N-doping TiO2 spheres with enriched oxygen vacancies for photocatalytic hydrogen evolution

Introducing oxygen vacancies (Vo) into TiO 2 photocatalyst has been considered an effective strategy for improving solar photocatalytic activity. In this study, we used dodecylamine as a structure-directing agent to prepare amorphous hydrated TiO 2 spheres through a simple hydrolysis reaction. After calcination at 500 °C for 2h, we successfully synthesized spherical anatase TiO 2 with Vo mediated by N doping. By decorated with 1 wt% Pt as a cocatalyst, the resulting Vo-containing N-TiO 2 -2h spheres exhibited excellent performance under ultraviolet–visible illumination. The catalyst showed a hydrogen evolution rate of 1183.97 μmol g -1 h −1 , which is 1.4 times greater than that of the commercial anatase TiO 2 spheres with the same specific surface area. The enhanced photocatalytic activity of the Vo-containing Pt/N-TiO 2 -2h for hydrogen generation is attributed to that N-doping-induced Vo, which can produce electron trapping states to inhibit the direct recombination of photogenerated carriers. The presence of Pt co-catalysts further suppresses the recombination of electron–hole pairs, accelerating the rate of the entire photocatalytic reaction.