Cationic-exchange approach for conversion of two dimensional CdS to two dimensional Ag2S nanowires with an intermediate core–shell nanostructure towards supercapacitor application

Abstract

An easy ion-exchange route has been utilized to replace the toxic cadmium ions with silver in cadmium sulfide nanowires to obtain silver sulfide nanowires as the end product, since direct deposition of such novel morphology of silver sulfide has been a great challenge. This work is based on the concept of negative free energy of formation. In course of this process, CdS, CdS/Ag₂S core–shell heterostructures and Ag₂S nanowires as the end product were obtained, and has been employed as supercapacitor electrodes where completely converted Ag₂S nanowires showed a highest capacitance of 268.4 F g⁻¹ at 1.5 mA cm⁻² current density in 1.5 M NaOH electrolyte. This simple approach promises a new electrode engineering technique just by controlling the reaction stage in the cationic source where a less toxic end product can be obtained with enhanced performance.