Design of S-scheme CdS/La₂O₃ heterojunction for excellent photocatalytic H₂ evolution performance under simulated sunlight irradiation

Constructing S-scheme heterojunction photocatalysts with promising H₂ evolution performance remains challenging. Herein, a series of S-scheme CdS/La₂O₃ heterojunctions is designed and prepared through a microwave-assisted hydrothermal process to explore photocatalytic H₂ evolution from water-glycerol mixture. The optimized CdS/La₂O₃ photocatalyst demonstrates an excellent H₂ evolution rate of 18.50 mmolg⁻¹h⁻¹ from water-glycerol mixture under simulated sunlight irradiation, exhibiting a 14.5-fold and 26.8-fold enhancement compared to pure CdS (1.28 mmolg⁻¹h⁻¹) and La₂O₃ (0.69 mmolg⁻¹h⁻¹), respectively. The improved performance is primarily assigned to the S-scheme heterojunction formed between La₂O₃ and CdS, which promotes the separation and migration of photoinduced electron-hole pairs. Additionally, the optimized CdS/La₂O₃ photocatalyst manifests strong stability, exhibiting no significant performance loss in the H₂ evolution rate over 20 h of recycling experiments. This work facilitates valuable insights for constructing high-performance and stable S-scheme photocatalysts for H₂ evolution.