Enhanced photocatalytic degradation of textile wastewater using Ag/ZnO thin films

In this work, photodegradation of a synthetic textile wastewater composed of a mixture of three reactive azo dyes (RO 122, RR 195 and RY 145) was performed using silver doped zinc oxide (Ag/ZnO) thin films. The photocatalyst preparation was conducted through sol-gel method and was characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and ultraviolet-visible (UV-vis) spectroscopy. The photocatalytic activity of Ag/ZnO thin film was assessed by measuring the decolorization rate constant of the dyes mixture spectrophotometrically. The chemical structure of each dye influences the photodegradation rate either in mixture or in individual dyes solutions. Several parameters which influence photocatalytic degradation such as catalyst dose, dyes concentrations as well as addition of hydrogen peroxide as an electron acceptor have been studied. The results revealed that these parameters should be optimized to obtain the maximum photocatalytic degradation.