Nitrogen doping-mediated oxygen vacancies enhancing co-catalyst-free solar photocatalytic H2 production activity in anatase TiO2 nanosheet assembly

Introducing oxygen vacancies (Vo) into TiO2 photocatalyst has been considered an effective strategy for improving co-catalyst-free solar photocatalytic activity. However, the methods used to synthesize it require high pressure/temperature and/or hazardous/costly reagents. Here we propose Vo introduction, concomitant with N doping in TiO2, as an alternative strategy for achieving efficient co-catalyst-free solar photocatalytic activity under less extreme conditions. After calcination at 450 degrees C of mesoporous spherical assemblies of a layered titanate nanosheet containing N,N-dimethylformamide as its synthesis solvent in the structure, we successfully synthesized mesoporous spherical assemblies of nanosheets composed of anatase TiO2 nanoparticles with Vo mediated by N doping. This material exhibits good co-catalyst-free solar photocatalytic activity for hydrogen evolution via water splitting under irradiation with simulated solar light, which is considerably higher than that of typical co-catalyst-free defective TiO2 materials. We discuss the possible role of the introduced Vo in facilitating charge separation and raising photocatalytic efficiency.

Automated summary

Introducing oxygen vacancies (Vo) into TiO2 photocatalyst along with N doping is proposed as an alternative strategy for achieving efficient co-catalyst-free solar photocatalytic activity under less extreme conditions. The synthesized material exhibits good co-catalyst-free solar photocatalytic activity for hydrogen evolution via water splitting under irradiation with simulated solar light, showing higher efficiency compared to typical co-catalyst-free defective TiO2 materials. The introduced Vo is believed to play a role in facilitating charge separation and improving photocatalytic efficiency.