Enhanced oxygen evolution based on vertically and well aligned silicon nanowires

Abstract

Vertically and well aligned silicon nanowires (SiNWs) were fabricated, characterized and utilized to provide a high surface area and a high electrocatalytic activity for co-catalyst loading with a guiding 1-D charge transfer along the fabricated SiNWs. The impact of SiNWs structural features on the electrocatalytic properties of the fabricated samples and the cyclic voltammetry (CV) performance of Si and SiNWs electrodes were explored in 1.0 M KOH and 0.1 M H2SO4. The evaluation of oxygen evolution rection and the hydrogen evolution reaction were carried out using potentiostat/galvanostat with a three-electrode conventional system using a platinum wire as a counter electrode, Ag|AgCl|KClsat as a reference electrode, and a substrate having SiNWs nanostructure on its surface (catalysts) as a working electrode. For further investigations, we studied the oxygen evolution reaction (OER) performance of SiNWs and compared with that of Si electrodes based upon the electrochemical impedance spectroscopy (EIS). SiNWs achieved more efficient charge transport, owing to the direct conduction pathway and exhibited considerable stability as well as maximum amount of oxygen bubbles at a drive current of 708.6 μA/cm2 under a potential of 1.5 V in alkaline media.