Oxidation and Photo-Oxidation of Water on TiO2Surface

The oxidation and photo-oxidation of water on the rutile TiO 2 (110) surface is investigated using density functional theory (DFT) calculations. We investigate the relative stability of different surface terminations of TiO 2 interacting with H 2 O and analyze the overpotential needed for the electrolysis and photoelectrolysis of water. We found that the most difficult step in the splitting of water process is the reaction of a H 2 O molecule with a vacancy in the surface to form an adsorbed hydroxyl group (OH*). Comparison to experiment shows that the computed overpotential for O 2 evolution (0.78 V) is available under the experimental conditions required for both oxygen and hydrogen evolution.