Silver decorated cobalt carbonate to enable high bifunctional activity for oxygen electrocatalysis and rechargeable Zn-air batteries

Rechargeable zinc–air batteries (ZABs) is primarily driven by the couple of oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Currently, it is still challenging to develop cost-effective, highly efficient, and robust bifunctional catalysts for ZABs. Herein, a novel silver decorated cobalt carbonate (Ag@CoCO 3 ) hybrid catalyst is proposed as the potential bifunctional catalyst to drive OER and ORR for ZABs. Engineering Ag nanoparticles onto the surface of CoCO 3 microsphere not only facilitates the charge transfer, but also modulates the electronic structure, which are beneficial to intrinsic bifunctional activity. As a result, this Ag@CoCO 3 catalyst yields a substantially enhanced bifunctionality compared to the pristine CoCO 3 catalyst. Moreover, the homemade Ag@CoCO 3 based ZABs provides a high peak power density of 146 mW cm −2 , superior to 107 mW cm −2 for CoCO 3 based ZABs and 111 mW cm −2 for commercial Pt/C-IrO 2 based ZABs.