Visible-light-induced peroxymonosulfate activation over ZnFe2O4 fine nanoparticles for ofloxacin degradation.opju

Wide-spread overuse and misuse of antibiotics has led to unintended consequences, and it is necessary to find effective ways to remove antibiotics. In the present study, a visible light response photocatalyst zinc ferrite (ZnFe₂O₄) was synthesized via a hydrothermal synthesis method. The structure, morphology and physicochemical properties of ZnFe₂O₄ were well characterized by X-ray diffraction, Brunauer–Emmett–Teller, Scanning electron microscope, X-ray photoelectron spectroscopy, and Fourier transform infrared spectra analysis. The results showed that ZnFe₂O₄ was circular granular morphology with a particle size of approximately 30–50 nm and the noticeable intergranular agglomeration. The specific surface area, pore volume and pore diameter of ZnFe₂O₄ were determined to be 126.8655 m²/g, 0.2046 cm³/g and 64.5190 Å, respectively, indicating that the ZnFe₂O₄ had a large specific surface area. The enhancement of degradation efficiency of ofloxacin (OFL) by peroxymonosulfate (PMS) under the visible light was evaluated. The results exhibited that the ZnFe₂O₄ achieved the relatively optimum catalytic activity with 80.9% of OFL degradation efficiency in 30 min at pH 6.0 under PMS concentration of 100 mg/L and the corresponding pseudo-first order kinetic<i> </i>constant of OFL degradation was 0.0438 min⁻¹. In addition, the key parameterson (ZnFe₂O₄ dosage, PMS concentration, initial OFL concentration, solution pH, and water matrix) for effective removal of OFL are studied. Moreover, ZnFe₂O₄ exhibited excellent stability and reusability for OFL degradation, and can be used for the degradation of OFL-like antibiotics to solve the increasingly serious problem of antibiotic pollution.

抗生素的广泛过度使用与滥用已引发诸多不良后果，探寻高效去除抗生素的方法迫在眉睫。本研究通过水热合成法制备了一种可见光响应型光催化剂——铁酸锌（zinc ferrite, ZnFe₂O₄）。采用X射线衍射、布鲁诺尔-埃米特-特勒（Brunauer–Emmett–Teller）比表面积分析法、扫描电子显微镜、X射线光电子能谱及傅里叶变换红外光谱分析，对ZnFe₂O₄的结构、形貌与理化性质进行了全面表征。结果表明，ZnFe₂O₄呈类球形颗粒形貌，粒径约为30~50 nm，且存在较为显著的颗粒间团聚现象。测得该催化剂的比表面积、孔容与孔径分别为126.8655 m²/g、0.2046 cm³/g与64.5190 Å，证实其具备较大的比表面积。本研究评估了可见光条件下，过一硫酸盐（peroxymonosulfate, PMS）辅助ZnFe₂O₄对氧氟沙星（ofloxacin, OFL）的降解效能。结果显示，在pH为6.0、PMS投加浓度为100 mg/L的反应体系中，ZnFe₂O₄展现出最优催化活性，30 min内对OFL的降解率可达80.9%，对应的OFL降解准一级动力学常数为0.0438 min⁻¹。此外，本研究考察了影响OFL高效去除的关键参数，包括ZnFe₂O₄投加量、PMS浓度、初始OFL浓度、溶液pH值及水体基质。ZnFe₂O₄对OFL的降解展现出优异的稳定性与重复使用性能，可用于氧氟沙星类抗生素的降解，以应对日益严峻的抗生素污染问题。