2D MXene (Ti₃C₂T_x) Based Electrodes for the Hybrid Photo-Electro−Fenton Oxidation of Antibiotics

Wastewater containing recalcitrant and toxic pollutants are typically challenging to decontaminate in conventional wastewater facilities. Therefore, there is an urgent need for the development of powerful oxidation processes to ensure their green removal to preserve the water quality in the environment. An efficient and stable catalyst is essential for activating oxidants to produce reactive species for remediating water bodies contaminated by pollutants like antibiotics. In this work, an MXene-based electrode in the form of ferrocene (Fc) functionalized MXene (Fc-Ti₃C₂T_x) (cathode) and TiO₂ derived from MXene (anode) are used as electrodes for hybrid photo-electro-Fenton oxidation of antibiotic Tetracycline. The successful Fc functionalization of Ti₃C₂T_x is confirmed by FTIR, XPS and UV-Vis spectrometry. In addition, a Ti₃C₂/TiO₂ Schottky junction electrode acts as a photoanode and enhances the photo charge carrier separation under UV-light illumination, which boosts the photo-electrocatalysis. The Fc-Ti₃C₂T_x cathode acts as a stable Fe source for the Fenton reactions, and the hybrid oxidation process achieves a removal efficiency of over 90% for degrading antibiotic Tetracycline. The MXene-based electrodes are stable for five cycles with consistent degradation efficiency at different pH. The hybrid oxidation process can be adopted for the treatment of other persistent pollutants for environmental remediation.