O2 adsorption and dissociation on an anatase (101) surface with a subsurface Ti interstitial

Abstract

O₂ molecule adsorption and dissociation on an anatase (101) surface with a subsurface Ti interstitial atom are studied using density functional theory (DFT) calculations coupled with the nudged elastic band (NEB) method. The subsurface Ti interstitial atom can facilitate O₂ adsorption and dissociation. When a single O₂ molecule is adsorbed onto the surface, after dissociation, the two O adatoms are strongly bonded to the surface and no longer active on the surface. Different from the case of a single O₂ molecule dissociation, two active dissociated oxygen atoms are generated when two O₂ molecules are adsorbed onto the surface near a subsurface Ti interstitial atom. These two active oxygen atoms can oxidize the toxic gases adsorbed onto the surface. For this situation, the subsurface Ti interstitial atom may be a key factor to improve the catalytic performance of TiO₂.