Earthworm‐Inspired Co/Co3O4/CoF2@NSC Nanofibrous Electrocatalyst with Confined Channels for Enhanced ORR/OER Performance

The rational construction of highly active and durable oxygen‐reactive electrocatalysts for oxygen reduction/evolution reaction (ORR/OER) plays a critical role in rechargeable metal‐air batteries. It is pivotal to achieve optimal utilization of electrocatalytically active sites and valid control of the high specific internal surface area. Inspiration for designing electrocatalysts can come from nature, as it is full of precisely manipulated and highly efficient structures. Herein, inspired by earthworms fertilizing soil, a 3D carbon nanofibrous electrocatalyst with multiple interconnected nanoconfined channels, cobalt‐based heterojunction active particles and enriched N, S heteroatoms (Co/Co3O4/CoF2@NSC with confined channels) is rationally designed, showing superior bifunctional electrocatalytic activity in alkaline electrolyte, even outperforming that of benchmark Pt/C‐RuO2 catalyst. This work demonstrates a new method for porous structural regulation, in which the internal confined channels within the nanofibers are controllably formed by the spontaneous migration of cobalt‐based nanoparticles under a CO2 atmosphere. Theoretical analysis reveals that constructing Co/Co3O4/CoF2@NSC electrocatalyst with confined channels can greatly adjust the electron distribution, effectively lower the reaction barrier of inter‐mediate and reduce the OER/ORR overpotential. This work introduces a novel and nature‐inspired strategy for designing efficient bifunctional electrocatalysts with well‐designed architectures. A novel strategy through gas‐assisted treatment is proposed for fabricating a nanofibrous bifunctional electrocatalyst with confined channels, cobalt‐based heterojunction nanoparticles and enriched N, S heteroatoms. The controllable regulation of the internal channels comes from the spontaneous migration of cobalt‐based nanoparticles with the help of CO2. The synergetic effect of heterojunction, hierarchical nanochannels, and highly‐exposed heteroatoms contributes to efficient ORR/OER electrocatalysis.