G-C 3 N 4 Nanosheets Coupled with TiO 2 Nanosheets as 2D/2D Heterojunction Photocatalysts Toward High Photocatalytic Activity for Hydrogen Production

TiO 2 /g-C 3 N 4 2D/2D heterojunction nanocomposites were successfully synthesized through a facile self-assembly method. The structure characterization results shows good interaction between TiO 2 nanosheets and g-C 3 N 4 nanosheets. The photocatalytic activity of TiO 2 /g-C 3 N 4 samples were measured by hydrogen production in water splitting under visible light irradiation, which was found that the composites enhance the photocatalytic activity clearly compared to pure g-C 3 N 4 and TiO 2 nanosheets. The results could attribute to the formation of 2D heterojunction because of the stimulative charge transfer, promotional separation efficiency of photoexcited electron and hole and the suitable band positions. Besides, the samples exhibited substantial stability under visible light irradiation by the recycling experiments. The feasible photocatalytic mechanism was minutely discussed, which could explain the enhanced photocatalytic activity. Graphical Abstract