A force field for the interaction of water with TiO ₂ surfaces

We develop a force field for the interaction of molecularly and dissociatively adsorbed water with surfaces of TiO ₂ by modifying the potential proposed by Bandura and Kubicki (J. Phys. Chem.2003, 107, 11072). We test the force field by computing binding energies and conformations for molecular adsorption on the (101) and (112) surfaces of anatase and the (110) surface of rutile and dissociative adsorption on the bulk-terminated (001) surface of anatase and the (110) surface of rutile for various water surface coverages. These quantities exhibit good agreement with results from first-principles density functional theory and experiment. We use molecular dynamics (MD) simulations to obtain density profiles and statistics of hydrogen bonding for water monolayers and bilayers adsorbed on anatase (101) and these results are in good agreement with ab initio MD. The potential is suitable for large-scale MD simulations of TiO ₂ in aqueous environments.