Construction of a cathodic MOF/FeOOH heterojunction for boosted Fe(Ⅲ) reduction in electro-Fenton processes

This study developed a self-supported MOF/FeOOH heterojunction cathode without binders for boosted Fe(Ⅲ) reduction in heterogeneous electro-Fenton (EF) processes. The electron transport channels from FeOOH to in-situ grown NH 2 -MIL-88B(Fe) were established through the spontaneous formation of an internal electric field (IEF), which enhanced the electrical conductivity and disrupted the chemical inertness of the Fe(Ⅲ) reduction. The MOF/FeOOH cathode increased sulfamethazine (SMT) removal up to 95.76 %, 2.5 times better than using PTFE as binders. After ten-consecutive degradation experiments, the Fe(Ⅱ) content at cathode surface increased from 39.23 % to 56.73 %. Density functional theory (DFT) calculations and advanced characterization techniques demonstrated the efficient Fe(Ⅲ) reduction and H 2 O 2 activation during the reaction. These results elucidate the promoting effect of modulating the “contact” between the catalyst and current collectors, as to provide a feasible and promising strategy for the development of efficient heterogeneous EF cathodes.