Atomic cobalt catalysts for the oxygen evolution reaction†
Development of high-efficiency single-atom catalysts (SACs) for the oxygen evolution reaction (OER) is challenging. Herein, we report a facile annealing strategy to construct an atomically dispersed cobalt- and nitrogen-codoped graphene catalyst for high-efficiency OER. The as-prepared 0.7-Co@NG-750 electrocatalyst requires an ultra-low onset overpotential of approximately 210 mV on a glassy carbon electrode in both 1.0 M KOH and 0.1 M KOH solutions. The density functional theory (DFT) calculations reveal that the theoretical overpotential on Co–N4 and Co–N2C2 sites is 0.41 and 0.53 V, respectively, and these might be efficient active sites for electrocatalytic water oxidation.