LAUSR

Abstract Heterogeneous photocatalysis is an effective and promising treatment technology for the removal of organic dye compounds in textile wastewater. Hybrid nanostructured semiconductor materials have been extensively applied and received greater attention in the last few decades. In this study, nano structured zinc oxide (ZnO) was doped by silver (Ag) and graphene oxide (GO) nanoparticles to synthesize Ag/GO/ZnO using the sol–gel technique followed by the heat treatment method. The hexagonal wurtzite structure of ZnO as observed by SEM was changed to lump/flake shape after doping with Ag and GO onto the ZnO crystal surface. FTIR confirms the stretching vibration of broad O–H groups with adsorbed H2O molecules. The broad absorption edge of Ag/GO/ZnO nanocomposite shifted to the visible-light region with the reduced band gap energy of 3.22 eV as compared to 3.34 for ZnO. The photocatalytic degradation of methylene blue (MB) dye (15 mgL−1) under 100 W UV irradiation was84.67%, 88.13%, and 97.53%, for ZnO, Ag/ZnO, and Ag/GO/ZnO nanocomposites, respectively, at the same dose of photocatalyst (0.300 g) and pH 11.0for3 h UV irradiation. The best fitted kinetic of photocatalytic studies were showed a pseudo-first-order reaction model and the respective rate constants were found to be 0.0129 min−1, 0.0149 min−1, and 0.5198 min−1, for ZnO, Ag/ZnO, and Ag/GO/ZnO nanocomposites, respectively. The enriched photodegradation activity of Ag/GO/ZnO nanocomposite indicates the potential of the nanocomposite for the treatment of organic pollutants from the textile wastewater.