Ultrafine NiCoP-decorated N,S,P-codoped hierarchical porous carbon nanosheets as an efficient bifunctional electrocatalyst for oxygen reduction and oxygen evolution

Abstract

It is a great challenge to explore novel bifunctional electrocatalysts with low cost, high activity and improved stability for metal–air batteries. In this work, ultrafine NiCoP nanoparticles decorated on N,S,P-codoped hierarchical porous carbon nanosheets (NiCoP/NSP-HPCNS) were fabricated via a simple yet effective pyrolysis strategy. Herein, thiourea and phytic acid (PA) served as S and P sources, cobalt acetate (CA) and nickel phthalocyanine (NiPc) as the metal, C and N precursors. The NiCoP/NSP-HPCNS displayed extraordinary enhancement in oxygen reduction reaction (ORR), with a half-wave potential of 0.84 V (vs. RHE) and enhanced limiting current density of 6 mA cm⁻² in 0.1 M KOH, outperforming commercial Pt/C (0.84 V vs. RHE and 5.1 mA cm⁻²). Furthermore, the catalyst exhibited outstanding catalytic performance for oxygen evolution reaction (OER), with a low overpotential of 299 mV at the current density of 10 mA cm⁻² in 1 M KOH. This work opens up a new avenue to prepare highly effective, low cost and bifunctional electrocatalysts for sustainable energy applications.