An efficient Co3S4/CoP hybrid catalyst for electrocatalytic hydrogen evolution

Abstract

The development of efficient, universal and inexpensive electrocatalysts for hydrogen evolution reaction (HER) is central to the area of sustainable energy conversion. Considering the Co-based sulfides/phosphides have the same catalytic mechanism with the hydrogenases occurring in nature. Here, a new catalyst based on Co3S4/CoP hybrid that is comprised entirely cheap and earthabundant elements, was first synthesized via a two-step method, the Co(CO3)0.5(OH)0.11H2O precursor was prepared by a hydrothermal method, followed by phosphidation and sulphidation under Ar atmosphere simultaneously. The resulting Co3S4/CoP hybrid material possessed porous core-shell structure with a homogeneous element distribution and large electroactive surface area (21.04 mF cm-2). More importantly, the nanostructured Co3S4/CoP electrode exhibits excellent HER properties in acid medium with a low onset overpotential of 34 mV, a small Tafel slope of 45 mV dec-1, as well as a large exchange current density of 150 μA cm-2. These results obtained in this study indicate that the Co3S4/CoP hybrid nanorod is promising replacement to the Pt-based catalysts for H2 production. Moreover, the synthetic method presented in this work can provide an efficient way to synthesis other nanocomposites.