Structural and Electronic Properties of a W3O9 Cluster Supported on the TiO2(110) Surface

The stoichiometric tritungsten oxide Cluster (W3O9) deposited on the TiO2(110) Surface has been investigated using first-principles density functional theory calculations. Various possible configurations mainly derived from molecular dynamics simulations have been considered. On the basis of the comparisons of thermodynamic stability and STM images, two isoenergetic structures with chirality relationship between the geometries of W3O9 Clusters can be tentatively assigned to be the most likely configurations under the experimental conditions, in which five new bonds including three Ti-O and two W-O bonds are formed at the interface. Due to the loss of three W=O groups, the low chemical reactivity of the W3O9 Cluster can be expected. After deposition of W3O9, the TiO2(110) Surface still retains the semiconducting character and the charge transfer Occurring between the Cluster and the substrate is small. The variation of surface dipole moment is sensitive to the orientation of the six-membered ring structure of W3O9. In addition, our results indicate that the properties of the TiO2(110) surface may be adjusted by deposition of nonstoichiometric tungsten oxides.