Tailoring Oxygen Electrocatalytic Performance via Construction of Iron‐Cobalt Oxides and FeN<sub>4</sub> Sites on Hierarchical Carbon Fibers for Efficient Zinc–Air Batteries
Kexin Wei, Fan Yang, Yang Sun, Chunhui Yu, Junpu An, Guang Ma, Yongfeng Li
Abstract
Abstract The design and fabrication of non‐precious metal materials for bifunctional oxygen electrocatalytic properties with reversible oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) has been a research hotspot in the field of zinc–air batteries. Herein, a hierarchical carbon nanofiber immobilized with iron cobalt oxide particles (FeCoO x ) and Fe‐N x sites catalyst is synthesized through electrostatic spinning and the in situ polymerization of pyrrole coupled with pyrolysis. The FeCoO x /Fe─N─C demonstrates a superior bifunctional electrocatalytic performance (E 1/2 = 0.91 V, η 10 = 350 mV). Liquid zinc–air batteries employing FeCoO x /Fe─N─C exhibit a high power of 184.8 mW cm −2 and more than 580 cycles of stable cycling ability. Additionally, the incorporation of iron cobaltite introduces extra electrons and optimizes the adsorption capacity for oxygen intermediates, effectively boosting the inherent ORR activity. The experimental results illustrate that the special geometrical structure of spinel ferrite provides excellent OER catalytic performance. Theoretical calculations indicate that the incorporation of FeCoO x shifts the d‐band center of iron closer to the Fermi level (E f ), thereby modulating the hybridization between Fe 3d and O 2p orbitals. This work offers an effective approach to constructing coupling catalysts that have single atoms coexisting with oxide particles for efficient bifunctional catalysis.