Rational constructing of Zn0.5Cd0.5S-diethylenetriamine/g-C3N4 S-scheme heterojunction with enhanced photocatalytic H2O2 production

Photocatalytic hydrogen peroxide (H₂O₂) production (PHP) offers significant advantages to traditional production methods, including solar energy utilization, mild reaction conditions, environmental friendliness, pollution-free processes, sustainability, and high selectivity. However, despite its potential as a green and sustainable technology, photocatalytic H₂O₂ production (PHP) is constrained by limited visible light absorption by photocatalysts and the rapid recombination of photogenerated charge carriers, which reduce yield and efficiency. In this study, we synthesized an organic amine constrained Zn_0.5Cd_0.5S-DETA/g-C₃N₄ (ZCS-D/CN) S-scheme heterojunction via a hydrothermal method to enhance PHP. Anchoring ZCS-D on the surface of CN and forming an S-scheme heterojunction effectively prevented ZCS-D agglomeration, modulated the band structure of CN, and enhanced the migration and redox capabilities of photogenerated charge carriers. The optimized heterojunction (ZCS-D/CN) achieved a H₂O₂ yield of 5124 µmol g^-1 h^-1 in pure H₂O, significantly outperforming pure CN (24 µmol g^-1 h^-1) and ZCS-D (4012 µmol g^-1 h^-1). These results demonstrate that ZCS-D/CN S-scheme heterojunction holds substantial potential for photocatalytic applications, particularly in the efficient production of H₂O₂.