Kinetics of copper electrodeposition onto Polypyrrole films previously synthesised onto iron in oxalic aqueous solution. Application to electrocatalysis

Copper electrodeposition onto previously synthesised Polypyrrole (PPy) onto iron in oxalic medium has been investigated using polarization and electrochemical impedance spectroscopy. This investigation was done at potential range where hydrogen evolution does not occur. The kinetics of this reaction was found to be under diffusion control and the diffusion coefficient of reactive species was found to be 6.4 +/- 0.1 x 10(-6) cm(2) s(-1). The electrochemical impedance spectroscopy was used to estimate the roughness variation of the electrode surface during copper electrodeposition. Scanning Electron Microscopy observation of Fe/PPy/Cu films provide strong evidence of the close relationship between deposit morphology and electrocatalytic activity. (c) 2006 Elsevier B.V. All rights reserved.