Ultra-efficient, low-cost and carbon-supported transition metal sulphide as a platinum free electrocatalyst towards hydrogen evolution reaction at alkaline medium

Hydrogen (H₂) is the future energy carrier and it is quite challenging to produce at a large-scale on economic basis. The water splitting technique has achieved a good place in H₂ production. To generate efficient electrocatalysts for the Hydrogen evolution reaction (HER), low-cost synthetic designs are necessary. In our study, a one-step co-precipitation reduction process was used to synthesize NiWS electrocatalyst. The crystalline structure, phase purity, elemental composition and the surface morphology of the as-prepared samples have been examined by different characterization techniques. These techniques have proved that the elemental presence and formation of NiWS with high crystalline nature (rhombohedral). Furthermore, the performance of the electrocatalyst towards HER has been evaluated through electrochemical methods. On analysis, NiWS/CNT showed an excellent electrochemical activity of 175 mV, and pure NiWS showed 201 mV at 10 mA/cm² in an alkaline electrolyte. These over-potential values are lower than HER in acid and neutral electrolytes. Further, the as-prepared NiWS/CNT proved to be a highly stable and efficient platinum-free electrocatalyst for HER.