A simple hydrothermal process was developed to synthesize Co0.5Cd0.5S/g-C3N4 composite photocatalysts. The crystal structure and surface morphology were characterized with XRD and TEM. The chemical state on the material surface, the chemical structure as well as the ultraviolet visible light response of the photocatalyst were investigated with XPS and UV-vis DRS. The hydrogen production experiments indicated that the Co0.5Cd0.5S catalyst exhibits enhanced efficiency and stability with the addition of g-C3N4, which effectively inhibited the occurrence of photo-corrosion and promoted the separation efficiency of the photogenerated electron hole pairs. The highest rate of H-2 generation from the composite catalyst is up to 6.31 mmol g(-1)h(-1) under visible light (lambda > 400 nm). (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.