Ultraefficient Heterogeneous Electro-Fenton Process Integrated a Natural Dual-Interface Air-Diffusion Cathode for Water Decontamination

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 CBPTFE (1:3) showed that the highest H2O2 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 center dot 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 (similar to 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.