Domain-limited surface oxygen vacancy in rutile TiO2 for enhancing photocatalytic hydrogen evolution

Defect engineering is an effective strategy for enhancing the photocatalytic performance of semiconducting metal oxides. In this study, we demonstrate a simple method to engineer oxygen vacancies (OVs) on the surface of rutile TiO 2 by the use of thiourea. No bulk phase defects or heteroatom doping are introduced during the hydrothermal reaction, while preserving the original morphology of rutile TiO 2 . It was observed that the structural synergies with surface OVs significantly alter the electronic structure, thereby extending the absorption region of rutile TiO 2 and promoting efficient separation and transport of photogenerated carriers to the surface. The rutile TiO 2 with OVs on its surface exhibits highly photocatalytic H 2 evolution activity as 54.7 mmol·g -1 ·h -1 (with 1 wt% Pt loading), with an apparent quantum efficiency (AQY) of 24.7% at 380 nm.