Formation of self-assembled hierarchical structure on Zn doped in CuO nanoparticle using a microwave-assisted chemical precipitation approach

In the present work, CuO and Cu 1-x Zn x O were synthesized with the function of the Zn doping ratio by microwave-assisted chemical precipitation approach. The X-ray diffraction pattern shows that the mono-phase CuO with a mono-clinical structure and no other secondary phase has been observed for the Cu 1-x Zn x O with different Zn ratio and confirms CuO lattice does not get destroyed by the addition of Zn. The Raman spectra and HR-TEM analysis support the XRD results. The self-assembled hierarchical flower morphology was obtained for the higher doping ratio of Zn. The energy dispersive analysis of X-ray spectrum confirms the presence of Zn in the CuO lattice and the stoichiometry obtained. The optical band gap was found to be 1.78 eV for CuO nanoparticles, and the values are between 1.80 and 2.29 eV for Zn-doped CuO. For higher Zn-doped CuO, optical band splitting was observed due to flower-like morphology. The recombination of an electron–hole was reduced for higher doping ratio nanoparticles. These properties are needed for photocatalytic application.