Defective ultra-thin two-dimensional g-C₃N₄ photocatalyst for enhanced photocatalytic H₂ evolution activity

The two-dimensional semiconductor photocatalytic material has excellent photocatalytic H₂ evolution activity. In order to further improve the hydrogen production activity of g-C₃N₄, this study improved the preparation process of g-C₃N₄ and obtained a new photocatalyst (name H-CN) with a higher absorption range, larger specific surface area, and faster hydrogen production activity. Compared with the originally prepared g-C₃N₄, the H-CN absorption range has been improved, and the utilization of visible light has reached 650 nm. When the doping amount of Pt cocatalyst was 1.0 wt%, the H-CN demonstrates excellent photocatalytic hydrogen production activity, with a hydrogen production rate of 4.3 mmol h^-1·g^-1, which was 7.0 times higher than that pure 1.0 wt% Pt/g-C₃N₄. The fluorescence spectroscopy of H-CN showed better separation of carriers and longer lifetime. This study has guiding significance for the preparation of subsequent ultra-thin nanosheet photocatalysts and the establishment of high-efficiency photocatalytic systems.