A novel p–n heterojunction Mn0.25Cd0.75S/Co3O4 for highly efficient photocatalytic H2 evolution under visible light irradiation

The construction of p–n heterojunction is an efficient strategy to restrain photogenerated charge carriers recombination and enhance the photocatalytic efficiency toward H 2 evolution from water splitting. Herein a novel p–n heterojunction Mn 0.25 Cd 0.75 S/Co 3 O 4 was synthesized via facile hydrothermal method. Photocatalytic H 2 evolution of as-synthesized Mn 0.25 Cd 0.75 S/Co 3 O 4 composites in the absence of noble metal co-catalysts under visible light irradiation ( λ  ≥ 400 nm) was investigated. The results demonstrated that photocatalytic H 2 evolution of Mn 0.25 Cd 0.75 S was significantly enhanced by loading Co 3 O 4 nanoparticles . It was confirmed that 0.48 wt% of Co 3 O 4 loading content achieved the highest H 2 evolution rate of 25.71 mmol/g/h, which was about 5.35 times higher than that of pure Mn 0.25 Cd 0.75 S. The remarkably improved photocatalytic activity could be attributed to the formation of the p–n junction at the interface between Mn 0.25 Cd 0.75 S and Co 3 O 4 , effectively promoting interfacial charge transfer and separation. This work revealed that the p–n heterojunction Mn 0.25 Cd 0.75 S/Co 3 O 4 may be a promising candidate for efficient energy conversion.