Electrochromic properties of Prussian blue–polypyrrole composite films in dependence on parameters of synthetic procedure

Abstract

International audienceComposite materials of Prussian blue-polypyrrole (PB/PPy) on the surface of indium tin oxide (ITO)-coated glasses were obtained via one-step chemical (redox) and one-stage electrochemical procedures in mixed solution of iron (III), hexacyanoferrate (III), and pyrrole with various concentration ratios of components in nitrate supporting electrolyte. Electrochemical stability of composite films depends on the amount of Py in synthetic solution, whereas color contrast coefficient values depend on the type of synthetic procedure. PB/PPy film electrochromic response (tested by spectroelectrochemical potentiodynamic measurements) was compared with response of both pure PB and pure PPy films. It was shown that degradation of composite films occurs due to PB component instability in Prussian white form. The highest value of color contrast coefficient and great electrochemical stability were revealed for composite films obtained via redox-synthesis procedure from solution with 0.1 mM [Fe3+ + Fe(CN)(6) (3-)] and 1.0 mM D N integral (PB/PPy-Ch-1:1:10 system)

Electrochemical and electrocatalytic stability of Prussian blue/Berlin green redox transformation in Prussian blue-polypyrrole composite films

“…S1). Obtained data are in good agreement with the morphology data of PB-PPy composites synthesized by the same method from solutions of a similar composition presented in our previous work [13]. The PB crystalline structure in composite films was confirmed by SAED and XRD techniques.…”

“…Synthesis of PB-PPy composite films was performed by the one-step method based on redox reaction between an equimolar mixture of iron (III) and ferricyanide salts (an oxidizer) and pyrrole (Py) taken in excess (a reducing agent) in their mixed dilute aqueous solution by the use of a nitrate background electrolyte 0.1 M HNO 3 + 0.1 M KNO 3 (to prevent the hydrolysis of iron salts and create the excess of potassium ions in solution for PB synthesis). As it was shown in our previous work [13], optimal concentrations of reagents in reaction mixture for deposition of composites with the lowest degradation degree at potentials of PB/PW redox transfer are 0.1 mM [Fe 3+ + Fe(CN) 6 3− ] + 0.5 mM Ру (PB-PPy 1:1:5 sample) and 0.1 mM [Fe 3+ + Fe(CN) 6 3− ] + 1.0 mM Ру (PB-PPy 1:1:10 sample). These component ratios were used also in actual study.…”

“…It is well-known that stability of PB/BG redox transition is extremely low for pure PB. It was shown in our previous works [12,13] that polypyrrole matrix has a stabilizing effect on PB particles and allows to decrease the peeling of inorganic component from the electrode surface. Thus, study of electrochemical properties of PB-PPy films stability in the potential region corresponding to the redox transition PB/BG is of great interest.…”

“…In our previous works, we discussed some ways to solve the problem of low stability of PB properties especially by creating composite materials consist of PB nanoparticles and stabilizing matrix of conductive polymer polypyrrole (PPy) [12][13][14][15]. Optimal parameters of synthetic procedure [13] and reaction mixtures [12,13,15] to obtain the composite films Prussian blue-polypyrrole (PB-PPy) on the surface of optical transparent inert electrodes with the highest value of colour contrast coefficient and the lowest degradation degree were discussed.…”

Amino acid appended perylene bisimides: self-assembly, immobilization on nanocrystalline TiO2, and electrochromic properties

“…24,25,26 Amongst the most commonly used EC materials are oxides such as WO3, 27 and recently a shift towards organic EC materials based mainly on oligothiophene polymers, 28 with materials covering the full palette of colours reported. 29,30 Other materials commonly studied include viologens, 31 metallopolymers based on Ru(II) polypyridyl derivatives, 32 polyoxometalates, 16 Prussian blue, 33 and polyaniline. 34 These materials have the advantage of being fully soluble, hence they can be processed onto surfaces using conventional wet chemistry techniques, rendering them suitable for roll to roll spraying, or printing on flexible conducting substrates.…”