Superstructured Carbon with Enhanced Kinetics for Zinc‐Air Battery and Self‐Powered Overall Water Splitting

Abstract

AbstractThe present study proposes a novel engineering concept for the customization of functionality and construction of superstructure to fabricate 2D monolayered N‐doped carbon superstructure electrocatalysts decorated with Co single atoms or Co2P nanoparticles derived from 2D bimetallic ZnCo‐ZIF superstructure precursors. The hierarchically porous carbon superstructure maximizes the exposure of accessible active sites, enhances electron/mass transport efficiency, and accelerates reaction kinetics simultaneously. Consequently, the Co single atoms embedded N‐doped carbon superstructure (Co‐NCS) exhibits remarkable catalytic activity toward oxygen reduction reaction, achieving a half‐wave potential of 0.886 V versus RHE. Additionally, the Co2P nanoparticles embedded N‐doped carbon superstructure (Co2P‐NCS) demonstrates high activity for both oxygen evolution reaction and hydrogen evolution reaction, delivering low overpotentials of 292 mV at 10 mA cm−2 and 193 mV at 10 mA cm−2 respectively. Impressively, when employed in an assembled rechargeable Zn‐air battery, the as‐prepared 2D carbon superstructure electrocatalysts exhibit exceptional performance with a peak power density of 219 mW cm−2 and a minimal charge/discharge voltage gap of only 1.16 V at 100 mA cm−2. Moreover, the cell voltage required to drive an overall water‐splitting electrolyzer at a current density of 10 mA cm−2 is merely 1.69 V using these catalysts as electrodes.