Preparation of\nHierarchical Porous Fe/N Codoped Carbon\nNanosheets as Oxygen Reduction Reaction Electrocatalysts for the Zinc-Air\nBattery

In recent years, Fe–N–C materials have\nbeen considered\nas feasible substitutes for platinum-based catalysts to enhance the\noxygen reduction reaction (ORR). However, Fe–N–C catalysts\nstill have specific problems, including poor inherent activity, restricted\navailability of active sites, and inferior stability. This work presents\na simple and efficient method for synthesizing Fe/N codoped hierarchical\nporous carbon nanosheets using one-step pyrolysis. The optimized Fe–N–C\n900 catalyst exhibits excellent ORR performance with an onset potential\nof 0.958 V and half-potentials of 0.885 V in an alkaline medium, surpassing\nthose of the commercial Pt/C catalyst. In addition, the optimal catalyst\ndemonstrated improved stability and great resistance to methanol.\nFurthermore, the zinc-air battery constructed from Fe–N–C\n900 shows a remarkable power density of 163.65 mW cm<sup>–2</sup> and a specific capacity of 807.80 mA h g<sub>Zn</sub><sup>–1</sup>. The electrochemical stability and cycle stability were proven to\nexceed 400 h at a current density of 5 mA cm<sup>–2</sup>.\nThis study offers valuable insights for the development of highly\nefficient and stable ORR catalysts in the clean energy field.