Authors

Abstract

We revisited ab initio evaluations of the barrier energies along the possible diffusion paths of the defects in rutile TiO2 by using a diffusion Monte Carlo method. We found that Ti interstitials hopping along the c axis are identified as the major diffusion directing to the (001) surface, contradicting any of the previous density functional theory studies. Our finding reasonably explains recent experiments reporting that the photocatalytic activity in the (001) surface is superior to that in the (110) surface: The faster Ti diffusion directing to the (001) surface leads to the better self-compensation ability and maintains its photocatalytic activity.