Evolution of MoS2/ZnIn2S4 heterostructures driven by the 1T/2H phase ratio of MoS2 for enhanced photocatalytic hydrogen evolution

Abstract

Tailoring Z-scheme heterojunctions has ignited the interest of photocatalytic community due to their exceptional photocatalytic hydrogen evolution performance. In this study, we transformed the MoS2/ZnIn2S4 heterostructure type from a type I to an all-solid-state Z-scheme by modulating the ratio of 1T into 2H MoS2 . Under visible illumination, the photocatalytic hydrogen evolution rate of MoS2 /ZnIn2S4 heterostructure achieved up to 1.37 and 2.13 mmol g -1 h -1 , respectively, which were 4.7 and 7.4 times higher than that of pristine ZnIn2S4 . This over sevenfold improvement is attributed to three key factors: (1) the incorporation of MoS2 significantly expanded the visible-light harvesting capacity; (2) the average lifetime of photogenerated carriers was prolonged from 4.77 to 5.65 ns, indicating superior charge carrier separation and reduced recombination; (3) the mixed 1T-2H MoS2 provided a lower barrier for hydrogen evolution. This work offers valuable insights into tuning band edges and the heterostructure types, paving the way for more efficient photocatalytic hydrogen production.