A recyclable polydopamine-functionalized Fe3O4/PDA-Fe3+ catalyst for the activation of peroxymonosulfate toward enhanced degradation of tetracycline

BACKGROUND

The increasing usage of tetracycline in antiviral therapy has caused severe aqueous water contamination, and advanced oxidation processes based on sulfate radicals have been recognized as an effective technique for degrading this antibiotic into harmless small molecules.

RESULTS

Herein, a strategy based on dopamine self-polymerization was utilized to synthesize the magnetite/polydopamine-ferric ion (Fe₃O₄/PDA-Fe³⁺) catalyst with excellent magnetism and abundant surface functional groups. This catalyst exhibited high performance in activation of permonosulfate for tetracycline degradation. The surface properties and chemical composition of this catalyst were characterized by scanning electron microscopy, X-ray diffraction, vibrating sample magnetometer, Fourier transform infrared and X-ray photon spectroscopy, which indicated that Fe₃O₄/PDA-Fe³⁺ could active permonosulfate to generate strong oxidizing free radicals for catalytic degradation of tetracycline. Beside its excellent catalytic activity, Fe₃O₄/PDA-Fe³⁺ also exhibited superior structural stability and reusability, and this catalyst could be simply recycled from solution using an external magnet. Additional quenching experiments and chemical environment analysis confirmed that hydroxyl, sulfate and superoxide anion radicals, singlet oxygen and surface-adsorbed oxygen contributed significantly to degradation of tetracycline.

CONCLUSION

This work proved that dopamine self-polymerization strategy could be used as an effective route to produce highly active and structurally sturdy catalysts for the degradation of organic pollutant. © 2024 Society of Chemical Industry (SCI).