Green synthesis of CuO nanoparticles-loaded ZnO nanowires arrays with enhanced photocatalytic activity

Highlights: • CuO were spin-coated on the surface of ZnO nanowires by the sol-gel method. • CuO nanoparticles are dispersedly attached to the surface of the ZnO NWs. • CuO nanoparticles-loaded ZnO NWAs have a better photoelectrochemical properties. Promoting the separation of photogenerated carriers and expanding the range of light absorption are critical factors for improving photocatalytic performance. Here, CuO nanoparticles-loaded ZnO nanowires arrays (CuO@ZnO NWAs)were synthesized via a three-step chemical approach on ITO glass. The morphology results demonstrate that CuO nanoparticles are dispersedly attached to the surface of the ZnO NWAs. Comparing with ZnO NWAs, the absorption peak of the CuO@ZnO NWAs extends to the visible region. In addition, CuO@ZnO NWAs exhibit the higher photocurrent response and photodegradation efficiency of methylene blue (MB) under visible light irradiation relative to pure ZnO NWAs, which can be caused by the enhanced efficiency and broadened range light absorption and the efficient generation and separation of photo-generated electrons and holes based on the CuO@ZnO (p-n) heterogeneous structure. The findings confirm that the hierarchical CuO nanoparticles-loaded ZnO NWAs hold a great potential candidate for wastewater treatment applications.