Unveiling the activity origin of electrocatalytic oxygen evolution over isolated Ni atoms supported on a N-doped carbon matrix

Abstract

Exploring highly efficient electrocatalysts for the oxygen evolution reaction (OER) and unveiling their activity origin are pivotal for energy conversion technologies. Herein, atomically distributed Ni sites over a N-doped hollow carbon matrix are reported as a promising electrocatalyst for OER in alkaline conditions. Significantly boosted activity is observed after the decoration of the active Ni sites with well-controlled coordination geometry. Results of X-ray absorption spectroscopy investigation and density functional theory (DFT) calculation reveal that the effective electronic coupling via the Ni-N coordination can move down the Fermi level and lower the adsorption energy of intermediates, thus resulting in the facilitated OER kinetics.