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.