S-scheme Cu3P/TiO2 heterojunction for outstanding photocatalytic water splitting

TiO 2 photocatalysts are of great interest in the fields of environmental purification, new energy and so on, because of their non-toxicity, high stability, high redox ability and low cost. However, the photogenerated carriers are severely recombined, which limits the application of TiO 2 photocatalysts. Herein, S-scheme Cu 3 P/TiO 2 heterojunction composites were successfully synthesized by a simple and efficient microwave hydrothermal method, and the results show that the hydrogen production rate of Cu 3 P/TiO 2 is 5.83 mmol∙g −1 ∙h −1 under simulated sunlight irradiation, which is 7.3 and 83.3 times higher than that of pure TiO 2 and Cu 3 P, respectively. This excellent performance is derived from the internal electric field (IEF) and energy band bending generated by the S-scheme heterojunction formed between Cu 3 P and TiO 2 . The density functional theory (DFT) calculation indicates that the Cu 3 P possess smaller work function and more negative conduction band (CB) position than that of TiO 2 , which is very conducive to greatly improve the H + reduction ability and hydrogen production performance. This work provides a new idea for the reveal of electron transfer paths and active sites in S-scheme heterojunctions and deepens the mechanism understanding.