TY - JOUR
T1 - Adsorption of Au atoms on stoichiometric and reduced TiO2(1 1 0) rutile surfaces
T2 - A first principles study
AU - Wang, Yun
AU - Hwang, Gyeong S.
N1 - Funding Information:
The authors acknowledge the Welch Foundation (grant no. F-1535) for their financial support of this work.
PY - 2003/9/10
Y1 - 2003/9/10
N2 - Using ab initio quantum mechanical methods (DFT-GGA/LDA, pseudopotentials) we have investigated the adsorption properties of Au atoms on stoichiometric and reduced TiO2(110) rutile surfaces. This study predicts that the most stable adsorption site for the Au atom on the stoichiometric surface is on the fourfold hollow position over the fivefold-coordinated Ti and in-plane and bridging O atoms, indicated as the H2 site. At the H2 site, it is likely that the covalent and ionic bonding interactions with the fivefold-coordinated Ti and the bridging O, respectively, contribute synergistically to the Au adsorption. For Au adsorption over a neutral Fs0 center on the reduced surface, there is rather strong ionic bonding between the Au and surrounding sixfold-coordinated Ti atoms. The Au adsorption energy at the defect site is affected significantly by the presence of oxygen vacancies nearby along the [001] direction. Our DFT-GGA results clearly show that the binding of Au to an oxygen vacancy site is substantially stronger than to the stoichiometric surface.
AB - Using ab initio quantum mechanical methods (DFT-GGA/LDA, pseudopotentials) we have investigated the adsorption properties of Au atoms on stoichiometric and reduced TiO2(110) rutile surfaces. This study predicts that the most stable adsorption site for the Au atom on the stoichiometric surface is on the fourfold hollow position over the fivefold-coordinated Ti and in-plane and bridging O atoms, indicated as the H2 site. At the H2 site, it is likely that the covalent and ionic bonding interactions with the fivefold-coordinated Ti and the bridging O, respectively, contribute synergistically to the Au adsorption. For Au adsorption over a neutral Fs0 center on the reduced surface, there is rather strong ionic bonding between the Au and surrounding sixfold-coordinated Ti atoms. The Au adsorption energy at the defect site is affected significantly by the presence of oxygen vacancies nearby along the [001] direction. Our DFT-GGA results clearly show that the binding of Au to an oxygen vacancy site is substantially stronger than to the stoichiometric surface.
KW - Atom-solid interactions
KW - Density functional calculations
KW - Gold
KW - Low index single crystal surfaces
KW - Surface defects
KW - Surface structure, morphology, roughness, and topography
KW - Titanium oxide
UR - http://www.scopus.com/inward/record.url?scp=0041387545&partnerID=8YFLogxK
U2 - 10.1016/S0039-6028(03)00925-7
DO - 10.1016/S0039-6028(03)00925-7
M3 - Article
AN - SCOPUS:0041387545
SN - 0039-6028
VL - 542
SP - 72
EP - 80
JO - Surface Science
JF - Surface Science
IS - 1-2
ER -