Adsorption of aniline on a polycrystalline gold electrode: Determination of thermodynamic parameters and electroreflectance investigation

摘要: Abstract Combined capacity and electroreflectance measurements have been employed to investigate the adsorption of aniline on a polycrystalline gold electrode in neutral aqueous solution. Thermodynamical analysis capacity-potential curves allowed calculation different parameters. The Frumkin isotherm was obeyed, indicating repulsive interaction adsorbed layer. standard Gibbs energy found be fairly large (~ 47 kJ mol −1 ) showing presence chemical between adsorbate electrode. This confirmed by spectra, whose lineshape electric field-dependent drastically perturbed when applied potential close that oxidation polymerization aniline. At this latter potential, surface concentration species about 2.6 × 10 −10 cm −2 ; value is compatible with monolayer flat oriented molecules. In negative charge region, lies electrode, but π-electrons weaker than positive region.