Polypyrrole Template-Assisted Synthesis of Tubular Fe-NC Nanostructure-Based Electrocatalysts for Efficient Oxygen Reduction Reaction in Rechargeable Zinc–Air Battery

Abstract

One-dimensional metal/N-doped carbons have exhibited promise for use as efficient catalysts of the oxygen reduction reaction (ORR). In this work, Fe,Ndoped carbon nanotubes (Fe-NC@NCNT) are developed by pyrolyzing the precursor/template of a polypyrrole (PPy) nanotube-anchored Fe/Zn-based zeolite imidazole framework. Thanks to the hierarchical tubular nanostructure, high electronic conductivity, and abundant Fe-based species (Fe-N x sites and Fe/Fe 3 C nanoparticles), the designed electrocatalyst exhibits a catalytic property comparable to that of commercial Pt/C. Specifically, the Fe-NC@NCNT catalyst undergoes a fourelectron ORR pathway with an onset potential of 0.96 V and a half-wave potential of 0.88 V versus reversible hydrogen electrode, a small Tafel slope of 60.0 mV dec −1 , remarkable long-term cycle durability, as well as strong alcohol tolerance in an alkaline electrolyte. When applied to the air-electrode catalyst of rechargeable zinc−air batteries, the

Integration of Fe2N Nanoparticles and FeCo Alloys into N-Doped Carbon Nanotubes as Efficient Oxygen Catalysts for Rechargeable Zn–air Batteries

“…(a) LSV curves of CoFe/Fe 2 N@N-CNTs and Pt/C + RuO 2 in the full OER/ORR region; (b) a schematic illustration of the liquid ZABs; (c) open-circuit voltage for aqueous ZABs based on CoFe/Fe 2 N@N-CNTs and Pt/C+RuO 2 , respectively; (d) cyclic performance of rechargeable ZABs at different current densities for CoFe/Fe 2 N@N-CNTs and Pt/C + RuO 2 ; (e) discharge curves and the corresponding power density plots of CoFe/Fe 2 N@N-CNTs and Pt/C + RuO 2 ; (f) specific discharging capacities for primary ZABs assembled by CoFe/Fe 2 N@N-CNTs and Pt/C + RuO 2 at the current density of 10 mA cm –2 ; (g) galvanostatic cycling performance for CoFe/Fe 2 N@N-CNTs and Pt/C + RuO 2 at 10 mA cm –2 ; and (h) open circuit voltage (OCV) and power density comparison for CoFe/Fe 2 N@N-CNTs and other transition-metal-based catalysts. − …”