A highly active hydrogen evolution electrocatalyst based on a cobalt–nickel sulfide composite electrode

Abstract

A novel Co₉S₈–Ni_xS_y/Ni foam composite material was synthesized through the thermal decomposition of a cobalt–thiourea molecular precursor onto a 3D metallic support. The obtained electrode exhibited good activity toward the hydrogen evolution reaction in an alkaline medium, requiring a small overpotential of 163 mV at a current density of 10 mA cm⁻², which is one of the lowest ever reported among transition metal sulfide materials.