Bimetal Covalent Organic Frameworks/Carbon Nanotube-Derived Iron-, Cobalt- and Nitrogen-Codoped Catalysts for Efficient Oxygen Electrocatalysis and Zinc-Air Batteries

The preparation and research of high-efficient bifunctional non-noble metal electrocatalyst is the key to bolster the further development of Zinc-air batteries. Herein, we account the fabrication of a kind of Fe/Co/N-codoped catalysts (CoFe-COFbpda/CNT-X) derived from bimetallic COFs/carbon nanotube composites toward both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The bipyridine were optioned and indited in the COFs to anchor metal ions (Fe), which can effectively keep back the migration and aggregation of metal ions during pyrolysis. The obtained CoFe-COFbpda/CNT-700 exhibits higher ORR catalytic performance, with half-wave potential reaches 0.862 V and the limiting current density is 5.12 mA cm(-2) in 0.1 M KOH solution. For OER, the CoFe-COFbpda/CNT-700 at the current density of 10 mA cm(-2) is as low as 1.67 V and smaller Tafel slope compared to most oxygen electrocatalysts in 0.1 M KOH solution. Furthermore, the application of CoFe-COFbpda/CNT-700 as the air cathode in Zinc-air battery displays outstanding property and enhanced cycling stability compared with Pt/C-IrO2.

Automated summary

The preparation and research of high-efficient bifunctional non-noble metal electrocatalyst is crucial for the further development of Zinc-air batteries. In this study, a Fe/Co/N-codoped catalyst (CoFe-COFbpda/CNT-X) derived from bimetallic COFs/carbon nanotube composites was fabricated for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The obtained catalyst showed excellent catalytic performance in both ORR and OER, as well as enhanced cycling stability as an air cathode in Zinc-air battery compared to Pt/C-IrO2.