Nickel-cobalt bimetal phosphide integrated in nitrogen-doped carbon being a novel chainmail electrocatalyst for oxygen evolution

Abstract

The valid and stable non-precious electrocatalysts are particularly meaningful for facilitating the production of hydrogen by utilizing overall water-splitting technology. In addition, the transition metal phosphides (TMPs) nanomaterials with individual electrical and catalytic properties, show immense application prospects in the fields of water electrolysis for hydrogen production. Herein, we construct a novel electrocatalyst (Ni2P–CoP@NC) with high stability for oxygen evolution reaction (OER), consisting of cobalt-nickel bimetallic phosphide (Ni2P–CoP) wrapped by nitrogen-doped carbon (NC) layers. The prepared Ni2P–CoP@NC demonstrated an excellent OER performance, with a low overpotential of 267 mV at a current density of 10 mA cm−2 and a Tafel slope of 95 mV dec−1. And the Ni2P–CoP@NC catalyst, with no distinct performance degradation over 40 h under the current density of 10 mA cm−2, show a significantly improved stability compared to the bare Ni2P–CoP catalyst, owing to the protective function of the nitrogen-doped carbon shell. This work provides a novel approach for the construction of high-performance as well as robust bimetallic phosphide chain-mail electrocatalysts for OER.