Photocatalytic degradation of organic compounds in dye wastewater by Fe3+ doped nano-ZnO/TiO2 composite photocatalyst

Abstract

In this study, a Fe3+ doped ZnO/TiO2 photocatalyst with optimized photocatalytic efficiency has been prepared using the calcination method. The synthesized photocatalyst has been comprehensively characterized using four analytical techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). XRD analysis revealed the presence of TiO2, ZnO, Fe2O3, and carbon in the photocatalyst composition. SEM imaging demonstrated that the particle size of the synthesized photocatalyst is at the nanometer scale. EDS results confirmed the successful doping of Fe3+ into the photocatalyst structure, with the photocatalyst surface exhibiting carbon enrichment. XPS analysis indicated that the combination of ZnO and TiO2 promoted the formation of oxygen vacancies on the TiO2 surface, thereby enhancing photocatalytic efficiency. Optimization experiments revealed that the best photocatalytic performance was achieved when the ratio of Zn (CH3COO)2, TiCl4, FeCl3ꞏ6H2O, and oleic acid was 1:1:0.02:3, with a calcination temperature of 400 ℃. Under these conditions, the Fe3+ doped ZnO/TiO2 photocatalyst exhibited superior photocatalytic efficiency. With the addition of 0.2 wt % Fe3+ to the ZnO/TiO2 photocatalyst, the removal rates of methyl orange reached 90.68% and 97.14% after 4 h of exposure to incandescent lamp and sunlight, respectively.