Synthesis of Ce co-doped Ag–ZnO photocatalyst with excellent performance for NBB dye degradation under natural sunlight illumination

The synthesis of Ce co-doped Ag-ZnO (Ce-Ag-ZnO) has been successfully achieved by a solvothermal method. The synthesized catalyst was characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) images, diffuse reflectance spectra (DRS), photoluminescence spectra (PL), cyclic voltammetry (CV) and BET surface area measurements. The photocatalytic activity of Ce-Ag-ZnO was investigated for the degradation of Napthol Blue Black (NBB) dye in aqueous solution under solar light irradiation. Co-dopants shift the absorbance of ZnO to the visible region. Ce-Ag-ZnO is found to be more efficient than Ag-ZnO, Ce-ZnO, commercial ZnO, prepared ZnO, TiO sub(2)-P25 and TiO sub(2) (Merck) at pH 9 for the mineralization of NBB dye under solar light irradiation. The influences of operational parameters such as the amount of photocatalyst, dye concentration, initial pH on photo-mineralization of NBB have been analyzed. The mineralization of NBB dye has been confirmed by COD measurements. A degradation mechanism is proposed for the degradation of NBB under solar light. The catalyst is found to be reusable.