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.