Ultralong nitrogen/sulfur Co‐doped carbon nano‐hollow‐sphere chains with encapsulated cobalt nanoparticles for highly efficient oxygen electrocatalysis

Abstract The development of simple and effective strategies to prepare electrocatalysts, which possess unique and stable structures comprised of metal/nonmetallic atoms for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), is currently an urgent issue. Herein, an efficient bifunctional electrocatalyst featured by ultralong N, S‐doped carbon nano‐hollow‐sphere chains about 1300 nm with encapsulated Co nanoparticles (Co‐CNHSCs) is developed. The multifunctional catalytic properties of Co together with the heteroatom‐induced charge redistribution (i.e., modulating the electronic structure of the active site) result in superior catalytic activities toward OER and ORR in alkaline media. The optimized catalyst Co‐CNHSC‐3 displays an outstanding electrocatalytic ability for ORR and OER, a high specific capacity of 1023.6 mAh g_Zn⁻¹, and excellent reversibility after 80 h at 10 mA cm⁻² in a Zn‐air battery system. This work presents a new strategy for the design and synthesis of efficient multifunctional carbon‐based catalysts for energy storage and conversion devices.