Influence of the Fe(CN)₆³⁻/Fe(CN)₆⁴⁻ Redox Reaction on the Changes in Surface Energy of a Gold Electrode in Perchlorate Solution with Iodide Ions

Abstract

Two novel techniques of piezoelectric detection and laser-beam deflection were employed to examine the influence of the Fe(CN)₆³⁻/Fe(CN)₆⁴⁻ redox reaction on the changes in surface energy of a gold electrode in perchlorate solutions with and without iodide ions. In the absence of iodide ions, both piezoelectric signal curve and electrocapillary curve suggested the specific adsorption of Fe(CN)₆³⁻, Fe(CN)₆⁴⁻ or its decomposed product such as Prussian blue on the gold electrode. On the other hand, in the presence of iodide ions, it was found that the strong specific adsorption of iodide ions on the gold electrode inhibits the adsorption of the redox couple or Prussian blue.