# MOF Derivatives Confined Within Self-Supporting Bamboo Substrates with Hierarchical Porous Architectures for Long-Term Cycling Stability in Zinc–Air Batteries

## TL;DR

A new self-supported electrocatalyst made from bamboo and MOF derivatives shows excellent long-term stability and performance in zinc–air batteries.

## Contribution

A sustainable, self-supported Co-N@CB electrocatalyst is developed using bamboo and ZIF-67 for high-performance zinc–air batteries.

## Key findings

- Co-N@CB exhibits a low OER overpotential of 1.5 V and a potential gap of 0.69 V.
- The material delivers over 10,000 stable cycles in zinc–air batteries.
- The hierarchical porous structure enhances mass transport and active site accessibility.

## Abstract

What are the main findings?
A self-supported Co-N@CB electrocatalyst was prepared using bamboo-derived porous carbon and ZIF-67, integrating biomass sustainability with MOF-derived Co-N sites.The catalyst retains a hierarchical porous structure, providing abundant accessible Co-N active sites for ORRs and OERs.Co-N@CB showed a low OER overpotential (1.5 V) and excellent zinc–air battery performance (ΔE = 0.69 V, >10,000 cycles).

A self-supported Co-N@CB electrocatalyst was prepared using bamboo-derived porous carbon and ZIF-67, integrating biomass sustainability with MOF-derived Co-N sites.

The catalyst retains a hierarchical porous structure, providing abundant accessible Co-N active sites for ORRs and OERs.

Co-N@CB showed a low OER overpotential (1.5 V) and excellent zinc–air battery performance (ΔE = 0.69 V, >10,000 cycles).

What are the implications of the main findings?
Bamboo-derived carbon offers a binder-free, self-supported platform for high-performance electrocatalysts.The hierarchical porous network facilitates mass transport and active site accessibility.The long-term stability and high efficiency of Co-N@CB highlight its promise as a biomass-derived cathode for zinc–air batteries.

Bamboo-derived carbon offers a binder-free, self-supported platform for high-performance electrocatalysts.

The hierarchical porous network facilitates mass transport and active site accessibility.

The long-term stability and high efficiency of Co-N@CB highlight its promise as a biomass-derived cathode for zinc–air batteries.

The relatively poor cycle stability of zinc–air batteries (ZABs) hinders their widespread application, while self-supporting electrode materials have shown great potential in enhancing the cycling stability of ZABs. To construct a self-supporting electrode, bamboo was employed as a sustainable precursor, and a two-step pyrolysis strategy was implemented to integrate ZIF-67-derived catalysts onto a hierarchically porous carbon framework, yielding the composite material Co-N@CB. Benefiting from its structural and electronic advantages, Co-N@CB exhibits outstanding electrocatalytic performance. The overpotential for the oxygen evolution reaction (OER) in alkaline electrolyte is 1.5 V at 10 mA cm−2, with a potential gap (ΔE) of 0.69 V. This material is directly used as the air cathode in ZABs, delivering over 10,000 stable cycles. This excellent cycling stability arises from the strong carbon framework provided by bamboo and the enhanced electrical conductivity achieved through the pyrolytic graphitization of ZIF-67. This study paves the way for further exploration of biomass-based self-supporting electrodes toward high-performance ZABs and emerging micro/nanoscale sensing technologies.