Oxygen Vacancy-Engineered S-Scheme Heterojunction of BiVO4@Type II Red Phosphorus for Efficient Photocatalytic Hydrogen Evolution via Pure Water Splitting.

Solar-driven photocatalytic hydrogen production utilizing S-scheme heterojunctions holds great potential due to their capacity for spatial carrier separation and maintaining a high redox potential. In this work, an S-scheme heterojunction consisting of oxygen vacancy (VO)-enriched BiVO4@Type II red phosphorus (BiVO4@RP) was synthesized by a facile ball-milling approach, resulting in Type II RP nanosheets enwrapping the surface of decahedral BiVO4. The introduction of VO in BiVO4 induces defect electronic states that serve as effective trapping sites for photogenerated electrons at the heterojunction interface. Consequently, the synergistic effect of VO in BiVO4 and intimate interfacial contact between BiVO4 and RP facilitate the migration of photo-electrons through an S-scheme transfer route, thereby enhancing the hydrogen production activity from pure water splitting. Remarkably, the optimized BiVO4@RP composite achieves a hydrogen evolution rate of 518.5 µmol·h-1·g-1 under simulated solar light irradiation. This study may provide valuable insights into the design of defect-modulated S-scheme heterojunction photocatalysts for efficient artificial photosynthesis.