Nano-Engineered Vanadium Doped NiS Catalyst for Efficient Electrochemical Water Splitting

In this work, we demonstrate a single step hydrothermally grown nanorod shaped pristine and Vanadium (V) doped NiS on highly porous nickel foam substrate, i.e., NiS@NF and V-NiS@NF. A detailed electrochemical analysis, in terms of hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and Tafel slope, suggests that V doping enhances the electrocatalytic activity of NiS@NF for water splitting. V-NiS@NF delivered 172 mV HER and 310 mV OER overpotentials at current densities of 10 mA/cm2 and 50 mA/cm2, respectively. The Tafel slope values for HER and OER of V-NiS@NF are 45 mV/dec and 25 mV/dec, respectively. The better electrocatalytic performance of V-NiS@NF as compared to the NiS@NF was attributed to the matching of the atomic radius and deformation of the electronic structure of the pristine NiS@NF resulting in higher active sites. Due to the bifunctional nature with moderate HER/OER overpotentials and ease of synthesis, the present electrocatalyst V-NiS@NF can be used to develop an efficient electrolyzer for green hydrogen generation through water splitting.