Electrochemical Activation of Silicon: Enhancing Hydrogen Production from FeNi Electrocatalysts

Abstract

A two-sided electrode composed of FexNi100–xOy and Si was implemented to produce hydrogen. The hydrogen evolution reaction is facilitated by the FexNi100–xOy electrocatalyst. The high pH of the alkaline electrolyte and the reducing potential of the electrode result in the activation of the Si side, allowing spontaneous production of H2. Results demonstrate that the FexNi100–xOy composition and the electrolyte composition influence the performance of the FexNi100–xOy/Si system. The activation and subsequent production of H2 by the Si was demonstrated to be favored in 0.1 M KOH and NaOH electrolytes over LiOH, and this result was consistent when the electrochemical cell was operated under applied voltage and at open circuit voltage. At the same time, results showed that the Fe80Ni20/Si composition maintained a current of −10 mA at a lower potential (∼50 mV) compared to the Fe20Ni80/Si composition. Overall, the results of this study demonstrate that the two-sided FexNi100–xOy/Si electrode can be used to boost the production of hydrogen, leading to a maximum of 140% H2 efficiency, which includes both Faradaic H2 production and non-Faradaic H2 evolution through Si corrosion.