Dynamical properties of physically adsorbed water molecules at the TiO2 rutile-(1 1 0) surface

The dynamical properties of physically adsorbed water molecules on partially hydroxylated rutile-(1 1 0) surfaces have been studied via equilibrium Born–Oppenheimer molecular dynamics. It was found that water molecules were almost parallel to the surface. There is a coupling frequency of around 110 and 220 cm−1 between the translational modes of the water molecules and the upper layer of Ti and bridging oxygen atoms in the titania, respectively. Hydrogen bonds with the surface were observed to be stable, with stretch frequencies around 835–920 cm−1. Oxygen-vacancies were found to weaken hydrogen bonding between the water molecules’ protons and the bridging oxygen atoms.