Hierarchical wood cells impose well-textured carbon nanotubes with cobalt single atoms: Bioinspired construction and application in zinc-air battery

The construction of oxygen reduction reaction (ORR) electrocatalysts with well-textured structure and desirable activity remains great challenge for the complicated procedures and poor interface. Herein, inspired by sea anemones, the highly ordered Co-based carbon nanotubes electrocatalysts were elaborately assembled on wood fibers via stoichiometry. The porous cell-wall and abundant oxygen groups in lignocellulosic scaffold impose such preferable structure, in which the Co-based carbon nanotubes with Co single atoms and Co nanoparticles were tuned to possess higher catalytic activity and capture more oxygen species. As expected, the as-prepared electrocatalyst displays outstanding ORR performance with a half-wave potential of 0.9 V. The assembled Zn-air battery using this cathode catalyst shows a high-power density of 196 mW cm-2, superior to the commercial Pt/C catalysts. This work could inspire developing other biomimetic architectures for high-performance energy storage and conversion systems.