Theoretical Confirmation of the Enhanced Facility to Increase Oxygen Vacancy Concentration in TiO₂by Iron Doping

The effect of Fe-doping on the oxygen vacancy energy formation and on the electronic structure of stoichiometric bulk and (001) surface of TiO2 anatase has been studied by means of periodic density functional calculations within the GGA+U approach. The vacancy energy formation is always lower for the surface than for the bulk. The presence of Fe causes only a minor perturbation of the atomic structure of anatase but strongly reduces the oxygen vacancy energy formation, especially at the surface. The present results provide additional and independent support to the claim that the enhanced catalytic activity of Au nanoparticles supported on Fe-doped TiO2 toward CO oxidation has its origin in the ease to create oxygen vacancies in the support.