Fabrication of FeOCl nanoparticles modified microchannel carbon cathode for flow-through electro-Fenton degradation of refractory organic pollutants

Abstract

This study described an electro-Fenton filter installing a FeOCl nanoparticles loaded microchannel carbon (MC) cathode for rapid removal of refractory organic pollutants. In 120 s of residence time, more than 1.4 mmol/L of H2O2 was produced via oxygen reduction reaction and the active sites were mesoporous carbon in microchannels with the average diameter of 28 μm. FeOCl nanoparticles was the active sites for efficiently activating H2O2 to generate OH and electric field accelerates the cycle of Fe(III)/Fe(II). For the electro-Fenton process taking the phenol solution with initial concentration of 20 mg/L as a target, 98% of phenol and 51% of total organic carbon were removed at a residence time of 450 s. Similar performances were observed for the degradation of atrazine or sulfamethoxazole. The good performance was ascribed to the micrometer-level diffusion distance for O2 and organics and the effective conversion of H2O2 to OH over FeOCl nanoparticles. And it is high-proportioned for OH in microchannels to contact with and oxidize organics. The study demonstrated that the electro-Fenton filter on basis of catalysts loaded microchannel carbon cathodes was a new approach to generate and utilize OH efficiently.