Nucleation of metals on conductive polymers: Electrodeposition of silver on thin polypyrrole films

The electrodeposition of silver was examined under conditions that excluded a possibility of electroless formation of polypyrrole and silver crystallites. The polymer layers were appropriately prepared; after finishing the polymerization and before the silver reduction they were oxidized. A comparison of the theoretical chronoamperograms with the experimental data, appropriately corrected for the induction time, revealed that the progressive nucleation took place for all examined polymer films and deposition potentials. For lower overpotentials the Ag nuclei were mainly formed under the polymer layer and in its pores. An explanation was given for why the Ag crystallites cannot be completely oxidized from the polypyrrole films.