Surface Reconstruction Facilitated by Fluorine Migration and Bimetallic Center in NiCo Bimetallic Fluoride Toward Oxygen Evolution Reaction

are attributed to the low aqueous stability of coordination. The theoretical researches predicte that transition metal fluorides should have a strong tendency to electrochemical reconstruction. Therefore, based on the observations on their electrochemical behavior, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and bode plots, it is further demonstrated that surface reconstruction occurred during the electrochemical process, meanwhile a significant increase of electrochemically active area, which is created by F migration, are also directly observed. Additionally, DFT calculation results show that the electronic structure of the catalysts is modulated by the bimetallic centers, and this reconstruction helps optimizing the adsorption energy of oxygen-containing species and improves OER activity.