Understanding the interaction of water with anatase TiO2 (101) surface from density functional theory calculations

The behavior of water molecule on anatase TiO2 (101) surface has been investigated by density functional theory calculations. The primary purpose of this Letter is to clarify the distinctions between molecular adsorption and dissociative adsorption of water on anatase TiO2 (101) surface. By analyzing interaction potential forms and bonding mechanism, it is found that the dipole interaction is the crucial factor for water adsorption on anatase TiO2 (101) surface. The adiabatic potential energy surface calculations indicate that the on-surface diffusion of water molecule is anisotropy: its diffusion energy barrier along [010] direction is smaller than that of along [111¯]/[11¯1¯] direction.

► We model the water adsorption on anatase TiO2 (101) surface.
► Water favors molecular adsorption to dissociation adsorption on this surface.
► The dipole interaction cannot be ignored in this case.
► The on-surface diffusion of water molecule is anisotropy.