Characteristics of Cl- and Au-containing nanocomplex and its effect on the following electrodeposition of polypyrrole

In this study, polypyrrole (PPy) films were electrochemically deposited on gold substrates roughened by a triangular-wave oxidation-reduction cycle (ORC) with different anodic and cathodic vertexes in an aqueous solution containing 0.1 N NaCl. In ORC treatment, the Cl- and Au-containing nanocomplex was formed on the surface of gold. The results indicate that the crystalline orientation and diameter of Au are significantly different before and after ORC treatment. Also the redox behavior in ORC, surface morphology formed and depth profile of Cl in the nanocomplex are influenced by the anodic and cathodic vertexes used in roughening Au. The roughened Au demonstrates an electrocatalytic activity for pyrrole polymerization. Correspondingly, the characteristics of PPy films electrodeposited on these roughened Au substrates are notable. They include the surface-enhanced Raman scattering (SERS) effect shown, a higher conductivity obtained and an increase in oxidation level demonstrated.