Water Interaction with native defects on rutile TiO2 nanowire: Ab initio calculations

Adsorption of water molecules on stoichiometric and defective surfaces of rutile TiO2 nanowire oriented along the [(1) over bar 10] direction is investigated using density function theory calculations. We have investigated, in particular, O and Ti vacancies where energetic, structural, and electronic properties were evaluated. It was found that the water molecules interacting with O-vacancy undergo spontaneous dissociation, forming hydroxyl groups bound to Ti atoms and other OH groups formed by surface O and H-water. The same is not found in the case of perfect and Ti-vacancy containing nanowire. This dissociation of water molecules is due to charge transfer from neighboring Ti atom, which is polarized due to the O-vacancy. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3556276]