Exploring catalytic behaviors of CoS2-ReS2 heterojunction by interfacial engineering

Herein, a stable and efficient CoS₂-ReS₂ electrocatalyst is successfully constructed by using the different molar ratios of CoS₂ on ReS₂. The size and morphology of the catalysts are significantly changed after the CoS₂ is grown on ReS₂, providing regulation of the catalytic activity of ReS₂. Particularly, the optimized CoS₂-ReS₂ shows superior electrocatalytic properties with a low voltage of 1.48 V at 20 mA cm⁻² for overall water splitting in 1.0 M KOH, which is smaller than the noble metal-based catalysts (1.77 V at 20 mA cm⁻²). The XPS, XAS, and theoretical data confirm that the interfacial regulation of ReS₂ by CoS₂ can provide rich edge catalytic sites, which greatly optimizes the catalytic kinetics and drop the energy barrier for oxygen/hydrogen evolution reactions. Our results demonstrated that interfacial engineering is an efficient route for fabricating high-performance water splitting electrocatalysts.