p-Si nanowire (Si-NW) arrays are successfully decorated with molybdenum sulfur (MS) clusters by a drop-casting method. The composited photocathode (MS/Si-NW) demonstrated an enhanced photoelectrochemical (PEC) hydrogen production performance, with a photocurrent density of 14.3 mA/cm(2) at a potential of 0 V vs. RHE under the illumination of the red part of simulated solar light (), > 590 nm, 27.3 mW/cm(2)). The photocathode also showed a good stability in the long-term photocatalytic hydrogen evolution measurement, and the Faradaic efficiency of hydrogen production was close to 100%. Additionally, the morphological, optical and wetting properties of the photoelectrodes were investigated in detail. On the basis of the results, it could be concluded that the enhanced PEC performance is attributed to the high surface area, low light reflection and good wetting property of Si-NW, together with a low overpotential for hydrogen evolution reaction (HER) of the molybdenum sulfur clusters. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.