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

Abstract

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.