Low Temperature and Controllable Formation of Oxygen Vacancy SrTiO3‐x by Loading Pt for Enhanced Photocatalytic Hydrogen Evolution

Oxygen vacancy plays a key role in the photocatalytic processes of oxide semiconductors. However, it usually needs high hydrogenation temperature to form oxygen vacancy for SrTiO3. To decrease the temperature, Pt was preloaded on SrTiO3 to transform H2 into the active hydrogen through hydrogen spillover. As a result, the surface oxygen vacancy of Pt/SrTiO3‐x forms at low temperature to 150 °C. Without Pt loading, the defects of SrTiO3 cannot occur even at 400 °C. As the hydrogenation temperature increases, the surface oxygen vacancy of Pt/SrTiO3‐x rises, and a thin disorder overlayer on the facet loaded with metal Pt appears at 400 °C; whereas at 600 °C, besides the disorder overlayer, the surface defects at the facets without Pt and bulk defects are produced, indicating the controllable formation of oxygen vacancies. With the increasing of hydrogenation temperature, the activity of Pt/SrTiO3‐x enhances, and reaches the maximum at 400 °C. The produced H2 amount of Pt/SrTiO3‐x prepared at 400 °C is about 3 times as high as that of Pt/SrTiO3. The activity of Pt/SrTiO3‐x obtained at 600 °C is significantly lower than that at 400 °C. The surface oxygen vacancies are responsible for the enhanced activity; while the decreased specific surface and bulk defects produced at high hydrogenation temperature reduce the activity. New method: The method is developed to produce oxygen vacancy for SrTiO3 at low temperature by hydrogen spillover due to photodeposited Pt. The formation of the oxygen vacancies is controllable. The surface oxygen vacancies formed at low temperature promote significantly photocatalytic hydrogen evolution; while the decreased specific surface and bulk defects produced at high hydrogenation temperature reduce the activity.