Fluorine and sulfur atoms induced N-doped 3D porous carbon catalyzing oxygen reduction in the zinc-air battery

Abstract

Introducing other heteroatom is considered to be a highly effective approach to improve the limited catalytic activity from single nitrogen element doping in nitrogen-doped porous carbon materials. In this work, F and S-modified nitrogen-doped porous carbon (F-S-N-C) is prepared by annealing the assembly material of poly3-fluoro aniline, hydroxyethyl sulfonic acid and g-C3N4, in which the g-C3N4 is employed as template agent and pore-forming agent. A series of characterization techniques indicate that simultaneous doping of F and the S atoms enhance the electron transfer and construct more defects for N-doped 3D porous carbon, resulting in improved electrocatalytic performance. The prepared F and S-cooperated nitrogen-doped porous carbon (F-S-N-C) exhibits significantly improved oxygen reduction reaction electrocatalytic activity in alkaline media with a half-wave potential of 0.808 V. The zinc-air battery (ZAB) with F-S-N-C as the air cathode catalyst demonstrates a peak power density of 167 mW cm−2, which is higher than that of commercial Pt/C (158 mW cm−2). Moreover, the specific capacity of the F-S-N-C-based ZAB reaches to 817 mAh·g−1.