Fe–Nx–C sites decorated porous carbon nanorods with huge specific surface area boost oxygen reduction catalysis for Zn-air batteries

Decorating porous carbon nanomaterials with rich homodispersed metal cluster and heteroatoms can effectively shorten the diffusion pathway of oxygen and expose more active sites, thereby promoting oxygen reduction reaction (ORR). Herein, hierarchical porous carbon nanorods with homodispersed Fe–N x –C active sites are obtained by calcination , etching and ammonia activation of Fe-nitrogenous acid (NTA) coordination polymer nanowires. The obtained Fe-PCNRs-700 as ORR catalysts show the excellent activity with half wave potential (E 1/2 ) of 0.71 V vs. reversible hydrogen electrode (RHE) in 0.5 M H 2 SO 4 and 0.87 V vs. RHE in 0.1 M KOH electrolyte, which owe to its huge specific surface area (1652 m 2 g −1 ), hierarchical pore structure , homodispersed Fe–N x –C active sites and structural defects. Furthermore, using Fe-PCNRs-700 as a cathode catalyst in both liquid and flexible solid Zn-air batteries, and the assembled liquid batteries display the high power density of 161 mW cm −2 and robust charge/discharge stability of 116 h.