Dye Contaminants Removal via the Photocatalytic Activity of Metal Oxides-Supported Ag and AgCl Under Visible Light Irradiation

Abstract

One of the major groups of pollutants is formed by dyes existent in industrial wastewater and with increasing worldwide concerns on environmental issues, dye removal has gained significant attention. The Ag/AgCl (silver and silver chloride) counts as a suitable photocatalyst because of its surface plasmon resonances band. In this study, Ag/AgCl nanoparticles were loaded on various supports including TiO 2 (titanium dioxide), La 2 O 3 (lanthanum oxide), and ZnO (zinc oxide) using deposition-precipitation and photoreduction method. The photocatalytic activity of composites was evaluated by removing dye solutions under irradiation of visible light. The results displayed that the photocatalytic activity of Ag/AgCl/TiO 2 and Ag/AgCl/ZnO is higher than Ag/AgCl/ La 2 O 3 , owing to TiO 2 and ZnO partial photocatalytic activity under the radiation of visible light. The Ag/AgCl/ TiO 2 also displayed remarkable photocatalytic activity compared with AgCl/TiO 2 and Ag/TiO 2 due to the coexistence of both active species Ag 0 and AgCl in the composite. The nanocomposites' physicochemical properties were analyzed by X-ray diffraction, Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller, scanning electron microscope, and UV-vis diffusive reflectance spectra mode. This study provides a promising photocatalyst for dye treatment in wastewater using visible light.