Manipulating Oxygen\nVacancy in SrTiO<sub>3</sub> Nanoparticles\nto Achieve Enhanced Photoelectrochemical Performance in Water Splitting

Introducing oxygen vacancies into\nperovskite-type SrTiO<sub>3</sub> nanoparticles usually takes dual\nor multiple steps, which\nare not\nconducive to subsequent modification and application. Herein, a facile\nnonstoichiometric method is applied to synthesize a series of oxygen\nvacancy (V<sub>O</sub>)-doped SrTiO<sub>3</sub> (Sr<sub>1–<i>X</i></sub>TiO<sub>3</sub><sub>–δ</sub>) as a photoanode\nmaterial in photoelectrochemical (PEC) water-splitting reactions.\nExperimental results reveal a nonlinear relationship between the PEC\nperformance and V<sub>O</sub> concentration in SrTiO<sub>3</sub> nanoparticles.\nSr<sub>1–<i>X</i></sub>TiO<sub>3</sub><sub>–δ</sub> doped with an appropriate amount of V<sub>O</sub> can significantly\nenhance its light response and electrocatalytic activity. The optimal\nSr<sub>0.95</sub>TiO<sub>3</sub><sub>–δ</sub> demonstrated\nthe best PEC activity with an incident photon-to-current conversion\nefficiency of 3.144 times higher than that of pristine SrTiO<sub>3</sub>. Enhanced PEC activity is attributed to superior light absorption\nand retarded photogenerated charge carrier recombination. This work\nsystematically reveals the role of oxygen vacancies in SrTiO<sub>3</sub> nanoparticles for achieving enhanced PEC performance in water splitting,\nwhich may offer inspiration for defect engineering of perovskite oxides.