Silver/silver halide supported on mesoporous ceria particles and photo-CWPO degradation under visible light for organic compounds in acrylonitrile wastewater

Abstract

Silver/silver halide supported on ordered mesoporous ceria particles (Ag/AgCl/CeO₂) were rapidly prepared by microwave-assisted soft template method, deposition precipitation method and photoreduction method, using cerium nitrate and silver nitrate as raw materials and block copolymer F127 as a template. The morphology, structure and chemical composition of the catalyst were characterized by XRD, SEM, EDS, TEM, N₂ adsorption–desorption and UV-Vis Drs. Catalytic wet peroxide system assisted with visible light photocatalysis (photo-CWPO) was conducted to investigate the performance of organics degradation by Ag/AgCl/CeO₂ as a catalyst in acrylonitrile wastewater. The results showed that the Ag/AgCl/CeO₂ prepared has an ordered mesoporous structure, Ag and AgCl are formed on the surface of CeO₂, with a specific surface area of 302.6–336.2 m² g⁻¹ and the average pore size is 8.04–8.90 nm. There is a strong absorption in the visible region and a band gap of 2.9 eV. The Ag/AgCl/CeO₂ catalyst has higher catalytic performance in the photo-CWPO system than in the CWPO system alone. Ag loading, catalyst and H₂O₂ dosage, and pH value can affect the COD removal. When the concentration of COD in acrylonitrile wastewater was 500 mg L⁻¹, the amount of catalyst was 200 mg, the amount of H₂O₂ (30%) was 8 mL, and the reaction time was 60 min, the COD removal reached 90%.