Electrochemical and Spectroscopic Studies of Metal Hexacyanometalate Films: I . Cupric Hexacyanoferrate

Abstract

A method for the electrodeposition of thin films of cupric hexacyanoferrate on glassy carbon and tin oxide electrodes has been devised. At low scan rates, in , these films exhibit nearly ideal cyclic voltammetric current‐potential waves with a peak potential of +0.69V vs. SCE on glassy carbon. Similar to the Prussian blue films described by Neff (1, 2), Itaya (3), and others (4), potassium ion is transported into the film during reduction. XPS and visible spectroscopy indicate that the redox involves the ferric and ferrous states of the hexacyanoferrate and not . The electrochemical properties as a function of potassium ion concentration and film thickness have been determined primarily from cyclic voltammetric studies, and evidence for electronic conduction through the film has been observed. Optical properties of the films were determined using deposited on tin oxide substrates. Supporting description of the electrochemical properties of the film has been obtained by a‐c impedance measurements. The film behavior is consistent with a model previously reported for Prussian blue films.