Understanding the multiple roles of electrified MXene filter toward boosting the Fenton-like reaction

Abstract

Herein, a comprehensive electrochemical filter was developed that could efficiently activate peroxymonosulfate (PMS) and degrade emerging contaminants in water. Composites of MXene and Fe3O4 nanoparticles were designed to concurrently function as a filter, an electrode, and a highly active Fenton catalyst. When operated with an electric field, the resulting electroactive Fe3O4/MXene nanohybrid filter achieved 97.1 % removal of sulfamethoxazole (SMX) in a recirculation configuration. The superior degradation efficiency was achieved over a broad range of pH values and in a variety of complex and naturally occurring aqueous sources. The flow-through configuration (97.1 %, kobs = 0.0601 min−1) performed significantly better than a traditional batch apparatus (36.3 %, kobs = 0.0074 min−1) because of the advantages of convective mass transfer. The results showed that a radical pathway dominated the SMX degradation process. The essential roles of MXene to support the Fe3O4 catalyst, to increase the dispersion and stability of Fe3O4, and to enhance the catalytic regeneration of the Fe2+ and Fe3+ pairs were studied in depth. The use of electrocatalysis in a filter to activate PMS offers a promising approach to sustainably remediate emerging pollutants.