A Strongly Coupled Graphene and FeNi Double Hydroxide Hybrid as an Excellent Electrocatalyst for the Oxygen Evolution Reaction

Cost‐effective electrocatalysts for the oxygen evolution reaction (OER) are critical to energy conversion and storage processes. A novel strategy is used to synthesize a non‐noble‐metal‐based electrocatalyst of the OER by finely combining layered FeNi double hydroxide that is catalytically active and electric conducting graphene sheets, taking advantage of the electrostatic attraction between the two positively charged nanosheets. The synergy between the catalytic activity of the double hydroxide and the enhanced electron transport arising from the graphene resulted in superior electrocatalytic properties of the FeNi‐GO hybrids for the OER with overpotentials as low as 0.21 V, which was further reduced to 0.195 V after the reduction treatment. Moreover, the turnover frequency at the overpotential of 0.3 V has reached 1 s−1, which is much higher than those previously reported for non‐noble‐metal‐based electrocatalysts. A low‐cost and highly active electrochemical catalyst for the oxygen evolution reaction is created by alternatively stacking FeNi double hydroxide cation layers with GO anionic sheets. The advanced performance of the catalyst stems from the intrinsic catalytic activity of the layered FeNi double hydroxide and is boosted by the high electric conductivity of the adjoining graphene sheets.