Synthesis and characterization of ZnO/ZnS/CuS ternary nanocomposites as high efficient photocatalyst in visible light

The ZnO/ZnS/CuS ternary nanocomposites have been successfully synthesized by a simple and cost-efficient three-step synthetic route, namely homogeneous precipitation, chemical conversion and cation exchange. The structures, morphologies and optical properties of the prepared samples were characterized by powder X-ray diffraction, Field emission scanning electron microscopy and Ultraviolet-visible spectroscopy. The X-ray diffraction result demonstrates that the ternary material is the composite of hexagonal wurtzite ZnO, hexagonal wurtzite ZnS and hexagonal covellite CuS. The FESEM images of the ternary nanocomposites with thickness about 15 nm show they are nonuniform lamellas. Compared with ZnO and ZnO/ZnS, the ternary nanocomposites exhibit enhanced optical absorption property in visible-light region. Moreover, the visible-light photocatalysis of ZnO/ZnS/CuS ternary nanocomposites has remarkably improved and we attribute it to its excellent utilization efficiency of visible-light and gradient energy level structure.