Tetracycline degradation in the Fe3O4@HKUST-1/persulfate system: properties, activation mechanism, and degradation pathways

Abstract

As a typical antibiotic, tetracycline is ecotoxic and prone to bacterial resistance, producing superbugs and causing a public ecological crisis, thus raising the need to eliminate tetracycline from the aqueous environment. In this work, magnetic catalyst Fe₃O₄@HKUST-1 was prepared for catalyzing the degradation of tetracycline by persulfate. X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry were used to characterize the catalyst, and the results show that the catalyst had good crystallinity and magnetic properties. Tetracycline removal in the Fe₃O₄@HKUST-1/persulfate system reached 84.80%, and the catalyst was easily recovered from the solution due to its good magnetic properties. Mechanism analysis revealed that the non-radical pathway was the main degradation channel in the Fe₃O₄@HKUST-1/persulfate system, and ¹O₂ was the main reactive oxygen species generated from O_v on the surface of the Fe₃O₄@HKUST-1 catalyst. Tetracycline degradation was achieved by hydroxylation, demethylation, decarbonylation, dehydroxylation and the cleavage of C–N bonds. This finding holds significant value in further comprehension of the catalytic activation mechanism of metal–organic frameworks derivatives on persulfate and provides novel ideas for efficient water treatment technology development.