VS2: an efficient catalyst for an electrochemical hydrogen evolution reaction in an acidic medium

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 47; no. 39; pp. 13792 - 13799
• Main Authors: Das, Jiban K, Samantara, Aneeya K, Nayak, Arpan K, Pradhan, Debabrata, Behera, J N
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 2018
• Subjects: Acidic oxides; Catalysis; Catalysts; Charge transfer; Crystal lattices; Electrocatalysts; Electrodes; Electrolysis; Energy conversion; Graphene; Hydrogen evolution reactions; Light; Stability tests; Sulfuric acid; Thermogravimetric analysis
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c8dt02547a

In view of preparing efficient electrocatalysts for energy conversion applications, we have developed an eco-friendly, cost effective, single step method for the scalable synthesis of VS2 and its reduced graphene oxide composite VS4/rGO. Furthermore, the electrocatalytic performances of the catalysts have been studied toward the hydrogen evolution reaction in an acid medium (0.1 M H2SO4). Presumably, the large exposed electrochemical active surface area (27.7 cm2) and hexagonal crystal lattice of VS2 result in its dominating catalytic performance over that of the linear VS4/rGO composite. Also, a VS2 modified electrode was demonstrated to have better stability (with a negligible change in the overpotential even after 10 h and 43 h of continuous electrolysis) with a notably low Tafel slope (36 mV dec−1, close to that of commercial Pt/C) and onset potential (15 mV vs. RHE) with robust durability for long term application. A preliminary study on the photoelectrochemical activities of VS2 showed a significant decrease in the charge transfer resistance upon illumination of light on the electrode surface.