Electrochromic Behavior of Prussian Yellow

Abstract

Prussian Blue films were studied by in situ electrogravimetric and spectroelectrochemical methods during the electrochemical oxidation to the Prussian Yellow form. Spectroelectrochemical studies detected important absorbance changes during electrochemical experiments at 430 nm and 690 nm corresponding to the appearance of the yellow form and to the disappearance of the characteristic blue color. These changes of absorbance were well related with the voltammetric peaks. This redox process has also been studied by in situ electrochemical impedance spectroscopy, mass impedance and color impedance at 690 nm. It has been found that crossed impedance functions obtained from the original ones provide interesting information on the participation of both, cations and anions during electrochemical processes.