Nickel Complex Engineered Interface Energetics for Efficient Photoelectrochemical Hydrogen Evolution over p-Si

•A facile strategy was presented to develop photoelectrochemical hydrogen evolution system.•The p-Si/Ni1 system stands among the most efficent and stable p-Si/metal complexes systems.•P-Si/electrolyte interface energetics was engineered for efficient interface charge transfer.•The Ni1 complex driven surface water reduction process was revealed.