Reactivity and Durability of Covalent Organic Frameworks Derived Co-based Hybrid Bifunctional Electrocatalysts for Zinc-Air Batteries

Developing bifunctional non-precious metal electrocatalysts of superior reactivity and durability is essential. Herein, we report a class of phthalocyanine-based covalent organic frameworks as self-sacrificial precursors derived Co-based hybrid electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The fabricated Co-COFs/CNT-700 catalysts displayed highly efficient ORR properties with a half-potential of 0.83 V, while its half-wave potential in alkaline solution at a current density of 10 mA cm-2 is 1.70 V in the OER test, reflecting exceptional OER activity. Moreover, zinc-air batteries assembled with Co-COFs/CNT-700 catalysts exhibit a marginally higher power density (114 mW cm2) than traditional Pt/C-IrO2 batteries in an air atmosphere, along with an enhanced cycling stability (5.1 % potential loss after 65 h). This work may pave a facile and efficient approach for fabricating electrocatalytic materials with controllably introduced metals and heteroatoms. A class of Co-based hybrid catalysts (Co-COFs/CNTs-X) based on few-layer phthalocyanine COFs/CNT composites were synthesized for oxygen electrocatalysis, in which Co-COF/CNT-700 exhibited excellent ORR and OER activities. Furthermore, it was used as the air cathode in zinc-air batteries and showed comparable performance with Pt/C-IrO2 as well as enhanced cycling stability. This study paves a convenient and efficient way to fabricate electrocatalytic materials with controllable introduction of metals and heteroatoms. image