Eisenforschung , Max-Planck Str. 1, 40237 Düsseldorf , Germany
- RWTH Aachen, Materials Analytics, RWTH Aachen University , Kopernikusstr. 10, 52074 Aachen , Germany
| | - Alfred Ludwig
- Chair for Materials Discovery and Interfaces, Institute for Materials, Ruhr-Universität Bochum , Universitätsstr. 150, 44801 Bochum , Germany
- ZGH, Ruhr-Universität Bochum , Universitätsstr. 150, 44801 Bochum , Germany
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49
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Burratti L, Ciotta E, Bolli E, Kaciulis S, Casalboni M, De Matteis F, Garzón-Manjón A, Scheu C, Pizzoferrato R, Prosposito P. Fluorescence enhancement induced by the interaction of silver nanoclusters with lead ions in water. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.123634] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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50
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Stelzer B, Chen X, Bliem P, Hans M, Völker B, Sahu R, Scheu C, Primetzhofer D, Schneider JM. Remote Tracking of Phase Changes in Cr 2AlC Thin Films by In-situ Resistivity Measurements. Sci Rep 2019; 9:8266. [PMID: 31164687 PMCID: PMC6547878 DOI: 10.1038/s41598-019-44692-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [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: 02/25/2019] [Accepted: 05/17/2019] [Indexed: 11/09/2022] Open
Abstract
Resistivity changes of magnetron sputtered, amorphous Cr2AlC thin films were measured during heating in vacuum. Based on correlative X-ray diffraction, in-situ and ex-situ selected area electron diffraction measurements and differential scanning calorimetry data from literature it is evident that the resistivity changes at 552 ± 4 and 585 ± 13 °C indicate the phase transitions from amorphous to a hexagonal disordered solid solution structure and from the latter to MAX phase, respectively. We have shown that phase changes in Cr2AlC thin films can be revealed by in-situ measurements of thermally induced resistivity changes.
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Affiliation(s)
- Bastian Stelzer
- Materials Chemistry, RWTH Aachen University, D-52074, Aachen, Germany.
| | - Xiang Chen
- Materials Chemistry, RWTH Aachen University, D-52074, Aachen, Germany
| | - Pascal Bliem
- Materials Chemistry, RWTH Aachen University, D-52074, Aachen, Germany
| | - Marcus Hans
- Materials Chemistry, RWTH Aachen University, D-52074, Aachen, Germany
| | - Bernhard Völker
- Max-Planck-Institut für Eisenforschung GmbH, D-40237, Düsseldorf, Germany
| | - Rajib Sahu
- Max-Planck-Institut für Eisenforschung GmbH, D-40237, Düsseldorf, Germany
| | - Christina Scheu
- Max-Planck-Institut für Eisenforschung GmbH, D-40237, Düsseldorf, Germany
| | - Daniel Primetzhofer
- Department of Physics and Astronomy, Uppsala University, S-75120, Uppsala, Sweden
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