Highly Curved Nanostructure‐Coated Co, N‐Doped Carbon Materials for Oxygen Electrocatalysis

Nitrogen‐doped graphene could catalyze the electrochemical reduction and evolution of oxygen, but unfortunately suffers from sluggish catalytic kinetics. Herein, for the first time, we report an onion‐like carbon coated Co, N‐doped carbon (OLC/Co‐N‐C) material, which possesses multilayers of highly curved nanostructures that form mesoporous architectures. These unique nanospheres are produced when surfactant micelles are introduced to synthesis precursors. Owing to the combined electronic effect and nanostructuring effect, our OLC/Co‐N‐C materials exhibit high bifunctional oxygen reduction/evolution reaction (ORR/OER) activity, showing a promising application in rechargeable Zn‐air batteries. Experimental results are rationalized by theoretical calculations, showing that the curvature of graphitic carbon plays a vital role in promoting activities of meta‐carbon atoms near graphitic N and ortho/meta carbon atoms close to pyridinic N. A novel onion‐like carbon‐nanosphere‐coated Co, N‐doped carbon (OLC/Co‐N‐C) material was reported for bifunctional oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). OLC/Co‐N‐C exhibits excellent ORR/OER activity and Zn‐air battery performance than Co‐N‐C without OLC structure. Highly curved OLC is beneficial for adsorption of intermediates during ORR/OER process comparing with their analogues in un‐curved graphene.