Bifunctional Electrocatalysts (Co9 S8 @NSC) Derived from a Polymer-metal Complex for the Oxygen Reduction and Oxygen Evolution Reactions

Abstract Bifunctional catalysts for water electrolysis are important for renewable and clean energy transformation processes like fuel cells, lithium−oxygen batteries, and so forth. Despite tremendous efforts, developing efficient bifunctional electrocatalysts with low cost and long‐term durability remains a great challenge. Herein, the synthesis of Co 9 S 8 nanocrystals encapsulated in nitrogen/sulfur‐doped mesoporous graphitized carbon derived from a polymer−metal complex is reported, which exhibit similar electrocatalytic activity and superior stability for water‐splitting reactions (oxygen reduction/oxygen evolution). The remarkable electrochemical properties are mainly attributed to the synergetic effects between Co 9 S 8 , heteroatoms and graphitized carbon in alkaline medium, especially for the oxygen evolution reaction. The present strategy to fabricate Co 9 S 8 nanocrystals in nitrogen and sulfur doped carbon using a single‐source precursor offers many prospects in developing highly effective electrocatalysts in rechargeable metal−air batteries.