Complex-directed hybridization of CuO/ZnO nanostructures and their gas sensing and photocatalytic properties

Novel CuO/ZnO hybrid nanostructures have been prepared by the complex-directed hybridization and subsequent calcination. In the hybridization process, Zn(OH)42− ions in the NaOH solution not only served as the ZnO precursor, but also directed the precipitation of CuO. The synthesized CuO/ZnO nanostructures were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and diffuse reflectance UV–vis spectroscopy (UV-DRS). XRD results confirmed the presence of CuO and ZnO phases in the hybrid nanostructures. Morphological analysis showed that flower-like and core–shell CuO/ZnO nanostructures and CuO/ZnO nanoparticles were selectively prepared by adjusting the precipitation temperature. Spectral analysis showed that the hybrids displayed a strong absorption in the visible light range of 400–800 nm. Subsequently, gas sensing measurements revealed that the synthesized CuO/ZnO hybrids exhibited a p-type sensing behavior in response to reducing gases, such as acetone, ethanol, and xylene. In addition, the photo-degradation of Rhodamine B (RhB) by the hybrids was evaluated. The proposed strategy opens a new route to metal oxide-based hybrid nanostructures for applications in catalysis, gas sensor, and photocatalysis.