Enhanced photocatalytic activity of sonochemical derived ZnO via the co-doping process

In the present study, Co-ZnO and Co-Ni-ZnO nanoparticles were synthesized by sonochemical methods and the structural and optical properties were investigated through Fourier Transform Infrared spectroscopy (FTIR), UV-Vis spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM), X-Ray Diffraction (XRD), and Photoluminescence spectroscopy (PL) methods. Morphology of nanoparticles obtained a small granular shape with an average crystallite size of 60 nm. In addition, the direct band gap was calculated using Tauc's approach. Comparing with pure ZnO, the band gap of the doped-ZnO NPs is smaller and depends on the type of dopants. Moreover, photocatalytic activity of all samples was investigated by the degradation of methyl orange (MO) dye under UV irradiation in an aqueous medium. Co-Ni-ZnO possesses excellent photocatalytic activity for the degradation of MO when compared to Co-ZnO and ZnO. In addition, the photocatalytic activity of Co-ZnO improves in the presence of nickel dopant. Moreover, the photocatalyst could be reused for four times without remarkable loss of its activity.