Structural and electronic properties of Au on TiO2(110)

The structure and electronic properties of 1-ML Au supported on TiO2(110) have been theoretically investigated using the full potential linearized augmented plane-wave method. Based on total-energy and atomic-force calculations, the preferential adsorption site for the Au adatom is predicted to be the atop site above the fivefold surface Ti atom, with a bond length of d(Au-Ti)=2.66 Angstrom and an adsorption energy of - 1.49 eV per adatom. The adsorption of Au enhances the binding energies of the valence bands and core levels of the surface Ti and O atoms, the An d bands are destabilized with metallic gap states appearing near the Fermi level. This au-substrate interaction leads to a more active Au site for the Au/TiO2(110) system compared to the Au(001) surface, in agreement with recent experimental observations.