ZnS/Ni2P core/shell composites were successfully synthesized using a hydrothermal method. The composites have been characterized by XRD, SEM, TEM and the corresponding results showed that the composites were composed of the cubic ZnS microspheres, which were made up of ZnS nanoparticles, and Ni2P nanoparticles coated on the surfaces of ZnS microspheres. Compared with ZnS microspheres, ZnS/Ni2P core/shell composites showed enhanced photocatalytic degradation activity for pyronine B under UV irradiation. This may be related to the effective separation of photogenerated electron-hole pairs in ZnS/Ni2P composites which can greatly reduce the chance of their recombination. Furthermore, superoxide ions and hydroxyl radical can be more easily produced through ZnS/Ni2P composites, which is also beneficial for the degradation of pyronine B. (C) 2016 Elsevier Ltd. All rights reserved.