Fabrication of novel Fe2O3/MXene cathode for heterogeneous electro-Fenton degradation of sulfamethoxazole

Abstract

Sulfamethoxazole (SMX) is a widely used antibiotic drug in medical applications resulting in its ubiquity in water and wastewater. Most of the treatment processes are inefficient in destroying SMX in water. The heterogeneous electro-Fenton (EF)process shows promise in the non-selective degradation of antibiotic drugs in water and wastewater. Fe2O3/MXene-x (x is the ferric ion loading) was fabricated on 2D MXene carriers by hydrothermal method. The Fe2O3/MXene-x substrates were characterized by electron microscopic, X-ray, and molecular spectroscopic methods. Degradative products of SMX were identified by free radical quenching and LC-MS measurements. Electron micrographs show that Fe2O3 particulates are uniformly distributed on MXene nanosheets. Fe2O3/MXene-x coated graphite was used as a cathode with titanium anode for in situ generation of H2O2 required to produce free radicals (e.g. ·OH and ·O2–) to destroy SMX. Three possible SMX degradation routes by the electro-Fenton process were proposed. SMX and intermediates are eventually mineralized as CO2 and H2O. The new electrocatalyst shows reduced metal ions leaching and good stability in repeated use cycles. This work offers a new electro-Fenton method to destroy antibiotic drugs in water and wastewater.