Defect enhances photocatalytic activity of ultrathin TiO2 (B) nanosheets for hydrogen production by plasma engraving method

As for practical application, ultrathin two-dimension (2D) materials have exhibited high performances in photocatalysis, electrocatalysis, and supercapacitors. Usually, when used 2D TiO2 (B) nanosheet as a photocatalyst, it absorbs only ultraviolet light, and several approaches have been taken to narrow the band gap of TiO2. Thus, we demonstrated a facile and environmental friendly method to enhancing hydrogen production by introducing defects of O vacancy and Ti3+ in surface and bulk TiO2 (B) nanosheets through the ambient-temperature plasma engraving treatment. After plasma treatment, the band gap of the 2D TiO2 (B) nanosheets decreased from approximately 3.13 eV–2.88 eV and the H2 evolution performance of them is almost twice as high as pristine TiO2 (B) nanosheets under AM 1.5 illumination. The enhanced photocatalytic performances arise from the doping defect of O vacancy and Ti3+, narrowing the energy band gap and increasing more active sites of material surface with function of plasma engraving. The findings in this work may provide a new approach for improving the photocatalytic activities of other metal oxides.