CuFe2O4/CuO magnetic nano-composite activates PMS to remove ciprofloxacin: Ecotoxicity and DFT calculation

In this study, we used the hydrothermal method and high-temperature calcination method to attach CuFe2O4 to CuO for the first time. The (111) plane of CuO and (112) plane of CuFe2O4 formed surface heterojunction, which acts as the interface for adsorbing PMS. Meanwhile, the most stable form of CuFe2O4/CuO, charge transfer and charge density in CuFe2O4/CuO/PMS system are proposed by combining density functional theory (DFT) and transmission electron microscope (TEM). The experimental data from electron spin resonance (ESR) determinations and active species capture demonstrated that both nonradical singlet oxygen (1O2) and active radicals (center dot OH, center dot SO4- ) participate in CIP degradation. The degradation pathways and the intermediates are proposed by Fukui index and liquid chromatography-mass spectrometry (LC-MS). Based on the T.E.S.T program (Toxicity Calculation Software), the bioaccumulation factor, acute toxicity, mutagenicity, and development toxicity of intermediates are proposed. Also, CuFe2O4/CuO demonstrated good reusability and stability. The findings within this work offered deep insights into the mechanisms of organic pollutants degradation via SRAOP over Fe-Cu catalyst. Besides, verification of the experimental results indicated that the CIP removal of 86.67% and the mineralization efficiency of 47.17% under optimal conditions. Finally, chemical oxygen demand (COD) and fluorescence spectra in a three-dimensional excitation-emission matrix (3D EEMs) are used to characterize the potential performance of catalyst CuFe2O4/CuO-500 in medical wastewater.

Automated summary

In this study, CuFe2O4 was attached to CuO using hydrothermal and high-temperature calcination methods. The (111) plane of CuO and (112) plane of CuFe2O4 formed a surface heterojunction, which facilitated the adsorption of PMS. The charge transfer and charge density in the CuFe2O4/CuO/PMS system were investigated using density functional theory (DFT) and transmission electron microscope (TEM). The experimental data showed that both nonradical singlet oxygen (1O2) and active radicals (center dot OH, center dot SO4-) were involved in the degradation of CIP. The degradation pathways and intermediates were proposed using Fukui index and liquid chromatography-mass spectrometry (LC-MS). The study also evaluated the bioaccumulation factor and toxic effects of intermediates using toxicity calculation software. CuFe2O4/CuO demonstrated good reusability and stability. Overall, this study provides valuable insights into the mechanisms of organic pollutants degradation using Fe-Cu catalyst and achieved a CIP removal rate of 86.67% under optimal conditions.