WS2 grafted on silicon and nano-silicon particles etched: a high-performance electrocatalyst for hydrogen evolution reaction

Abstract

Most of research has been carried out for the development of electrocatalysts for hydrogen evolution reaction (HER), which are high activity and low cost. In this study, a practical, usable, highly active, cheap, and none noble metal catalyst was developed for HER. To this end, tungsten disulfide supported on silicon (WS2/Si) and on silicon nanoparticles (WS2/nano-Si) were prepared. To increase the catalytic activity of WS2/nano-Si, chemical etching was used to prepare WS2/nano-Si etched. The synthesized electrocatalysts were characterized using Fortier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction methods. To evaluate the electrochemical attributes of WS2/Si and WS2/n-Si before and after chemical etching, electrochemical impedance spectroscopy, linear sweep, and cyclic voltammetry were used. The electrochemical measurements indicated an intense activity of the WS2/nano-Si/etched, through a high density of the current and low overpotential for HER, with a small overpotential of 0.14 V, Tafel slopes as small as 45 mV dec−1, and large cathodic currents. These results show that through etching process of silicon in HF the quantities of the active sites have been changed and increased considerably.