Metal‐Organic Framework Supported Dual Functional Air Cathode Carbon Nanofiber as an Efficient Electrocatalyst for the Rechargeable Zinc‐Air Batteries

Abstract Fabricating efficient bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) remains a major challenge in renewable energy technologies. To develop a high‐performance bifunctional electrocatalyst, a strategy combining electrospinning, in‐situ synthesis, and carbonization was employed to fabricate three‐dimensional (3D) flexible porous carbon nanofiber electrocatalysts. A thermal treatment approach using in situ grown metal‐organic frameworks (MOFs) is employed to synthesize highly porous, nitrogen‐doped carbon nanotubes (N‐CNTs) embedded with cobalt nanoparticles, along with hydroxy‐functionalized boron nitride nanosheets (HO‐BN) uniformly incorporated into electrospun carbon nanofibers (CNFs), forming a composite (N‐CNT@MOF‐Co/HO‐BN/CNFs). Thus, the synthesized electrocatalyst reveals exceptional bifunctional catalytic performance for both the ORR and OER. This is indicated by a small potential gap of 0.70 V between the ORR half‐wave potential and the OER potential at a current density of 10 mA cm −2 , a value that is competitive with that of the mixed commercial noble catalyst made up of 30% Pt/C and IrO 2 . The rechargeable zinc‐air battery is designed to exhibit a noteworthy open‐circuit voltage of 1.448 V, impressive power density (142.9 mW cm −2 ), and energy density (700 Wh kg −1 ). This research introduces a methodology for the synthesis and construction of high‐performance bifunctional electrocatalysts.