Synergistic effect of atomically dispersed Fe–Ni pair sites for electrocatalytic reactions to remove chlorinated organic compounds

Electrocatalysis is a promising and environmentally friendly technology for the removal of refractory organics. Diatomic catalysts with an increased number of active sites have emerged with further expansion of the field of atomic catalysts. Here, a metal diatomic FeNi supported graphene (FeNi/N-rGO) catalyst is successfully synthesized. The atomically dispersed Fe and Ni species on graphene is verified by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure spectroscopy. The pollutant degradation efficiencies for the cathode and anode are found to reach 97.6% and 95.8%, respectively, within 90 min in the diatomic catalytic system. According to DFT theoretical calculations, FeNi diatomic catalysts have a lower free energy (ΔG = -0.2 eV), and the higher adsorption energy for the active substance H* is -0.412 eV. This work presents a method for the preparation of high-performance diatomic catalysts and promotes their application in the electrochemical degradation of chlorinated organic pollutants.