Journal Article

PreJuSER-19950

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Interaction of Au(16) Nanocluster with Defects in Supporting Graphite: A Density-Functional Study

Logsdail, A. J. ; Akola, J.FZJ*

2011
Soc. Washington, DC

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Please use a persistent id in citations: doi:10.1021/jp203274a

Abstract: Soft-landed adsorption of Au-16 on bilayered graphene is investigated using density functional theory. The orientation of the Au-16 cluster and number of neighboring surface vacancies affect the overall structural and electronic properties of the cluster. The results of the PBE, vdW-DF, and vdW-DF2 exchange-correlation functionals are compared for the cluster-substrate interaction for systems with and without defects. In the presence of defects size two and greater, an Au atom adsorbs into the topmost graphene layer; this strongly influences the binding energy (>3 eV), while inducing substantial bending in the carbon plane and altering electronic properties of the system. Though the T-d-symmetry and electronegative properties of the Au-16 structure change in the presence of greater neighboring defects, elements of the cagelike starting structure remain throughout. The electron localization function shows that the in-plane Au-C bonds are of delocalized (metallic) nature and there is a local charge transfer to the coordinating Au. However, the net charge transfer between adsorbate and substrate is considerable only for the defect-free case (0.8e to Au-16). Finally, the binding of O-2 molecules to the adsorbed Au-16 cluster is used to probe the potential catalytic activity of graphite and carbon nanotube systems, and in one case (for defect size two) the adsorbed O-2 switches on the catalytically active superoxo-state.

Keyword(s): J

Note: This work was carried out under the HPC-EUROPA2 project (Project Number: 228398) with the support of the European Community - Research Infrastructure Action of the FP7. Financial support from the EPSRC, U.K. (A.J.L., DTA Award Reference: EP/P504678/1), the University of Birmingham, U.K. (A.J.L.), and the Academy of Finland (J.A.) is acknowledged. The authors acknowledge R. L. Johnston for many useful and insightful conversations. Computational resources were provided by the Finnish IT Center for Science (CSC), Helsinki, Finland, the John von Neumann Institute for Computing (NIC), Forschungszentrum Julich, Germany, and the University of Birmingham, Edgbaston, U.K.<SUP>55</SUP>

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Contributing Institute(s):

1. Quanten-Theorie der Materialien (PGI-1)

Research Program(s):

1. Grundlagen für zukünftige Informationstechnologien (P42)
2. HPC-EUROPA2 - Pan-European Research infrastructure on High Performance Computing for 21st century Science (228398) (228398)

Appears in the scientific report 2011

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