Abstract
In this study, dual S-scheme ZnIn2S4-Al2O3-ZnO (ZIS-Al-Zn) heterojunctions were produced by a facile, low cost, and rapid combustion technique. These heterojunctions accelerated the photocatalytic hydrogen production due to the multi-channel-promoted separation of photocarriers. By optimizing the content of the components, the synthesized ZIS-Al-Zn composite with 20 wt% of ZnIn2S4 and 30 wt% of Al2O3 in the ZIS-Al-Zn composite demonstrated the highest hydrogen production rate of 54.2 mmol g-1 h-1, which was nearly 11 and 8.30 times better than ZnO-Al2O3 and ZnO-ZnIn2S4 composites, respectively. The results of DRS, PL, EIS, LSV, and CV techniques showed the highest shift in the light absorption, rapid interfacial transfer, and quenched recombination of photocarriers over the ternary ZIS-Al-Zn composite than single and binary catalysts. The obtained results revealed the formation of a dual S-scheme mechanism of transfer of photocarriers in ZIS-Al-Zn heterojunctions, contributing to better hydrogen production efficiency. The optimized ZIS-Al-Zn composite also exhibited good stability and reusability.