Facile preparation of Ni2P/ZnO core/shell composites by a chemical method and its photocatalytic performance

The typical SEM images and the schematic illustration of photocatalytic mechanism of as-prepared Ni2P/ZnO core/shell composites. •Ni2P/ZnO composites have been synthesized via a facile chemical precipitation method.•The effect of the amount of Zn2+ has been discussed.•Ni2P/ZnO composite exhibits an enhanced photocatalytic degradation activity.•A mechanism about the enhanced photocatalytic activity is proposed. Ni2P/ZnO core/shell composites were fabricated basing on combining hydrothermal route with a facile chemical precipitation method. The characterization results show that the composites are comprised of the hexagonal Ni2P microspheres and hexagonal ZnO nanoparticles. In which, ZnO nanoparticles coat on the surfaces of Ni2P microspheres and some of them even assemble to worm-like structure. During the coating process, Zn2+ was absorbed on the surface of Ni2P microspheres by electrostatic interaction and then formed ZnO shell. But excessive Zn2+ can affect the crystalline and formation of core-shell structure of Ni2P/ZnO composites, so it is necessary to control the amount of Zn2+. Choosing Methylene Blue (MB) as a typical organic dye, the as-prepared Ni2P/ZnO core/shell composites show the enhanced photocatalytic degradation activity, which may be due to its better adsorption ability and the effective separation of photogenerated electron–hole pairs.