Snowflake-like Metastable Wurtzite CuGaS/MoS Composite with Superior Electrochemical HER Activity.

In the present work, we report the synthesis of wurtzite CuGaS and its composite with MoS and explored their efficacy toward two important applications, viz. electrocatalytic hydrogen evolution reaction (HER) and adsorption of Rhodamine B dye. The CuGaS 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 CuGaS and CuGaS/MoS composites toward HER was investigated, wherein the CuGaS/MoS composite exhibited superior activity when compared to the pristine sample with a small Tafel slope of 56.2 mV dec and an overpotential value of -464 mV at the current density of 10 mA cm. On the other hand, the synthesized CuGaS 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.