Oxygen Vacancy Engineering of Titania-Induced by Sr²⁺ Dopants for Visible-Light-Driven Hydrogen Evolution

A Sr²⁺-doping strategy is developed to engineer rich oxygen vacancies in porous titania for boosting visible-light-driven photocatalytic activity. The incorporation of strontium, with a larger atom radius than titanium, leads to the release of a lattice oxygen atom in the titania, causing the generation of an oxygen vacancy. The optimal Sr²⁺-doped titania sample with rich oxygen vacancies achieves a photocatalytic hydrogen production rate as high as 1092 μmol h^-1 g^-1, which is 4 and 16 times higher than the unmodified titania with less oxygen vacancies and the bench-marked P25, respectively.