FeCo alloy entrapped in N-doped graphitic carbon nanotubes-on-nanosheets prepared by coordination-induced pyrolysis for oxygen reduction reaction and rechargeable Zn-air battery

Abstract

Oxygen reduction reaction (ORR) on cathode severely suffers from sluggish kinetics in zinc-air batteries. Therefore, substantial efforts have been made to prepare advanced electrocatalysts for facilitating the ORR. Herein, we synthesized FeCo alloyed nanocrystals entrapped in N-doped graphitic carbon nanotubes on nanosheets (FeCo-N-GCTSs) by 8-aminoquinoline coordination-induced pyrolysis, whose morphology, structures, and property were characterized in details. Impressively, the obtained FeCo-N-GCTSs catalyst showed a positive onset potential (Eonset = 1.06 V) and half-wave potential (E1/2 = 0.88 V), revealing excellent ORR activity. Further, the FeCo-N-GCTSs assembled zinc-air battery displayed the maximum power density of 133 mW cm−2 and negligible gap change in the discharge–charge voltage plot over 288 h (ca. 864 cycles) at 5 mA cm−2, outperforming the Pt/C + RuO2 based counterpart. This work provides a facile route for construction of high-efficiency, durable and low-cost nanocatalysts for the ORR in fuel cells and rechargeable Zn-air batteries.