Skutterudite-Type Ternary Co_1–<i>x</i>Ni_<i>x</i>P₃ Nanoneedle Array Electrocatalysts for Enhanced Hydrogen and Oxygen Evolution

Abstract

Developing earth-abundant and low-cost electrocatalysts for water splitting is important for the conversion systems of renewable and clean energy. Herein, under the guidance of theoretical calculations, a new type of skutterudite-type ternary cobalt nickel phosphide (Co1–xNixP3) nanoneedle arrays (NAs) is fabricated on carbon cloth for the splitting of water. The electronic structure was tuned by doping an appropriate amount of Ni, and the resultant Co0.93Ni0.07P3 displayed good catalytic activity toward hydrogen evolution reaction (HER) with an overpotential (η10) of 87 mV versus reversible hydrogen electrode (RHE) when the current density reaches −10 mA cm–2 and the Tafel slope of the catalyst is 60.7 mV dec–1 in alkaline electrolyte. In addition, the Co0.93Ni0.07P3 also exhibited an OER activity (η20 of 221 mV vs RHE and the Tafel slope of 83.7 mV dec–1). These skutterudite-based Co1–xNixP3 electrocatalysts show promising potential in the applications of overall water splitting in an alkaline environment.