J. Phys. Chem. 1981, 85, 1225-1231
1225
Electrochromism in the Mixed-Valence Hexacyanides. 1. Voltammetric and Spectral Studies of the Oxidation and Reduction of Thin Films of Prussian Blue D. Ellis, M. Eckhoff,?and V. D. Neff Department of Chemistry, Kent State University, Kent, Ohio 44242 (Received: November 4, 1980; In Final Form: January 8, 1981)
A thin film of Prussian blue (KFeFe(CN6)),on a platinum or gold substrate, is reduced to Everitt’s salt (K2FeFe(CN6))at 0.195 V (vs. SCE) or is oxidized to Berlin green (K1!3Fe(Fe”’(CN)6)2/3(Fe11(CN)6)l/3) at 0.870 V in 1 N KCl or K2S04solutions. It is shown that potassium ion migrates into or out of the film during the electrolysis. Both reactions are reversible at sweep rates of
