Here we report a p-Si photocathode decorated with nickel complex Ni(TEOA)(2)Cl-2 (Nil) in acidic aqueous solution (pH = 0.3) for photoelectrochemical (PEC) H-2 generation. Compared to bare p-Si, p-Si/Nil electrode exhibits significantly enhanced PEC performance, with higher cathodic photocurrent and exceptional lower onset potential. A relatively high photocurrent density of 5.57 mA/cm(2) was obtained at 0.0 V vs. reversible hydrogen electrode (RHE) under simulated 1 Sun illumination, which is even comparable to that of p-Si/Pt. Furthermore, the highly active p-Si/Nil electrode shows a remarkable stability over 24 h. The possible catalysis mechanism of Nil for p-Si in the PEC H-2 evolution process was also proposed in detail. The excellent PEC performance should be attributed to the Nil engineered p-Si/electrolyte interface energetics and the Nil catalyzed water reduction reaction, leading to robust hydrogen generation and excellent PEC stability. The present study made a deep insight into the engineered interface charge transfer and catalyst -driven surface water reduction processes at the semiconductor/electrolyte interface, which could provide some referable guidelines for fabricating highly efficient PEC system for solar 112 generation from the viewpoint of interface energetics engineering with metal complexes.