Synthesis and Characterization of Copper Hexacyanoferrate Nanoparticles for Building Up Long-Term Stability Electrochromic Electrodes

Abstract

Nanoparticles of a Prussian blue (PB) analogue, copper hexacyanoferrate, were synthesized by using ultrasonic radiation and characterized by spectroscopic and electrochemical techniques. The nanoparticles (ca. 10 nm diameter) were immobilized onto transparent indium tin oxide electrodes by electrostatic layer-by-layer deposition. These modified electrodes showed interesting electrochromic properties, changing the coloration during the redox process from brown to orange when oxidized. The nanostructured electrode presented high stability, in contrast to that observed for PB nanoparticles; this fact must be related to the maintenance of the electrostatic assembly because the oxidized compound, CuII/FeIII(CN)6, still possesses a negative excess of charge due to the high number of cyanide groups that link the nanoparticles with the polycation, assuring the integrity of the whole electrostatic assembled film.

Biosensors based on gold nanostructures

“…This method can be extended for both nanoparticles and charged biomolecules immobilization. Assemblies between nanoparticles and charged polymers were also reported in literature, for SiO 2 nanoparticles and poly(diallyldimethylammonium chloride) (PDDA), 106 Prussian blue nanoparticles 107 and analogues 108,109 and nickel hydroxide nanoparticles. 110,111 Multilayer films of GOx/AuNPs on Au electrode surface using cysteamine as covalent attachment crosslinker, prepared by LbL technique, was performed by Yang et al 112 Bioelectrocatalytic response was directly correlated to the number of deposited bilayers, due to the amount of active enzyme immobilized on the Au surface.…”

Nanochromics: old materials, new structures and architectures for high performance devices

“…Recently, Baioni et al 40 reported the synthesis of copper hexacyanoferrate nanoparticles, a Prussian blue derivative, by employing ultrasound radiation. Prussian blue analogues are of great interest, because it is well known that PB lack electroactivity in Na + media.…”

Nanostructured thin films obtained by electrodeposition over a colloidal crystal template: applications in electrochemical devices

“…Besides, it turns more significant according to the decrease in the concave or convex surface size. Aurlier publication using spherical nanoparticles showed that the electrochemical response obtained when nanoparticles replace bulk compounds as mediator in biosensors 46,47 or in electrochemical devices 48 is improved. As stated before, the improvement is related not only to the exposition of more active sites available due to the larger surface area but also to the high chemical potential presented by these atoms.…”