Defect-rich MoS2/NiS2 nanosheets loaded on SiNWs for efficient and stable photoelectrochemical hydrogen production

•A novel 3D SiNWs@MoS2/NiS2 heterogeneous photocathode was prepared.•The defect-rich MoS2/NiS2 nanosheets provide more active sites and protective layers.•DFT calculation results reveal the mechanism of the performance improvement.•The H2 production of the photocathode under neutral condition reached 183 μmol·h−1.