Mn doping improves in-situ H2O2 generation and activation in electro-Fenton process by Fe/Mn@CC cathode using high-temperature shock technique

Abstract

Fe/Mn@carbon cloth (CC) was successfully fabricated through high-temperature shock (HTS) technique and used as cathode modification in heterogeneous electro-Fenton (hetero-EF) process for methylisothiazolinone (MIT) degradation. The nanocrystalline on Fe/Mn@CC electrode is doped with Fe and Mn oxides and coated with carbon layer, which could markedly enhance the electrocatalysis with high electro-chemical active area and low resistance. Fe/Mn@CC modified cathode can efficiently in-situ produce and activate H₂O₂, showing high electrocatalytic activity to MIT degradation. The 95.2% MIT degradation with in 100 min were achieved under the condition of 30 mA current, 0.75 L min^-1 aeration intensity and initial pH = 3. Based on the CV curves and stability test, the high degradation activity revealed the kinetically beneficial regeneration of Fe^II/Mn^II in Fe/Mn@CC and activation of H₂O₂. The electron transfer between Fe^II/III and Mn^II/III, together with the direct Fe^II/Mn^II regeneration on the cathode, could markedly promote the H₂O₂ utilization, and eventually lead to MIT degradation.

Keywords: H(2)O(2) activation; Heterogeneous elecrto-Fenton; High-temperature shock; Methylisothiazolinone; Synergistic activation.