The Open Physical Chemistry Journal

2007, 1 : 33-38
Published online 2007 December 18. DOI: 10.2174/1874067700701010033
Publisher ID: TOPCJ-1-33

An Optical Impedance Investigation of a Gold Electrodeposition System

Benedetto Bozzini , Claudio Mele and Lucia D'Urzo
Dipartimento di Ingegneria dell'Innovazione, Università del Salento (formerly: Università di Lecce), via Monteroni, I-73100 Lecce, Italy.

ABSTRACT

In this paper in situ visible electroreflectance measurements have been carried out in order to extract new electrochemical information from the dependence of ΔR/R on the frequency of potential modulation. The behaviour of some typical components of a Au electrodeposition bath has been investigated: a metal salt (KAu(CN)2), a supporting electrolyte (NaClO4), a metal cation complexing agent (KCN). The voltammetric behaviour of the relevant systems has been investigated by means of Cyclic Voltammetry (CV) and Electrochemical Impedance Spectrometry (EIS). The optical and current density dynamics have been compared applying a potential square-wave modulation with frequencies in the range 1÷300 Hz and have been found to exhibit clearly different time-constants. Sensitivity to the electrolyte chemistry and radiation- wavelength have been proved for optical impedance.

Keywords:

Electrodeposition, electroreflectance, gold.