A rational self-sacrificing template strategy to construct 2D layered porosity Fe3N-N-C catalyst for high-performance zinc-air battery

Abstract

Two-dimensional (2D) layered carbon with high electrochemically surface area and conductivity has risen as a prospective supporter to construct transition metal-nitrogen-doped carbon (M-N-C) catalysts. Graphene and graphene-like layered templates can produce continuous large surface areas, while restacking and low porosity issues usually limit the in-plane ion diffusion and accessibility of internal sites. Constructing porous structures by removing their 2D templates increases the approachability of internal active areas. However, the tedious template stripping process will not only require dangerous acids/alkali but damage the original structure and catalytic activity. Thus, it is highly desired to use the self-sacrificial template to take advantage of the template method and avoid its trouble. Herein, we adopted layered graphite phase carbon nitride (g-C3N4) as a self-sacrificing template, which can decompose into gaseous products containing C- and N- in pyrolysis reaction to construct the layered, porous morphology and provide an enhanced N configuration. The prepared Fe3N-N-C-50 catalyst presents a more positive E1/2 of 0.885 V, and lower Tafel slop than the Pt/C-20%. Furthermore, the Fe3N-N-C-50 based zinc-air battery (ZAB) shows excellent discharging performance and durability in 210 h. The manufactured flexible ZABs exhibit good flexibility and durability in different winding conditions.