Synthesis, characterization and photocatalytic activity of zeolite supported ZnO/Fe2O3/MnO2 nanocomposites

Abstract

ZnO/Fe2O3/MnO2 composites were synthesized by a one-step impregnation of MnO2 with aqueous solution of Fe and Zn nitrate. This was followed by solid state reaction of the as-synthesized nanocomposite with synthetic zeolite to produce the zeolite supported ZnO/Fe2O3/MnO2 fine particles. The structure, morphology, composition and band gap of the composites were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and UV–vis diffuse absorption spectroscopy (UV–vis DAS). Photocatalytic degradation activities of the nanocomposites under visible light irradiation have been evaluated for a model pollutant methylene blue (MB) dye solution as well as on real sewage sample collected from Dire Dawa Textile Industry. Results suggested that the zeolite–ZnO/Fe2O3/MnO2 nanocomposite photocatalyst exhibited a relatively higher efficiency on the photodegradation of both methylene blue (MB) and real sewage sample to the extent of about 93% and 63%, respectively. The improved photodegradation efficiency in the visible region of the supported composite could be due to the sorption characteristics of the zeolite material.