Snowflake-like Metastable Wurtzite CuGaS2/MoS2Composite with Superior Electrochemical HER Activity

Abstract

In the present work, we report the synthesis of wurtzite CuGaS2 and its composite with MoS2 and explored their efficacy toward two important applications, viz. electrocatalytic hydrogen evolution reaction (HER) and adsorption of Rhodamine B dye. The CuGaS2 was synthesized via a low-temperature ethylenediamine-mediated solvothermal method. The obtained products were characterized by various techniques such as X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy to ascertain the phase formation, surface morphology, and elemental oxidation states. The electrocatalytic activity of the wurtzite CuGaS2 and CuGaS2/MoS2 composites toward HER was investigated, wherein the CuGaS2/MoS2 composite exhibited superior activity when compared to the pristine sample with a small Tafel slope of 56.2 mV dec-1 and an overpotential value of -464 mV at the current density of 10 mA cm-2. On the other hand, the synthesized CuGaS2 also showed an impressive adsorption behavior toward Rhodamine B dye with 99% adsorption in 60 min, which is relatively better than that observed with the composite material.