Modification of electrochemically roughened Au(111) by underpotentially deposited silver and its effect on the subsequent electrodeposition of polypyrrole

In this study, electrochemically roughened Au(111) is modified with underpotential deposition (UPD) silver for the first time. The formation of self-assembled monolayers of pyrrole monomers and subsequently further autopolymerization are found on the UPD-Ag-modified gold surfaces. The presence of UPD Ag improves the stability of polypyrrole (PPy) monolayers against desorption in a sonicating bath at elevated temperature. Furthermore, the nucleation and growth mechanism for PPy electropolymerized on UPD-Ag-modified Au is distinguishable from that on unmodified Au. The corresponding conductivity and the Raman intensity of PPy electropolymerized on UPD-Ag-modified Au increase by about 2-fold and 4-fold, respectively.