Reaction of surface hydroxyl groups with VO4H3 on anatase surfaces

The reaction of surface hydroxyl groups with adsorbed VO4H3 on TiO2-anatase surfaces was investigated by means of the semiempirical molecular orbital method MSINDO. The (1 0 1), (0 0 1) and (1 0 0) surfaces of anatase were considered. They were modeled by appropriate two-dimensional cyclic clusters of TiO2. Stable structures of VO4H3 species on the (1 0 1), (0 0 1) and (1 0 0) surfaces were obtained by Born-Oppenheimer molecular dynamics simulations at 300 K and 600 K. The reaction of the hydrated vanadia species with the surface hydroxyl groups was studied using metadynamics techniques. It was found that the reaction between these species is only favorable on the (1 0 0) surface. In consequence the formation of hydrated polymeric chains (VO4H)n should take place on this surface.