Comparative Study for the Electrodeposited Cadmium Chalcogenide by Potentiostatic and Potentiodynamic Methods for Electrochemical Reduction of CO2

Abstract

Electrochemically synthesized cadmium sulfide (CdS) on cupper-modified substrate from an acidic solution containing Cd2+ and S2O32- ions at 20oC has been produced with potentiostatic and potentiodynamic methods utilizing a three-electrode system. The prepared films have been characterized utilizing X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). X-ray diffraction analyses demonstrate that, under our optimized conditions, the CdS thin films deposited using both methods exhibit a pure and hexagonal structure. The electrodeposited CdS was found to behave as a p-type semiconductor, which was examined and demonstrated via the Mott-Schottky measurement. Depending upon the obtained data in this work, it was discovered that the electrodeposition techniques affect the morphology of the electrodeposited material (confirmed by SEM), carrier concentrations, thickness δSC of the space-charge layer, the energy gap (Eg), as well as the sensitivity towards CO2 electro-reduction.