In2S3/Red Phosphorus S-Scheme Heterostructures With Accelerated Interfacial Charge Transfer for Efficient Photocatalytic Hydrogen Evolution.

Abstract

Severe recombination of photogenerated charge carriers remains a critical bottleneck limiting the photocatalytic hydrogen evolution (PHE) performance of single-component semiconductors. Herein, a series of In2S3/HRP (ISP) S-scheme heterojunctions were constructed via a hydrothermal strategy for efficient PHE. Comprehensive characterizations combined with density functional theory (DFT) calculations confirmed the successful formation of the S-scheme heterojunction and revealed that the strong interfacial electric field (IEF) promoted the directional migration and separation of photogenerated charge carriers across the interface. The optimal 1-30ISP photocatalyst achieved a PHE rate of 865.82 µmol g-1 h-1 under simulated sunlight irradiation, representing approximately 28- and 3-fold enhancements over pristine In2S3 and HRP, respectively. The markedly improved photocatalytic performance was mainly attributed to the S-scheme charge transfer pathway, which effectively promoted the spatial separation of photogenerated charge carriers while preserving highly reductive and oxidative active sites, thereby optimizing interfacial charge transfer kinetics. This work provides valuable insights into the rational design of S-scheme heterojunction photocatalysts with efficient charge separation and strong redox capability for solar-driven hydrogen evolution.