2D/2D Nb₃O₇F/g-C₃N₄ Heterojunction Photocatalysts with Enhanced Hydrogen Evolution Activity

Constructing two-dimensional (2D)/2D heterojunctions with intimate interfacial contact is of great importance to achieve high photocatalytic efficiency for hydrogen evolution. Herein, 2D/2D niobium oxyfluoride (Nb3O7F)/graphitic carbon nitride (g-C3N4) heterojunction photocatalysts were prepared by a two-step hydrothermal/calcination method. As expected, the obtained 2D/2D Nb3O7F/g-C3N4 heterojunctions exhibited a high photocatalytic hydrogen evolution rate of 1242.0 μmol h–1 g–1, which was approximately 3 times higher than that of pure g-C3N4 (427.2 μmol h–1 g–1). Furthermore, cycling experiments verified that the heterojunctions have good stability after four cycles. The remarkable photocatalytic activity was predominantly attributed to the enhanced specific surface area, the improved photogenerated electron/hole separation efficiency, and the inhibited carrier recombination. This work may give a deep insight into heterojunction photocatalysts for application of hydrogen production.