One-step synthesis of CoS₂/g-C₃N₄ composite as electrocatalyst for hydrogen evolution reaction

Abstract

In this paper we present the one-step calcination route at various temperatures (T= 450, 500, and 550°C) for 4 hours with precursors cobalt (II) acetate tetrahydrate and thiourea to synthesize the CoS₂/g-C₃N₄, nanocomposite (denoted as 450CSCN, 500CSCN and 550CSCN) as electrocatalysts for hydrogen evolution reaction (HER) under acidic solution. The results show that the temperature significantly affects the morphology of the composites. Among the composites, 500CSCN exhibited a low overpotential of 222mV at a current density of 10mA/cm² and a Tafel slope of 80mV/dec, much better than those of 450CSCN (468mV, 98mV/dec) and 550CSCN (390mV, 85mV/dec). Moreover, the presence of g-C₃N₄, in the composite causes highly active sites to facilitate the HER. Our approach for designing CoS₂/g-C₃N₄, composites may provide a feasible way to produce electrocatalysts with high performance for HER.