Nano bowl-like cobalt–cobalt molybdenum carbide coated by N,P co-doped carbon as an advanced bifunctional oxygen electrocatalyst for rechargeable Zn–air batteries

Abstract

Nano bowl-like Co–Co₆Mo₆C₂ coated by N,P co-doped carbon (Co–Co₆Mo₆C₂@NPC) is reported as an electrocatalyst for Zn–air batteries. Co–Co₆Mo₆C₂@NPC only needs an overpotential of 210 mV at 10 mA cm⁻² for the OER, and the half-wave potential for the ORR is 0.81 V. In addition, the Co–Co₆Mo₆C₂@NPC based battery shows a large open-circuit voltage of 1.335 V and a maximum power density of 160.5 mW cm⁻², as well as good stability. The improved catalytic performance can be ascribed to the co-existence of Co₆Mo₆C₂ and Co species to improve the intrinsic catalytic activity, and the bowl-like nanostructure to facilitate the mass transfer.