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

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O2 molecule is adsorbed onto the surface, after dissociation, the two O adatoms are strongly bonded to the surface and no longer active on the surface.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.