Space‐Confined Growth of Co₉S₈ Nanoparticles in Covalent Organic Framework‐Derived Porous Carbon for Efficient Bifunctional Oxygen Electrocatalysis

Abstract Fine regulation of the physicochemical structure of carbon‐based electrocatalysts to optimize the adsorption energies of oxygen intermediates is critically important to enhance the reaction kinetics of the oxygen evolution/reduction reaction (OER/ORR) but remains a huge challenge. Herein, nano‐space confined growth of Co₉S₈ nanoparticles (NPs) in porous carbon is realized through an in situ confined growth strategy by using thiol‐chains functionalized COF (COF‐S‐SH) as a confined template. COF‐S‐SH is used as binding sites to immobilize Co ions to improve the interaction between metal nanoparticles (NPs) and carbon skeletons, and simultaneously serves as a confined void to avoid the aggregation metal NPs. Impressively, as an efficient bifunctional catalyst, the resulting Co₉S₈/COF‐S₈₀₀ shows significantly enhanced oxygen electrocatalysis with a small OER‐ORR voltage gap of 0.76 V, vastly superior to that of pristine COF‐S₈₀₀. Furthermore, the assembled Zn–air battery with Co₉S₈/COF‐S₈₀₀ catalyst displays a high peak power density of 181.5 mW cm⁻² and great durability over 60 h charge–discharge cycles.