Derivative voltabsommetric scans in near-UV/visible-NIR electromagnetic range together with nano-electrogravimetric measurements during the stabilization process of Prussian Blue in NH4Cl aqueous solution yields information about the localization of the into the crystalline structure of this material. It is proposed that the ammonium ion is placed into the vacancies of the framework that affect to the motional resistance. The simultaneous measure of current, mass, motional resistance, and near-UV-vi-N IR spectra allows to explain the differences observed between the Prussian Blue films placed in a solution of NH4Cl salt regarding the behaviour showed in KCl aqueous solution.
The role of the ammonium cation on the reversible electrochemistry of Prussian Blue thin films was analyzed through in situ combination of three different impedance techniques. Electrochemical impedance spectroscopy provides information on the electron transfer. Mass impedance spectroscopy allows the exchange of free water, ammonium and proton ions to be elucidated. Color impedance spectroscopy provides the kinetics of electrochromic changes of Prussian Blue structure (main backbone structure, ferrocyanide vacancies and trapped structures). The simultaneous measurement of the three impedances gives detailed information on the mechanism of the whole process, specifically one faster and two slower, which have been identified during the electrochemical reactions of Prussian Blue films in NH 4 Cl acidic solutions.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.