Effect of sodium dodecyl sulphate on Cu electrodeposition: interaction with hydrophobic substrate and Cu ions

Abstract

In this study, the effect of sodium dodecyl sulphate (SDS) on Cu electrodeposition was evaluated using cyclic voltammetry. With the weak adsorption of SDS on Cu and Au surfaces, SDS slightly altered the cyclic voltammogram for Cu electrodeposition on these surfaces. However, the cyclic voltammogram on glassy carbon (GC) and pyrolytic graphite significantly changed with the addition of SDS, indicating that the hydrophobic interactions are critical for SDS adsorption. SDS adsorbed on the GC surface exhibiting an increase in current response, an indication of the enhancement of Cu nucleation, confirmed by the increase in the nuclei density on the GC surface. Moreover, the addition of SDS splits the voltammetric wave on GC, indicating that SDS might stabilise Cu+ intermediates that are probably associated with SDS micelles. In addition, the micellar association might lower the diffusion coefficient of Cu2+ leading to a depression in the reduction peaks in the cyclic voltammograms.