Kinetics of oxygen interstitial injection and lattice exchange in rutile TiO2

Abstract

The existence of a facile surface pathway for generation of O interstitials (Oi) in rutile that can facilitate annihilation of O undesirable vacancies has been demonstrated recently. Through isotopic self-diffusion experiments, the present work determines a value of approximately 1.8 eV for the activation energy of Oi injection from TiO2 (110). The mean path length for Oi diffusion decreases by nearly an order of magnitude upon adsorption of 0.1 monolayer of sulfur. Sulfur apparently inhibits the surface annihilation rate of Ti interstitials, lowering their bulk concentration and the corresponding catalytic effect they seem to exert upon Oi exchange with the lattice. © 2014 AIP Publishing LLC.