Double-potential electro-Fenton: A novel strategy coupling oxygen reduction reaction and Fe 2+/Fe 3+ recycling

摘要

In general, the electro-Fenton degradation potential is set according to the optimal H2O2generation potential without considering Fe2+/Fe3+electrocatalytic recycling, resulting in high-energy consumption and iron sludge. In this work, a novel double-potential strategy was provided by alternately applying the optimal H2O2generation potential and Fe2+/Fe3+recycling potential during the degradation process. The double-potential method showed a coordination ofin-situH2O2generation by oxygen reduction reaction (ORR) and Fe2+/Fe3+recycling. EPR detection indicated that more hydroxyl radicals were produced during the double-potential process compared with the one achieved by constant potential. An outstanding DMP mineralization rate of 94.0% was achieved within 30?min and corresponding energy consumption was 0.762?×?104?kJ?kg?TOC?1while the constant potential method reached 73.4% at ?0.5?V and corresponding energy consumption was 1.54?×?104?kJ?kg?TOC?1.