Bio-assisted synthesis of cobalt-based heterostructures in carbon nanobelts for enhanced oxygen catalysis in Zn-air battery

Abstract

The delicate design and fabrication of transition metal-based heterostructures with abundant active sites are a crucial issue for achieving superior electrocatalytic properties. In this work, we introduce a novel bio-assisted strategy for assembling cobalt-based heterostructures on nitrogen and phosphorus codoped carbon nanobelts, which serve as highly efficient bifunctional oxygen catalysts. The fungus of Rhizopus is utilized to encapsulate the Co-CoTe within the in-situ formed nitrogen and phosphorus codoped carbon nanotubes (NPCNT), resulting in hairy nanobelts with a porous structure and excellent flexibility. Both experimental and theoretical analyses results reveal the superior geometric configuration, electronic structure, and the low energy barrier of the bio-Co-CoTe@NPCNT nanobelts. Benefitting from these advantages, the bio-Co-CoTe@NPCNT nanobelts demonstrate rapid kinetics, impressive catalytic performance, and high durability in both oxygen evolution and reduction (OER/ORR) reactions. The aqueous zinc-air batteries (ZAB) employing the prepared bio-Co-CoTe@NPCNT nanobelt cathode exhibit the stable cycling properties and good reliability. Furthermore, the solid-state ZAB demonstrates high reliability, pliability, and durability under various deformations.