Efficient photocatalytic hydrogen evolution via interfacial engineering and charge carrier utilization with WSP/g-C3N4 S-scheme heterojunction

Abstract

The practical implementation of photocatalytic hydrogen generation faces challenges due to the rapid recombination of photogenerated electron-hole pairs. This study reports the synthesis of a WSP/g- C3N4 S-scheme heterojunction catalyst featuring exposed hydrogen evolution active W sites, achieved through in-situ P introducing. Remarkably, the WSP/g-C3N4 catalyst exhibits a superior photocatalytic hydrogen evolution rate of 3.92 mmol h−1 g−1, surpassing g-C3N4 and attaining 112 times the performance of pristine C3N4. A series of characterization techniques and Density functional theory (DFT) reveal that WSP/C3N4 possesses the following advantages as a photocatalyst: 1) Under visible light irradiation, the distinctively ordered and well-crystallized structure generates potential differences, facilitates charge transfers, and enhances the hydrogen evolution activity. 2) The coupling between WSP and g-C3N4 interfaces effectively promotes the directional migration of photogenerated electrons. 3) The shallow bound energy level introduced near the conduction band of WSP effectively prolongs the carrier lifetime. These features collectively contribute to the improved performance of photocatalytic hydrogen evolution. These features collectively contribute to the improved performance of photocatalytic hydrogen evolution. This finding suggests new ways to create organic/inorganic heterojunction composite photocatalysts for efficient hydrogen generation.