Cobalt-carbon nanocage modified carbon foam as the efficient catalyst towards oxygen reduction reaction and high-performance zinc-air battery.

Inspired by the space mud of artificial children's toy, a shape designable carbon foam (Co-NCF) is developed. This carbon foam is endowed with ferromagnetism, oil-absorption, lightweight and has a three-dimensional network intertwined with cobalt dots, nitride graphene and fibrous carbon. Those cobalt dots are actually encapsulated in a carbon nanocage, and then modified on the nitride graphene nanosheets. The Co–N bonds are generated at the core-shell interfaces of the cobalt-carbon nanocages. The network structure of carbon foam is beneficial to the mass and charge transfer of the electrocatalysis, and the cobalt-carbon nanocages further enhance the activity of oxygen reduction reaction (ORR). These advantages endow the as-prepared Co-NCF with the excellent ORR activity and outstanding catalytic stability that exceeding the commercial Pt/C catalyst. Applied as the electrocatalyst to the zinc-air battery, Co-NCF achieves good applicability with a high output power density and discharge capacity. This work provides a novel low-cost strategy for the development of material architectures and the high-performance ORR electrocatalysts. Image 1 • Novel strategy from cellulose space-mud to designable multifunctional carbon foam. • A 3D-network intertwined with cobalt dots, N-doped graphene and fibrous carbon. • The cobalt-carbon nanocages present in Co-NCF further boost the activity of ORR. • The Co-NCF catalyst is endowed with the excellent ORR activity and good stability. • The Co-NCF catalyst is applied to zinc-air battery and expresses good applicability. [ABSTRACT FROM AUTHOR]