Double S-Scheme ZnS/ZnO/CdS Heterostructure Photocatalyst for Efficient Hydrogen Production

This work illustrates the novelty of double S-scheme ZnS/ZnO/CdS ternary heterojunction photocatalyst with efficient photocatalytic activity. The sample with optimal CdS content, ZnS/ZnO/CdS-14% (ZZC14%), displayed the maximum H2 evolution rate of 4.1 mmol<middle dot>g-1<middle dot>h-1. The maximum photocatalytic performance was approximately 2 and 13 times higher than their corresponding counterparts, ZnS/CdS and ZnO/ZnS, respectively. A high AQE of 19.8% under 420 nm was obtained. Additionally, the slight changes in H2 evolution activities and retentions of crystal structures after six successive cycles indicate the stability of the photocatalyst. In accordance with the theoretical calculations and experimental results, the remarkable enhancement in photocatalytic activity is attributed to fast electron transfer and separation as well as the intimate contact due to mutual interaction between S-scheme. This work highlights an innovative approach to constructing a dual S-scheme photocatalytic system with high separation and fast migration capabilities of photogenerated charge carriers for splitting water to produce hydrogen.