Efficient degradation of antibiotics mixture in a solar photoelectro-Fenton system using CuFe2O4@GO@MIL-100(Fe): Boosting efficiency via enhanced charge separation

The efficiency of Fenton-based electrochemical catalysts depends on the rapid regeneration of Fe2+, which is crucial for producing hydroxyl radicals in the Fenton reaction. Integrating photocatalysis with these processes using photoactive nanomaterials enhances Fe2+ regeneration, boosting overall performance. This study explores heterogeneous solar photoelectro-Fenton (HSPEF) treatment using CuFe2O4@GO@MIL-100(Fe) as a sustainable catalyst to improve the removal of pharmaceuticals from water. The catalyst was synthesized by a simple method using CuFe2O4 as a precursor and GO as an electron transfer bridge, derived from MIL-100(Fe) layers. This composite was employed as a photoactive catalyst in the hybrid solar photoelectro-Fenton/photocatalysis process for the efficient degradation of a mixture of antibiotics, including cefadroxil, ciprofloxacin, sulfamethoxazole, and chloramphenicol. Morphology, crystal structure and chemical composition of the catalyst were preliminarily characterized using scanning electron microscopy, Raman spectroscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Optical properties of the catalyst were evaluated using Diffuse Reflectance Spectroscopy. The characterization conducted confirmed the successful formation of the ternary CuFe2O4@GO@MIL-100(Fe) catalyst. The degradation results demonstrated that the incorporation of GO significantly enhanced the process, achieving a 100 % removal efficiency within 50 min. The influence of key operational parameters, including pH, applied current, and nanomaterial concentration, was systematically evaluated. Potential catalytic degradation mechanisms were proposed based on radical quenching experiments. Additionally, the magnetic properties of the composite enabled its efficient separation using an external magnetic field, facilitating catalyst recovery and reuse. The catalyst exhibited excellent recyclability, maintaining high removal efficiency over five consecutive cycles.