Ab Initio Studies of Anatase TiO2 (101) Surface-supported Au8 Clusters

Author(s): A. Mikolajczyk, H. P. Pinto, A. Gajewicz, T. Puzyn, J. Leszczynski.

Journal Name: Current Topics in Medicinal Chemistry

Volume 15 , Issue 18 , 2015

Become EABM
Become Reviewer

Graphical Abstract:


Abstract:

Supported transition metals on TiO2 surfaces have shown exceptional catalytic properties in many important process such as CO oxidation, selective propane oxidation, hydrogenation, water adsorption and other catalytic and photocatalytic oxidation reaction at low-temperature. Among the three polymorphs of TiO2, the anatase crystal is the more photoactive. The anatase (101) surface attracts more attention since it has lower surface energy relative to (001) and (100) surfaces and it is observed to adsorb small molecules on its surface. Using density-functional theory (DFT) with on-site Coulomb interactions corrections, we have computed the structural and electronic properties of selected Au8 clusters interacting with clean and reduced anatase TiO2(101) surfaces. The computed adsorption energies are suggesting that the considered Au8 clusters are only physisorbed onto pristine TiO2(101) surface. Oxygen vacancies are found to enhance the absorption of Au8 on the Ti2(101) surface. Accurate simulations required spin polarized DFT since the ground state of Au8 interacting with defective TiO2(101) shows magnetic solutions. The results show that Au8 clusters are chemically bonded to the surface around the locality of the oxygen vacancy. The surface oxygen vacancy is found to be energetically more favourable than sub-surface oxygen vacancy configuration. These vacancy sites may act as nucleation sites for small Au clusters or Au atoms. Finally, the computed electronic structure of all the Au8/TiO2(101) configurations considered in this work are analysed in the light of available experimental data.

Keywords: Density-functional theory, TiO2 anatase, surface (101), Au-cluster, vdW-DF, Electronic structure.

Rights & PermissionsPrintExport Cite as


Article Details

VOLUME: 15
ISSUE: 18
Year: 2015
Page: [1859 - 1867]
Pages: 9
DOI: 10.2174/1568026615666150506151826
Price: $58

Article Metrics

PDF: 25