The photocatalytic hydrogen evolution has attracted extensive attention owing to the increasing global energy crisis and environmental contamination. In this work, ZnWO4 nanoparticles decorated with CdS nanoparticles were successfully prepared for efficient visible-light photocatalytic hydrogen evolution. The morphological structure, crystal phase, chemical composition and photoelectrochemical performances of the as-prepared CdS-ZnWO4 composite photocatalysts were investigated by using various characterization techniques. Compared to bare ZnWO4, the CdS-ZnWO4 composite photocatalysts exhibited stronger visible-light absorption capability and enhanced photocatalytic hydrogen evolution activity under visible light irradiation. The hydrogen production rate of CdS-ZnWO4 could reach 57.98 mu mol/h/g, which was much higher than those of bare ZnWO4 and CdS samples. The enhanced photocatalytic hydrogen evolution activity could be attributed to the formation of heterojunction at the interface between CdS and ZnWO4 in the composite, which would facilitate the photo-generated electron hole separation and thus improve the photocatalytic activity of ZnWO4. On the basis of photo electrochemical measurements, a feasible mechanism for enhanced photocatalytic hydrogen evolution of CdS-ZnWO4 composite photocatalysts was also proposed. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.