Abstract: Probe beam deflection(PBD) technique together with electrochemical techniques such as cyclic voltammetry was used to study the ion exchange in prussian blue(PB) film and its analogue indium hexacyanoferrate(InHCF) chemically modified electrodes.The ion exchange mechanism of PBwas verified as following: where on reduction in contact with an acidic KCl electrolyte,H⁺enter PBfilm before K⁺.Both the cations and anions participate concurrently in the redox process of InHCF,meanwhile K⁺ion plays a majr role in the whole charge transfer process of this film with increasing radii of anions.

Key words: Probe beam deflection, Prussian blue film, Indium hexacyanoferrate film, Ion exchange mechanism