Highly efficient heterogeneous electro-Fenton degradation of organic pollutants using a FeNi-OH/NF cathode

The electro-Fenton (EF) technology provided a promising way to degrade organic pollutants by in-situ producing H2O2 and decomposing it into hydroxyl radicals (center dot OH). However, the degradation rate is restricted by the two -electron oxygen reduction reaction (ORR) rate of H2O2 generation and the production efficiency of center dot OH, and the efficient EF cathode is important. Herein, we designed an efficient heterogeneous EF system with a Fe-doped beta-Ni (OH)2 nanosheets/nickel foam (FeNi-OH/NF) cathode for phenol removal in water. FeNi-OH enhanced the electrochemically active area for H2O2 production and produced center dot OH for pollutant degradation. The FeNi-OH/NF cathode demonstrates excellent heterogeneous EF catalytic activity with a degradation efficiency of phenol (99.4%) and total organic carbon (67.4%) in 2 h. The experiments and density functional theory (DFT) calcu-lations further confirmed that the Fe-doped beta-Ni(OH)2 on the nickel foam enhanced H2O2 adsorption and accelerated Fe3+/Fe2+ circulation, promoting the reaction of H2O2 with Fe2+ to produce center dot OH for phenol degradation. This study provides a novel and efficient heterogeneous EF cathode for accelerating pollutant degradation securely and quickly.