WS2 Grafted on Silica and Nano-Silica Particles Etched, A High-Performance Electrocatalyst for Hydrogen Evolution Reaction,
Ali A. Ensafi, F. Ghadirian, M. Jafari-Asl, B. Rezaei,
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.