Synthesis, characterization and investigation of ZnO @ Cu/CuO core-multishell nanoparticles for solar energy harvesting

n-ZnO core @ Cu/p-CuO multishell nanoparticles were synthesized by a two step wet chemical process. In the first step, wurtzite ZnO nanoparticles were prepared by simple precipitation technique using ZnCl₂ and NaOH precursors. The prepared nanoparticles were further powdered by ball milling technique. The prepared ZnO nanoparticles were coated with copper shell by electroless plating technique. The CuO film was later formed on the copper shell by air oxidation. The ZnO@Cu/CuO core-multishell nanoparticles were characterized using elemental analysis, X-ray diffraction and electron microscopic studies. BET nitrogen gas adsorption technique was employed to determine the specific surface area of ZnO@Cu/p-CuO core-multishell nanoparticles. Diffused reflectance spectroscopy (DRS) was used to measure the band gap of core-multishell nanoparticles. Tauc plot was use to determine the optical band gap (Eg) of the nanoparticles. The DRS analysis suggests the Core-multishell nanoparticles have wide band gap from near ultraviolet to visible and better light absorption strength. The n-ZnO @ Cu/p-CuO core-multishell nanoparticles may find application in solar energy harvesting.