Enhanced photocatalytic degradation of azo dye in aqueous solutions using Ba@Ag@ZnO nanocomposite for self-sensitized under sunshine irradiation

Abstract

The aqueous solutions of Trypan blue (TB) textile dye are totally mineralized when irradiated with prepared photocatalyst under sunshine. The intensity of the sunshine was measured using Lux meter. The prepared catalyst of barium loaded Ag@ZnO (Ba@Ag@ZnO) was successfully synthesized by the precipitation–decomposition process aided by ultrasound method. The catalyst was characterized by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive Spectrum (EDS), Transmission Electron Microscope (TEM), Diffuse Reflectance Spectra (DRS), Photoluminescence spectra (PL) and BET surface area measurements. The Ba@Ag@ZnO is found to be more efficient than Ag@ZnO, Ba@ZnO, commercial ZnO and bare ZnO at pH 7 for the mineralization of Trypan Blue dye. The effects of operational parameters such as the amount of photocatalyst, dye concentration, initial pH on photo mineralization of TB dye have been analyzed. The mineralization of TB has been confirmed by Chemical Oxygen Demand (COD) measurements and hydroxyl method. The results showed that the dye molecules were completely degraded to CO2 and H2O under sunshine irradiation. It is accomplished that sunshine induced poverty of textile dye in wastewater is a viable technique for wastewater treatment.