MIL-53(Fe) derived magnetic CuFe₂O₄/Fe₂O₃ composite for catalytic oxidation of sulfamethoxazole via peroxymonsulfate activation

Design of metal–organic framework (MOF) derived metal oxides is an effective approach for environmental remediation. The current study describes the fabrication of MIL-53-derived perforated CuFe₂O₄/Fe₂O₃ using a facile, one-step, post-thermal solid-state approach by varying Cu/Fe ratios. Herein, the release of CO₂ and H₂O during the thermal treatment facilitates the incorporation of Cu²⁺ onto the Fe₂O₃ structure, forming a perforated hollow CuFe₂O₄/Fe₂O₃ composite via an in-situ ion-exchange mechanism. The optimised catalyst CF-0.5 displays a high degradation efficiency for the removal of sulfamethoxazole (SMX) by heterogeneous activation of peroxymonsulfate (PMS), ascribing to the better textural, morphological, and elemental properties of the novel catalyst. Important reaction parameters such as pH, catalyst loading, PMS dosage, pollutant kind and concentration, and reaction temperature are further optimised to develop a cost-effective catalytic system. The magnetically recoverable catalyst outlines a high stability rate, and only a 9 % efficiency loss is observed even after the fourth cycle. Reactive oxygen species (ROS) are identified by electron paramagnetic resonance spectroscopy (EPR) and their roles are determined by performing quenching experiments. In the end, a detailed study of the mineralisation ability and reaction intermediates is performed and possible pathways for the degradation mechanism are proposed. This study not only introduces a facile approach for the fabrication of MOF-driven nanomaterials but provides insights into the removal of emerging contaminants such as SMX.