Co3O4–CuO bimetallic catalyst activated PMS to degrade LEV in wastewater: the existence of dual degradation mechanisms

Abstract

In this study a Co₃O₄–CuO bimetallic catalyst (referred to as CCO) was synthesized using the co-precipitation method. The structure of the catalyst was determined and analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The results provide evidence that the CCO bimetallic catalyst has been successfully prepared, and the surface was rich in oxygen vacancies (Ov). The effects of different factors on the removal of levofloxacin (LEV) by the CCO activated peroxymonosulfate (PMS) system were compared. In the CCO/PMS reaction system, LEV degradation was observed at 85% within 10 minutes and reached a total of 97% within an hour when the CCO dosage was maintained at 0.2 g L⁻¹, the PMS dosage was at 0.8 g L⁻¹, and the pH level was kept constant at 7. It was also proven that CCO could efficiently degrade LEV (degradation rate over 83%) within a wide pH range (pH = 3–11). Quenching studies demonstrated the predominant role of singlet oxygen (¹O₂) in LEV degradation, alongside contributions from sulfate (SO₄˙⁻) and hydroxyl (˙OH) radicals. The catalyst could stably and efficiently degrade LEV and most common antibiotics, demonstrating great potential for practical wastewater treatment.