Preparation of Fe/CuFe₂O₄ embedded in porous carbon composites for removal of tetracycline from aqueous solution

In this paper, the precursors of the target product were prepared using a simple solvothermal method. After pyrolysis of the precursors, a three-dimensional Fe/CuFe2O4@C (referred to as FCC) nanomaterial with a relief texture was successfully prepared, which was employed as a novel catalyst material for activated persulfate (referred to as PS) degradation, tetracycline (referred to as TC), in wastewater. X-ray photoelectron spectroscopy (XPS) revealed that Fe(iii) and Cu(ii) served as the primary active metal ions, while the formation of a surface carbon shell positively influenced electron transfer during catalytic degradation. A comprehensive investigation was conducted to assess the efficiency of FCC nanocatalysts in degrading TC under various conditions. The results demonstrated that the degradation rate of TC in the 100 min range was about 96% at concentrations of 0.2 g L-1 FCC and 1 mmol L-1 persulfate and pH 7. Quenching experiment results and EPR results consistently indicated that both free radical and non-radical pathways involved in TC degradation by FCC nanomaterials, and sulfate radicals, hydroxyl radicals, superoxide radicals and singlet oxygen were identified to be the main active substances. The degradation intermediates were analyzed by liquid mass spectrometry and toxicology. FCC, as a catalyst exhibiting high catalytic activity, demonstrates superior performance in the activated persulfate degradation of TC. The environmental risk associated with the degradation of intermediate products is significantly lower than that of TC itself. FCC holds significant potential for the degradation of antibiotics in wastewater.