Nitrogen‐Doped Carbon Dots Modified Fe–Co Sulfide Nanosheets as High‐Efficiency Electrocatalysts toward Oxygen Evolution Reaction

Abstract Developing high‐efficiency and stable oxygen evolution reaction (OER) electrocatalysts is an imperative requirement to produce green and clean hydrogen energy. In this work, the FeCoS y /NCDs composite with nitrogen‐doped carbon dots (NCDs) modified Fe–Co sulfide (FeCoS y ) nanosheets is prepared by using a facile and mild one‐pot solvothermal method. Benefiting from the low crystallinity and the synergistic effect between FeCoS y and NCDs, the optimal FeCoS y /NCDs‐3 composite exhibits an overpotential of only 284 mV at 10 mA cm −2 , a small Tafel value of 52.1 mV dec −1 , and excellent electrochemical durability in alkaline solution. Remarkably, unlike ordinary metal sulfide electrocatalysts, the morphology, components, and structure of the FeCoS y /NCDs composite can be well retained after OER test. The NCDs modified FeCoS y composite with excellent electrocatalytic performance provides an effective approach to boost metal sulfide electrocatalysts for practical application.