XPS studies on the gold oxide surface layer formation

Electrochemical impedance spectra are presented for Au|poly(o-phenylenediamine) electrodes in contact with 1 mol dm-3 perchloric acid solution. The roughness of the gold substrate and the film thickness, respectively, were systematically varied. The results obtained affirm that the dispersion of the low-frequency capacitance is connected with the inhomogeneity of the surface film, and the role of the surface roughness of the gold substrate is minor, if any, in the development of the CPE behaviour, which is in contrast to some hypotheses presented recently.