Enhanced photocatalytic hydrogen evolution from: In situ formation of few-layered MoS₂/CdS nanosheet-based van der Waals heterostructures

Here we report for the first time that the H₂ bubbles generated by photocatalytic water splitting are effective in the layer-by-layer exfoliation of MoS₂ nanocrystals (NCs) into few layers. The as-obtained few layers can be in situ assembled with CdS nanosheets (NSs) into van der Waals heterostructures (vdWHs) of few-layered MoS₂/CdS NSs which, in turn, are effective in charge separation and transfer, leading to enhanced photocatalytic H₂ production activity. The few-layered MoS₂/CdS vdWHs exhibited a H₂ evolution rate of 140 mmol g_(CdS)^-1 h^-1 and achieved an apparent quantum yield of 66% at 420 nm.