SnS₂ Quantum Dots Decorated MoS₂ Nanosheets Enabling Efficient Photocatalytic H₂ Evolution in CO₂ Saturated Water

SnS₂/MoS₂ heterojunction nanocomposite was prepared by a one-step hydrothermal synthesis method. The nanocomposite exhibited much improved photocatalytic hydrogen evolution performance in CO₂ saturated solution compared with pure MoS₂ and SnS₂ samples. The improved photocatalytic activity was attributed to the S-scheme heterojunction structure between SnS₂ quantum dots and MoS₂ nanosheets which facilitate electron-hole separation both in MoS₂ and SnS₂. In the S-scheme structure, the strong reduction ability of SnS₂ quantum dots was well maintained for the improved H₂ evolution. In situ DRIFT studies allowed us to suggest reaction pathways from CO₂ and H₂O to photocatalytic H₂, CO, and CH₄ generation.