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Jin C, Cheng L, Feng G, Ye R, Lu ZH, Zhang R, Yu X. Adsorption of Transition-Metal Clusters on Graphene and N-Doped Graphene: A DFT Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:3694-3710. [PMID: 35285652 DOI: 10.1021/acs.langmuir.1c03187] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Using the dispersion-corrected density functional theory (DFT-D3) method, we systematically studied the adsorption of 15 kinds of transition-metal (TM) clusters on pristine graphene (Gr) and N-doped graphene (N-Gr). It has been found that TMn (n = 1-4) clusters adsorbed on the N-Gr surface are much stronger than those on the pristine Gr surface, while 3d series clusters present similar geometries on Gr and N-Gr surfaces. The most preferred sites of TMs migrate from hollow to bridge to the top site on the Gr surface along the d series in the periodic table, while the preferred sites of TMs migrate in a much more complex manner on the N-Gr surface. It has also been found that charge transfer decreases along the d series for adsorbed clusters on both surfaces, but adsorbed clusters present less charge transfer on the N-Gr surface than on the Gr surface. What is more interesting is that some TM (Tc, Ru, and Re) clusters change the growth mechanism from the three-dimensional (3D) growth mode on the Gr surface to the two-dimensional (2D) growth mode on the N-Gr surface. At last, it has been found that adsorbed clusters are more dispersed on the N-Gr surface than on the pristine Gr surface due to growth and average aggregation energies.
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Affiliation(s)
- Chengkai Jin
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, Institute of Applied Chemistry, College of Chemistry, Nanchang University, No. 999 Xuefu Road, Nanchang 330031, P. R. China
| | - Lihong Cheng
- Key Laboratory of Surface Engineering of Jiangxi Province, Jiangxi Science & Technology Normal University, Nanchang 330031, P. R. China
| | - Gang Feng
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, Institute of Applied Chemistry, College of Chemistry, Nanchang University, No. 999 Xuefu Road, Nanchang 330031, P. R. China
| | - Runping Ye
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, Institute of Applied Chemistry, College of Chemistry, Nanchang University, No. 999 Xuefu Road, Nanchang 330031, P. R. China
| | - Zhang-Hui Lu
- Institute of Advanced Materials (IAM), College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, P. R. China
| | - Rongbin Zhang
- Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, Institute of Applied Chemistry, College of Chemistry, Nanchang University, No. 999 Xuefu Road, Nanchang 330031, P. R. China
| | - Xiaohu Yu
- Institute of Theoretical and Computational Chemistry, Shaanxi Key Laboratory of Catalysis, School of Chemical & Environment Sciences, Shaanxi University of Technology, Hanzhong 723000, P. R. China
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2
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Model Catalysis with HOPG-Supported Pd Nanoparticles and Pd Foil: XPS, STM and C2H4 Hydrogenation. Catal Letters 2021; 152:2892-2907. [PMID: 36196216 PMCID: PMC9525433 DOI: 10.1007/s10562-021-03868-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022]
Abstract
A surface science based approach was applied to model carbon supported Pd nanoparticle catalysts. Employing physical vapour deposition of Pd on sputtered surfaces of highly oriented pyrolytic graphite (HOPG), model catalysts were prepared that are well-suited for characterization by X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM). Analysis of the HOPG substrate before and after ion-bombardment, and of Pd/HOPG before and after annealing, revealed the number of “nominal” HOPG defects (~ 1014 cm−2) as well as the nucleation density (~ 1012 cm−2) and structural characteristics of the Pd nanoparticles (mean size/height/distribution). Two model systems were stabilized by UHV annealing to 300 °C, with mean Pd particles sizes of 4.3 and 6.8 nm and size/height aspect ratio up to ~ 10. A UHV-compatible flow microreactor and gas chromatography were used to determine the catalytic performance of Pd/HOPG in ethylene (C2H4) hydrogenation up to 150 °C under atmospheric pressure, yielding temperature-dependent conversion values, turnover frequencies (TOFs) and activation energies. The performance of Pd nanocatalysts is compared to that of polycrystalline Pd foil and contrasted to Pt/HOPG and Pt foil, pointing to a beneficial effect of the metal/carbon phase boundary, reflected by up to 10 kJ mol−1 lower activation energies for supported nanoparticles.
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3
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Franz D, Schröder U, Shayduk R, Arndt B, Noei H, Vonk V, Michely T, Stierle A. Hydrogen Solubility and Atomic Structure of Graphene Supported Pd Nanoclusters. ACS NANO 2021; 15:15771-15780. [PMID: 34633788 DOI: 10.1021/acsnano.1c01997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We investigated the atomic structure of graphene supported Pd nanoclusters and their interaction with hydrogen up to atmospheric pressures at room temperature by surface X-ray diffraction and scanning tunneling microscopy. We find that Ir seeded Pd nanocluster superlattices with 1.2 nm cluster diameters can be grown on the graphene/Ir(111) moiré template with high structural perfection. The superlattice clusters are anchored through the rehybridized graphene to the Ir support, which superimposes a 2.0% inplane compression onto the clusters. During hydrogen exposure at 10 mbar pressure and room temperature, a significant part of the clusters gets unpinned from the superlattice. The clusters in registry undergo an out-of-plane expansion only, whereas the detached clusters expand in in- and out-of-plane directions. The formation of a hydrogen rich PdHx α' phase was not observed. After exposure to 1 bar, the majority of the clusters are unpinned from superlattice sites, due to their surface interaction with hydrogen and possible spill over to the graphene support. Only minor sintering was observed, which is more pronounced for the unpinned clusters. The results give evidence that ultrasmall Pd clusters on graphene are a stable hydrogen storage system with reduced hydrogen storage hysteresis and maintain a large surface area for hydrogen chemisorption.
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Affiliation(s)
- Dirk Franz
- Deutsches Elektronen-Synchrotron (DESY), Hamburg, D-22607 Germany
- Physics Department, University of Hamburg, Hamburg, D-20355 Germany
| | - Ulrike Schröder
- Institute of Physics II, University of Cologne, Cologne, D-50937 Germany
| | - Roman Shayduk
- Deutsches Elektronen Synchrotron (DESY), Hamburg, D-22607 Germany
| | - Björn Arndt
- Physics Department, University of Hamburg, Hamburg, D-20355 Germany
- Deutsches Elektronen Synchrotron (DESY), Hamburg, D-22607 Germany
| | - Heshmat Noei
- Deutsches Elektronen Synchrotron (DESY), Hamburg, D-22607 Germany
| | - Vedran Vonk
- Deutsches Elektronen Synchrotron (DESY), Hamburg, D-22607 Germany
| | - Thomas Michely
- Institute of Physics II, University of Cologne, Cologne, D-50937 Germany
| | - Andreas Stierle
- Physics Department, University of Hamburg, Hamburg, D-20355 Germany
- Deutsches Elektronen Synchrotron (DESY), Hamburg, D-22607 Germany
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4
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Hartl T, Will M, Čapeta D, Singh R, Scheinecker D, Boix de la Cruz V, Dellmann S, Lacovig P, Lizzit S, Senkovskiy BV, Grüneis A, Kralj M, Knudsen J, Kotakoski J, Michely T, Bampoulis P. Cluster Superlattice Membranes. ACS NANO 2020; 14:13629-13637. [PMID: 32910634 DOI: 10.1021/acsnano.0c05740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cluster superlattice membranes consist of a two-dimensional hexagonal lattice of similar-sized nanoclusters sandwiched between single-crystal graphene and an amorphous carbon matrix. The fabrication process involves three main steps, the templated self-organization of a metal cluster superlattice on epitaxial graphene on Ir(111), conformal embedding in an amorphous carbon matrix, and subsequent lift-off from the Ir(111) substrate. The mechanical stability provided by the carbon-graphene matrix makes the membrane stable as a free-standing material and enables transfer to other substrates. The fabrication procedure can be applied to a wide variety of cluster materials and cluster sizes from the single-atom limit to clusters of a few hundred atoms, as well as other two-dimensional layer/host matrix combinations. The versatility of the membrane composition, its mechanical stability, and the simplicity of the transfer procedure make cluster superlattice membranes a promising material in catalysis, magnetism, energy conversion, and optoelectronics.
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Affiliation(s)
- Tobias Hartl
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Moritz Will
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Davor Čapeta
- Institute of Physics, Bijenička cesta 46, 10000, Zagreb, Croatia
| | - Rajendra Singh
- Faculty of Physics, Vienna University, Boltzmanngasse 5, 1090, Vienna, Austria
| | - Daniel Scheinecker
- Faculty of Physics, Vienna University, Boltzmanngasse 5, 1090, Vienna, Austria
| | - Virginia Boix de la Cruz
- MAX IV Laboratory and Division of Synchrotron Radiation Research, Lund University, Box 118, 22100 Lund, Sweden
| | - Sophia Dellmann
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Paolo Lacovig
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14 Km 163.5, I-34149 Trieste, Italy
| | - Silvano Lizzit
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14 Km 163.5, I-34149 Trieste, Italy
| | - Boris V Senkovskiy
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Alexander Grüneis
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Marko Kralj
- Institute of Physics, Bijenička cesta 46, 10000, Zagreb, Croatia
| | - Jan Knudsen
- MAX IV Laboratory and Division of Synchrotron Radiation Research, Lund University, Box 118, 22100 Lund, Sweden
| | - Jani Kotakoski
- Faculty of Physics, Vienna University, Boltzmanngasse 5, 1090, Vienna, Austria
| | - Thomas Michely
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Pantelis Bampoulis
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
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Will M, Bampoulis P, Hartl T, Valerius P, Michely T. Conformal Embedding of Cluster Superlattices with Carbon. ACS APPLIED MATERIALS & INTERFACES 2019; 11:40524-40532. [PMID: 31588723 DOI: 10.1021/acsami.9b14616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Iridium cluster superlattices on the graphene moiré with Ir(111) are embedded with elemental carbon through vapor-phase deposition. Using scanning tunneling microscopy and spectroscopy, we find that carbon embedding is conformal and does not deteriorate the excellent order of the iridium clusters. The thermal and mechanical stability of the embedded clusters is greatly enhanced. Smoluchowski ripening as well as cluster pick-up by the scanning tunneling microscopy tip are both suppressed. The only cluster decay path left takes place at an elevated temperature of around 1050 K. The cluster material penetrates through the graphene sheet, whereby it becomes bound to the underlying metal. It is argued that conformal carbon embedding is an important step towards the formation of a new type of sintering-resistant cluster lattice material for nanocatalysis and nanomagnetism.
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Affiliation(s)
- Moritz Will
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Pantelis Bampoulis
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Tobias Hartl
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Philipp Valerius
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Thomas Michely
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
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6
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Düll F, Meusel M, Späth F, Schötz S, Bauer U, Bachmann P, Steinhauer J, Steinrück HP, Bayer A, Papp C. Growth and stability of Pt nanoclusters from 1 to 50 atoms on h-BN/Rh(111). Phys Chem Chem Phys 2019; 21:21287-21295. [PMID: 31549113 DOI: 10.1039/c9cp04095a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The h-BN nanomesh on Rh(111) is used as eggbox-like template for the formation of arrays of Pt nanoclusters with a narrow size distribution. Nanoclusters with sizes from 1 up to 50 atoms are prepared simultaneously in a wedge-like structure by depositing a coverage gradient on the h-BN nanomesh, and thus can be investigated under identical conditions. We studied the preparation and properties of these Pt nanoclusters of different size in situ by high-resolution X-ray photoelectron spectroscopy and scanning tunneling microscopy. For a Pt coverage of 0.1 ML, all pores of the h-BN nanomesh are filled with nanoclusters with a remarkably uniform cluster size of ≈12 Pt atoms per pore, and high stability up to 400 K. Above 0.2 ML Pt, the clusters are less stable. The coverage dependent analysis shows that for Pt coverages below 0.1 ML, the number of nanoclusters is smaller - and the number of empty pores higher - than expected for a simple hit and stick mechanism. We assign this behavior to an initially higher mobility of the Pt atoms in a hot precursor state.
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Affiliation(s)
- Fabian Düll
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
| | - Manuel Meusel
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
| | - Florian Späth
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
| | - Simon Schötz
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
| | - Udo Bauer
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
| | - Philipp Bachmann
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
| | - Johann Steinhauer
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
| | - Hans-Peter Steinrück
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
| | - Andreas Bayer
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
| | - Christian Papp
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
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7
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Gleißner R, Creutzburg M, Noei H, Stierle A. Interaction of Water with Graphene/Ir(111) Studied by Vibrational Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11285-11290. [PMID: 31361486 DOI: 10.1021/acs.langmuir.9b01205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Water in confinement exhibits altered properties in molecular arrangement, bonding, and interaction with its neighboring environment, as compared to its bulk counterpart. In this work, periodically arranged D2O nano droplets of ∼1 nm size on top of a graphene/iridium moiré superstructure were investigated by Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS) under ultrahigh vacuum conditions at ∼120 K. The IR bands of D2O clusters differ significantly from those observed for bulk D2O amorphous solid water or crystalline ice phases. Blue-shifted symmetric and asymmetric stretching bands with narrower band widths and modified band intensity ratios were observed, pointing to an enhanced internal order and a reduced nearest neighbor distance. Furthermore, two IR bands of "dangling" deuterium atoms were detected originating from threefold coordinated water molecules at the surface of the clusters and at their interface to the graphene layer. The latter arose only with the transition from the water clusters to an amorphous solid water layer. We propose that upon coalescence, opposing local dipoles trigger a hydrogen bond rearrangement at the interface. Our results represent a first step toward an atomistic understanding of water in confinement.
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Affiliation(s)
- Robert Gleißner
- Deutsches Elektronen-Synchrotron (DESY) , Hamburg D-22607 , Germany
- Fachbereich Physik , Universität Hamburg , Hamburg 20146 , Germany
| | - Marcus Creutzburg
- Deutsches Elektronen-Synchrotron (DESY) , Hamburg D-22607 , Germany
- Fachbereich Physik , Universität Hamburg , Hamburg 20146 , Germany
| | - Heshmat Noei
- Deutsches Elektronen-Synchrotron (DESY) , Hamburg D-22607 , Germany
| | - Andreas Stierle
- Deutsches Elektronen-Synchrotron (DESY) , Hamburg D-22607 , Germany
- Fachbereich Physik , Universität Hamburg , Hamburg 20146 , Germany
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8
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Jørgensen AL, Duncan DA, Kastorp CFP, Kyhl L, Tang Z, Bruix A, Andersen M, Hammer B, Lee TL, Hornekær L, Balog R. Chemically-resolved determination of hydrogenated graphene-substrate interaction. Phys Chem Chem Phys 2019; 21:13462-13466. [PMID: 31187827 DOI: 10.1039/c9cp02059d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Functionalization of graphene on Ir(111) is a promising route to modify graphene by chemical means in a controlled fashion at the nanoscale. Yet, the nature of such functionalized sp3 nanodots remains unknown. Density functional theory (DFT) calculations alone cannot differentiate between two plausible structures, namely true graphane and substrate stabilized graphane-like nanodots. These two structures, however, interact dramatically differently with the underlying substrate. Discriminating which type of nanodots forms on the surface is thus of paramount importance for the applications of such prepared nanostructures. By comparing X-ray standing wave measurements against theoretical model structures obtained by DFT calculations we are able to exclude the formation of true graphane nanodots and clearly show the formation graphane-like nanodots.
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Affiliation(s)
- Anders L Jørgensen
- Department of Physics and Astronomy and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark.
| | - David A Duncan
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Claus F P Kastorp
- Department of Physics and Astronomy and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark.
| | - Line Kyhl
- Department of Physics and Astronomy and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark.
| | - Zeyuan Tang
- Department of Physics and Astronomy and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark.
| | - Albert Bruix
- Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany
| | - Mie Andersen
- Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany
| | - Bjørk Hammer
- Department of Physics and Astronomy and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark.
| | - Tien-Lin Lee
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Liv Hornekær
- Department of Physics and Astronomy and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark.
| | - Richard Balog
- Department of Physics and Astronomy and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark.
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9
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Alyabyeva N, Ouvrard A, Zakaria AM, Bourguignon B. Probing Nanoparticle Geometry down to Subnanometer Size: The Benefits of Vibrational Spectroscopy. J Phys Chem Lett 2019; 10:624-629. [PMID: 30673284 DOI: 10.1021/acs.jpclett.8b03830] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Understanding the role of nanoparticle size and shape in the binding of molecules is very relevant for heterogeneous catalysis and molecular electronics. The geometry of Pd nanoparticles (NPs) has been studied from very small clusters containing 4 atoms up to large (>500 atoms), well-faceted NPs. Their geometry was retrieved by combining scanning tunneling microscopy and vibrational sum frequency generation (SFG) spectroscopy of adsorbed CO. SFG has been revealed to be highly sensitive to the geometry of NPs smaller than 100 atoms by identifying the nature of CO adsorption sites. NP growth could be followed layer by layer in the critical size range corresponding to the transition from a nonmetallic to a metallic state and to oscillations of CO adsorption energy. NP height remained at two Pd planes up to 30 atoms, and adsorption energy minima correspond to the completion of successive layers.
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Affiliation(s)
- Natalia Alyabyeva
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS , Université Paris-Saclay , F-91405 Orsay , France
| | - Aimeric Ouvrard
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS , Université Paris-Saclay , F-91405 Orsay , France
| | - Abdoul-Mouize Zakaria
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS , Université Paris-Saclay , F-91405 Orsay , France
| | - Bernard Bourguignon
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS , Université Paris-Saclay , F-91405 Orsay , France
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10
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Martínez-Galera AJ, Gómez-Rodríguez JM. Pseudo-ordered distribution of Ir nanocrystals on h-BN. NANOSCALE 2019; 11:2317-2325. [PMID: 30662984 DOI: 10.1039/c8nr08928k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A 2D material consisting of a pseudo-ordered distribution of Ir nanocrystals supported on a h-BN/Rh(111) surface is presented here. The particular spatial distribution of the Ir nanoparticles is achieved thanks to the existence of a large variety of adsorption positions within the pores of the h-BN/Rh(111) nanomesh template with hexagonal symmetry. The resulting deviations of nanoparticle positions with respect to a perfect hexagonal lattice, which make this material of special interest in the field of optics, can be tuned by the temperature and the amount of Ir. Upon annealing, this material undergoes slight structural changes in the temperature range of 370-570 K and much more drastic ones, due to cluster coalescence, between 670 and 770 K. This relatively high onset of coalescence is encouraging for using this 2D material as a catalyst for reactions such as the oxidation of carbon monoxide or of nitrogen monoxide, which are especially relevant in the field of environmental science. Finally, metal nanostructures exhibiting regular geometries have been created from this material using a scanning tunneling microscope tip. Because of the insulating character of h-BN, these nanostructures could be very promising to use in the design of conductive nanotracks.
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Affiliation(s)
- Antonio J Martínez-Galera
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.
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11
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Jochmann K, Bernhardt TM. The influence of metal cluster lattices on the screening of image potential state electrons on graphene. J Chem Phys 2018; 149:164706. [DOI: 10.1063/1.5052643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Kira Jochmann
- Institute of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm, Germany
| | - Thorsten M. Bernhardt
- Institute of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm, Germany
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12
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Düll F, Schwaab V, Späth F, Bauer U, Bachmann P, Steinhauer J, Steinrück HP, Papp C. Sulfur oxidation on graphene-supported platinum nanocluster arrays. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.08.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Will M, Atodiresei N, Caciuc V, Valerius P, Herbig C, Michely T. A Monolayer of Hexagonal Boron Nitride on Ir(111) as a Template for Cluster Superlattices. ACS NANO 2018; 12:6871-6880. [PMID: 29920200 DOI: 10.1021/acsnano.8b02127] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The moiré of a monolayer of hexagonal boron nitride on Ir(111) is found to be a template for Ir, C, and Au cluster superlattices. Using scanning tunneling microscopy, the cluster structure and epitaxial relation to the substrate, the cluster binding site, the role of defects, as well as the thermal stability of the cluster lattice are investigated. The Ir and C cluster superlattices display a high thermal stability, before they decay by intercalation and Smoluchowski ripening. Ab initio calculations explain the extraordinarily strong Ir cluster binding through selective sp3 rehybridization of boron nitride involving B-Ir cluster bonds and a strengthening of the nitrogen bonds to the Ir substrate in a specific, initially only chemisorbed valley area within the moiré.
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Affiliation(s)
- Moritz Will
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Nicolae Atodiresei
- Peter Grünberg Institut (PGI-1) and Institute for Advanced Simulation (IAS-1) , Forschungszentrum Jülich and JARA , Jülich D-52425 , Germany
| | - Vasile Caciuc
- Peter Grünberg Institut (PGI-1) and Institute for Advanced Simulation (IAS-1) , Forschungszentrum Jülich and JARA , Jülich D-52425 , Germany
| | - Philipp Valerius
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Charlotte Herbig
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Thomas Michely
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
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14
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Düll F, Bauer U, Späth F, Bachmann P, Steinhauer J, Steinrück HP, Papp C. Bimetallic Pd–Pt alloy nanocluster arrays on graphene/Rh(111): formation, stability, and dynamics. Phys Chem Chem Phys 2018; 20:21294-21301. [DOI: 10.1039/c8cp03749c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We investigated the formation, stability, and dynamics of graphene-supported Pd–Pt alloy nanoclusters with in situ HR-XPS with CO as a probe molecule.
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Affiliation(s)
- Fabian Düll
- Lehrstuhl für Physikalische Chemie II
- Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Udo Bauer
- Lehrstuhl für Physikalische Chemie II
- Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Florian Späth
- Lehrstuhl für Physikalische Chemie II
- Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Philipp Bachmann
- Lehrstuhl für Physikalische Chemie II
- Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Johann Steinhauer
- Lehrstuhl für Physikalische Chemie II
- Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Hans-Peter Steinrück
- Lehrstuhl für Physikalische Chemie II
- Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Christian Papp
- Lehrstuhl für Physikalische Chemie II
- Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
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15
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Gubó R, Vári G, Kiss J, Farkas AP, Palotás K, Óvári L, Berkó A, Kónya Z. Tailoring the hexagonal boron nitride nanomesh on Rh(111) with gold. Phys Chem Chem Phys 2018; 20:15473-15485. [PMID: 29799587 DOI: 10.1039/c8cp00790j] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The pore diameter (depth) of the periodically corrugated h-BN monolayer (“nanomesh”) can be tuned allyoing Au into the Rh(111) surface.
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Affiliation(s)
- R. Gubó
- Extreme Light Infrastructure-ALPS
- ELI-HU Non-profit Ltd
- H-6720 Szeged
- Hungary
- Department of Applied and Environmental Chemistry, University of Szeged
| | - G. Vári
- Department of Applied and Environmental Chemistry, University of Szeged
- H-6720 Szeged
- Hungary
| | - J. Kiss
- MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group
- H-6720 Szeged
- Hungary
| | - A. P. Farkas
- Extreme Light Infrastructure-ALPS
- ELI-HU Non-profit Ltd
- H-6720 Szeged
- Hungary
- MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group
| | - K. Palotás
- MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group
- H-6720 Szeged
- Hungary
- Institute of Physics
- Slovak Academy of Sciences
| | - L. Óvári
- Extreme Light Infrastructure-ALPS
- ELI-HU Non-profit Ltd
- H-6720 Szeged
- Hungary
- MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group
| | - A. Berkó
- MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group
- H-6720 Szeged
- Hungary
| | - Z. Kónya
- Department of Applied and Environmental Chemistry, University of Szeged
- H-6720 Szeged
- Hungary
- MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group
- H-6720 Szeged
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16
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Vesselli E, Peressi M. Nanoscale Control of Metal Clusters on Templating Supports. STUDIES IN SURFACE SCIENCE AND CATALYSIS 2017. [DOI: 10.1016/b978-0-12-805090-3.00008-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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17
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Martins M, Wurth W. Magnetic properties of supported metal atoms and clusters. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:503002. [PMID: 27783566 DOI: 10.1088/0953-8984/28/50/503002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Clusters are small systems ranging from a few atoms up to several thousand atoms. They are of high interest in basic research, but also for applications due to their specific electronic, magnetic or chemical properties depending on size and composition. For small clusters, quantum size effects play an important role and specific material properties might be tailored by choosing a special size or composition of the cluster. Here, we review the magnetic properties of adatoms and supported small mass-selected transition-metal clusters in the few-atom limit investigated by x-ray magnetic circular dichroism spectroscopy in the soft x-ray regime. The influence of cluster size, composition, the cluster-surface and intra-cluster interaction on the spin and orbital magnetic moments will be discussed.
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Affiliation(s)
- Michael Martins
- Department of Physics, University of Hamburg, Luruper Chaussee 149, D-22761 Hamburg, Germany
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18
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Papp C. From Flat Surfaces to Nanoparticles: In Situ Studies of the Reactivity of Model Catalysts. Catal Letters 2016. [DOI: 10.1007/s10562-016-1925-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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19
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Roth SV. A deep look into the spray coating process in real-time-the crucial role of x-rays. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:403003. [PMID: 27537198 DOI: 10.1088/0953-8984/28/40/403003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Tailoring functional thin films and coating by rapid solvent-based processes is the basis for the fabrication of large scale high-end applications in nanotechnology. Due to solvent loss of the solution or dispersion inherent in the installation of functional thin films and multilayers the spraying and drying processes are strongly governed by non-equilibrium kinetics, often passing through transient states, until the final structure is installed. Therefore, the challenge is to observe the structural build-up during these coating processes in a spatially and time-resolved manner on multiple time and length scales, from the nanostructure to macroscopic length scales. During installation, the interaction of solid-fluid interfaces and between the different layers, the flow and evaporation themselves determine the structure of the coating. Advanced x-ray scattering methods open a powerful pathway for observing the involved processes in situ, from the spray to the coating, and allow for gaining deep insight in the nanostructuring processes. This review first provides an overview over these rapidly evolving methods, with main focus on functional coatings, organic photovoltaics and organic electronics. Secondly the role and decisive advantage of x-rays is outlined. Thirdly, focusing on spray deposition as a rapidly emerging method, recent advances in investigations of spray deposition of functional materials and devices via advanced x-ray scattering methods are presented.
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Affiliation(s)
- Stephan V Roth
- Deutsches Elektronen-Synchrotron (DESY), Notkestr. 85, D-22607 Hamburg, Germany. Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden
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20
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Moiré induced organization of size-selected Pt clusters soft landed on epitaxial graphene. Sci Rep 2015; 5:13053. [PMID: 26278787 PMCID: PMC4642513 DOI: 10.1038/srep13053] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 04/24/2015] [Indexed: 11/08/2022] Open
Abstract
Two-dimensional hexagonal arrays of Pt nanoparticles (1.5 nm diameter) have been obtained by deposition of preformed and size selected Pt nanoparticles on graphene. This original self-organization is induced, at room temperature, by the 2D periodic undulation (the moiré pattern) of graphene epitaxially grown on the Ir(111) surface. By means of complementary techniques (scanning tunneling microscopy, grazing incidence X ray scattering), the Pt clusters shapes and organization are characterized and the structural evolution during annealing is investigated. The soft-landed clusters remain quasi-spherical and a large proportion appears to be pinned on specific moiré sites. The quantitative determination of the proportion of organized clusters reveals that the obtained hexagonal array of the almost spherical nanoparticles is stable up to 650 K, which is an indication of a strong cluster-surface interaction.
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21
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Dedkov Y, Voloshina E. Graphene growth and properties on metal substrates. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:303002. [PMID: 26151341 DOI: 10.1088/0953-8984/27/30/303002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Graphene-metal interface as one of the interesting graphene-based objects attracts much attention from both application and fundamental science points of view. This paper gives a timely review of the recent experimental works on the growth and the electronic properties of the graphene-metal interfaces. This work makes a link between huge amount of experimental and theoretical data allowing one to understand the influence of the metallic substrate on the electronic properties of a graphene overlayer and how its properties can be modified in a controllable way. The further directions of studies and applications of the graphene-metal interfaces are discussed.
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Affiliation(s)
- Yuriy Dedkov
- SPECS Surface Nano Analysis GmbH, Voltastrasse 5, 13355 Berlin, Germany
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22
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23
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Steinrück HG, Magerl A, Deutsch M, Ocko BM. Pseudorotational epitaxy of self-assembled octadecyltrichlorosilane monolayers on sapphire (0001). PHYSICAL REVIEW LETTERS 2014; 113:156101. [PMID: 25375723 DOI: 10.1103/physrevlett.113.156101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Indexed: 06/04/2023]
Abstract
The structure of octadecyltrichlorosilane self-assembled monolayers (SAMs) on sapphire (0001) was studied by Å-resolution surface-specific x-ray scattering methods. The monolayer was found to consist of three sublayers where the outermost layer corresponds to vertically oriented, closely packed alkyl tails. Laterally, the monolayer is hexagonally packed and exhibits pseudorotational epitaxy to the sapphire, manifested by a broad scattering peak at zero relative azimuthal rotation, with long powderlike tails. The lattice mismatch of ∼ 1%-3% to the sapphire's and the different length scale introduced by the lateral Si-O-Si bonding prohibit positional epitaxy. However, the substrate induces an intriguing increase in the crystalline coherence length of the SAM's powderlike crystallites when rotationally aligned with the sapphire's lattice. The increase correlates well with the rotational dependence of the separation of corresponding substrate-monolayer lattice sites.
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Affiliation(s)
- H-G Steinrück
- Crystallography and Structural Physics, University of Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - A Magerl
- Crystallography and Structural Physics, University of Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - M Deutsch
- Physics Department and Institute of Nanotechnology, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - B M Ocko
- Condensed Matter Physics and Materials Science Department, Brookhaven National Lab, Upton, New York 11973, USA
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24
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Mechanical gate control for atom-by-atom cluster assembly with scanning probe microscopy. Nat Commun 2014; 5:4360. [DOI: 10.1038/ncomms5360] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 06/06/2014] [Indexed: 11/09/2022] Open
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25
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Schumacher S, Wehling TO, Lazić P, Runte S, Förster DF, Busse C, Petrović M, Kralj M, Blügel S, Atodiresei N, Caciuc V, Michely T. The backside of graphene: manipulating adsorption by intercalation. NANO LETTERS 2013; 13:5013-5019. [PMID: 24131290 DOI: 10.1021/nl402797j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The ease by which graphene is affected through contact with other materials is one of its unique features and defines an integral part of its potential for applications. Here, it will be demonstrated that intercalation, the insertion of atomic layers in between the backside of graphene and the supporting substrate, is an efficient tool to change its interaction with the environment on the frontside. By partial intercalation of graphene on Ir(111) with Eu or Cs we induce strongly n-doped graphene patches through the contact with these intercalants. They coexist with nonintercalated, slightly p-doped graphene patches. We employ these backside doping patterns to directly visualize doping induced binding energy differences of ionic adsorbates to graphene through low-temperature scanning tunneling microscopy. Density functional theory confirms these binding energy differences and shows that they are related to the graphene doping level.
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Affiliation(s)
- Stefan Schumacher
- II. Physikalisches Institut , Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
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