Atomically Dispersed Cobalt Trifunctional Electrocatalysts with Tailored Coordination Environment for Flexible Rechargeable Zn–Air Battery and Self‐Driven Water Splitting

Abstract Designing multifunctional catalysts with high activity, stability, and low‐cost for energy storage and conversion is a significant challenge. Herein, a trifunctional electrocatalyst is synthesized by anchoring individually dispersed Co atoms on N and S codoped hollow carbon spheres (CoSA/N,S‐HCS), which exhibits outstanding catalytic activity and stability for the oxygen reduction reaction, oxygen evolution reaction, and hydrogen evolution reaction. When equipped in liquid or flexible solid‐state rechargeable Zn–air batteries, CoSA/N,S‐HCS endows them with high power and energy density as well as excellent long‐term cycling stability, outperforming benchmark batteries based on a commercial Pt/C + RuO2 dual catalyst system. Furthermore, a self‐driven water splitting system powered by flexible Zn–air batteries is demonstrated using CoSA/N,S‐HCS as the sole catalyst, giving a high H2 evolution rate of 184 mmol h−1. The state‐of‐art experimental characterizations and theoretical calculations reveal synergistic cooperation between atomically dispersed CoN4 active sites, nearby electron‐donating S dopants, and the unique carbon support to single‐atom catalysts (SACs). This work demonstrates a general strategy to design various multifunctional SAC systems with a tailored coordination environment.