Atomic Dual‐Site Ni/Co‐Decorated Carbon Nanofiber Paper for Efficient O₂ Electrocatalysis and Flexible Zn‐Air Battery

Abstract

The fabrication of flexible catalytic films with isolated single/dual‐atomic sites and their integration in wearable electronics is challenging. Herein, an efficient method to prepare atomically dispersed binary Ni/Co‐decorated flexible carbon nanofiber (NiCo‐CNF) film using formamide‐derived cyano‐specific NiCo‐NC as nanofillers was developed. The optimized Ni1Co1‐CNF catalytic film, having large‐area, high density of adjacent Ni‐N4 and Co‐N4 active sites, and good mechanical properties under repeated bending and release conditions, possessed high catalytic activity towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The ORR/OER potential difference (ΔE10) for Ni1Co1‐CNF at 10.0 mA cm−2 was highly comparable with the Pt/C+RuO2 mixture. In addition, flexible Ni1Co1‐CNF‐assembled Zn‐air battery displayed very good mechanical robustness and cycling stability. Our work may inspire the fabrication of other atomic metal‐decorated films for membrane electrocatalysis.

General synthesis of carbon-guarded cobalt-based nanospheres for oxygen reduction electrocatalysis

“…23 It should be noted that +2 and +3 valence states of Co and Ni can be detected in Ni/Co@NC NPs and Ni/Co@NC, which may be attributed to the oxidation of Ni and Co in the carbon shell. 34 The detailed N 1s spectra (Fig. 2f) reveal the presence of metal-N moieties in Ni/Co@NC NPs and Ni/Co@NC, excluding pyridinic N, pyrrolic N, graphitic N, and oxidized…”