Ultraefficient Heterogeneous Electro–Fenton Process Integrated a Natural Dual-Interface Air-Diffusion Cathode for Water Decontamination
Min Chen, Shanshan Guo, Claude Kiki, Dan Qin, Qian Sun
Abstract
The traditional electro–Fenton (EF) process is restricted by pH-sensitive adjustments and high electrical energy input. The novel application of FeOCl coupled natural dual-interface air-diffusion cathode (NAD) and macroporous anode as a highly efficient, reusable, and stable system to the heterogeneous EF process for sulfonamide removal performance was investigated. Our integrated NAD cathode (CB-PTFE) was fabricated by carbon black (CB) and poly(tetrafluoroethylene) (PTFE) with a macroporous free-standing structure, which systematically utilized the dual oxygen supply by natural surface and side diffusion without extra aeration operation. Accordingly, the optimized CB-PTFE (1:3) showed that the highest H 2 O 2 synthesis production reached 5.41 kWh kg –1 . Moreover, the dissolved iron potential and reaction kinetics property of our heterogeneous EF system were comprehensively assessed, quantitatively illustrating the HO • oxidation contributions and reaction activities under the neutral condition. We proposed the possible sulfamerazine (SMR) degradation pathway based on mass spectrometry and theoretical calculation analysis. FeOCl catalyst has a stable crystal structure for further reusable application according to its characterization after multicycle usage. The normalized removal rate per current (antibiotics) of our build system had higher treatment efficiencies (∼5.3 mg min –1 A –1 ) than that of prior heterogeneous EF performances. In summary, the coupled NAD and FeOCl of a heterogeneous EF system is conducive to broadening the prospect for water decontamination application.