High-Efficient photocatalytic degradation of Levofloxacin via a novel ternary Fe2O3/CeO2/ZnO Heterostructure: Synthesis Optimization, Characterization, toxicity assessment and mechanism insight

Abstract

Considering the serious problem of lack of freshwater worldwide and the effectiveness of the photocatalysis process in water purification, we prepared a novel Ternary Fe2O3/CeO2/ZnO photocatalyst toward degradation of Levofloxacin (LEF) antibiotic. In this study, the CeO2 was synthesized through the hydrothermal route and the nanocomposite was prepared using a simple-impregnation method. Then the synthesized materials with various weight percentages 5 %FeCe (10, 20, 30 and 40 %) on the ZnO were completely characterized in the aspects of structural, morphological and optical properties with the aid of XRD, XPS, BET, TEM, SEM, EIS, ESR, Band-gap, Photocurrent, Mott Schottky, etc. The XPS analysis depicts the successful construction of required bonds among FeCe/ZnO materials. The enhancement of LEF decomposition was investigated utilizing RSM-CCD method, considering factors such as the amount of catalyst used, irradiation time, pH levels, and the initial concentration of LEF. The trapping experiments of free radicals highlight the significant contributions of the •OH and •O2– radicals. A notable degradation rate of 98.9 % was achieved under optimal operational conditions, which included catalyst dosage of 0.69 g/L, irradiation period of 83.64 min, initial LEF concentration of 37.9 mg/L, and pH of 6.18. Furthermore, the findings of EIS, photocurrent, and Mott-Schottky analyses allowed for proposing a suitable charge transfer mechanism and demonstrated effective separation of photo-generated electron-hole pairs. Additionally, LC-MS analysis was utilized to elucidate the intermediate products generated during the photodegradation of LEF, leading to the proposal of plausible degradation pathways. The exceptional efficiency of the 30FeCe/ZnO photocatalyst highlights its promising potential for the efficient treatment of persistent organic pollutants on a large scale in wastewater treatment plants.