Transition metal based ternary hierarchical metal sulphide microspheres as electrocatalyst for splitting of water into hydrogen and oxygen fuel

The production of hydrogen as a clean energy source by a facile method are major concern and promising research area now a days. The electrolysis of water to generate hydrogen and oxygen as a fuel are challenging renewable energy technology. To develop a highly efficient low-cost non-noble metal-based catalyst for hydrogen evolution reaction (HER) is essential and urgent need. Thus, the present work describes a facile synthetic approach to develop suitable cost effective electrocatalyst for water splitting application. It deals one-pot synthesis of low-cost transition metal based ternary metal sulphide (BMS) CuCo2S4, CuMn2S4, CuNi2S4, and CuZn2S4 microspheres as electrocatalyst to generate hydrogen from water. The physical characterization of synthesized electrocatalyst were performed by powder x-ray diffractometer (PXRD) and Raman spectroscopy. The morphological characterization of synthesized electrocatalyst were done by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) however the elemental mapping analysis was done by energy-dispersive X-ray spectroscopy (EDX). The electrochemical measurements were performed in 0.5 M H2SO4 acidic medium on 3-electrode polymer electrolyser membrane water (PEMW) system. The lowest onset and overpotential values have been observed as 61 and 79 mV, respectively in the case of CuCo2S4 micro-sphere. However, the Tafel slope values of CuCo2S4, CuMn2S4, CuNi2S4, and CuZn2S4 electrocatalysts were calculated 121, 115, 102 and 41 mV respectively. On the basis of obtained electrochemical characterization results, CuCo2S4 has been revealed better electrocatalyst under acidic media. This study opens a new direction to consider low-cost transition metal based ternary microspheres as electrocatalyst to produce hydrogen during water electrolysis.