Fabrication of S-scheme Zn1-xCdxS/NiO heterojunction for efficient photocatalytic hydrogen evolution

Establishing S-heterojunction was considered to be effective strategy to accelerate the speed of photocatalytic hydrogen evolution. In this study, we synthesized the S-scheme Zn1-xCdxS/NiO heterojunction by growing Zn1-xCdxS (ZCS) nanoparticles on NiO nanosheets for efficient photocatalytic hydrogen evolution. The photogenerated holes in ZCS could rapidly quenching with the photogenerated electrons of NiO though a S-scheme process, leaving the photogenerated electrons in the conduction band (CB) of ZCS for reduction of H+. The hydrogen evolution reactivity of the optimal ZCS/NiO was 259.2 mmol g−1 h−1, with the apparent quantum efficiency (AQE) of 15.8 % at 420 nm, which was 4.3 and 1728.0 times that of ZCS nanoparticle and NiO nanosheet, respectively. More importantly, the hydrogen evolution rate of ZCS/NiO was still 462.5 μmol g−1 h−1 without adding the sacrificial agent. This work provided a view for constructing S-scheme heterojunction to enhance photocatalytic hydrogen evolution performance.