Biomass chitosan-derived Co-induced N-doped carbon nanotubes to support Mn3O4 as efficient electrocatalysts for rechargeable Zn-air batteries

Exploring efficient and low-cost electrocatalysts toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is extremely desirable for the commercial application of rechargeable Zn-air batteries. Herein, we developed a facile pyrolysis and hydrothermal method for in situ immobilizing Mn3O4 onto chitosan-deriving Co-induced N-doped carbon nanotubes (Mn3O4/NCNTs@Co). The obtained Mn3O4/NCNTs@Co nanohybrid showed excellent activity for oxygen-reversible electrocatalysis with a half-wave potential (E-1/2) of 0.85 V and a potential of 1.53 V at 10 mA cm(-2). Furthermore, a homemade zinc-air battery with Mn3O4/NCNTs@Co catalyst showed a high open-circuit voltage (OCV) of 1.46 V and excellent cycling stability of nearly 1100 cycles at 5 mA cm(-2). The outstanding electrocatalytic activities are comparable to those with commercial noble metal catalysts, ascribed to the synergistic integration between the Co, Mn3O4, and conductive carbon matrix. This study provides a promising route for the scalable preparation of biomass-derived efficient metallic compound-carbon-based ORR/OER electrocatalysts.

Automated summary

In this study, a facile pyrolysis and hydrothermal method was developed to immobilize Mn3O4 onto chitosan-deriving Co-induced N-doped carbon nanotubes. The resulting Mn3O4/NCNTs@Co nanohybrid exhibited excellent activity for oxygen-reversible electrocatalysis and showed promising potential for the commercial application of rechargeable Zn-air batteries.