Engineering self-doped surface defects of anatase TiO2 nanosheets for enhanced photocatalytic efficiency

Anatase TiO2 nanosheets with controlled locations of defects in the bulk or on the surface were successfully synthesized by finely adjusting the temperatures and amounts of added HF during hydrothermal synthesis. The TiO2 nanosheets with dominant surface defects exhibit much higher activity in photocatalytic water reduction to hydrogen than those with dominant bulk defects, unambiguously demonstrating the promotion effect of surface defects on the TiO2 photocatalysis. The surface defects can be act as the site both for trapping the photogenerated charges on the surface and for adsorbing and activating reactants, subsequently facilitating the photogenerated charges-participated surface reactions. These results offer a novel strategy to enhance the photocatalytic efficiency of TiO2 photocatalysts via engineering self-doped surface defects.