RESEARCHES ON CHEMICALLY MODIFIED ELECTRODES (Ⅹ)——SURFACE CHARACTERIZATION AND ION EFFECT OF PRUSSIAN BLUE MODIFIED ELECTRODE

The Prussian blue modified electrode prepared has been characterized by mcans of X-ray diffractionmethod as well as infrared spectra. The result definitely confirms that the electroactive blue film firmlyattached to Pt substrate by electrodeposition is really composed of PB, and that the specially preparedthin films on Pt possess the same crystal structure as that of the ordinary PB synthesized chemically. Avery detailed study of ion effect of supporting electrolyte strongly suggests that both reduction and oxi-dation processes of PB film are accompanied by the penetration of only cations, but not anions. Cationssuch as Na~+, as well as K~+, NH_4~+ and Cs~+ can penetrate the film, while Li~+, Ba~(2_+) and Ca~(2_+) cannot.The redox reactions of PB film has been expressed as follows: