Enhanced photocatalytic activity of supported Cu-doped ZnO nanostructures prepared by SILAR method

Cu-doped ZnO (CZO) nanostructures were prepared on a glass substrate using the successive ionic layer adsorption and reaction (SILAR) method. Copper (Cu) doping has been used as a key to enhance the photocatalytic activity of ZnO. X-ray diffraction (XRD) results revealed the polycrystalline nature of the nanostructures prepared with a hexagonal wurtzite structure of ZnO. The field emission scanning electron microscopy (FE-SEM) analysis showed a change of the morphology from a granular structure to a hexagonal structure and the particle size decreased with increasing copper concentration. The transmittance showed a decrease in the visible range with the increase of copper concentration and a decrease of the optical band gap values was observed. The X-ray photoemission spectroscopy (XPS) analysis indicated that copper was in a divalent state (Cu2+) which confirms the successful incorporation of copper ions into ZnO lattices. The photocatalytic activity of CZO nanostructures prepared by the SILAR method was studied for the first time. The photocatalytic study showed that an increase in copper concentration leads to an increase in degradation efficiency. CZO nanostructures showed an enhancement in degradation efficiency of about 52% compared to undoped ZnO.