In-situ external reflection FTIR spectroelectrochemical and XPS investigations of cobalt-cyanometallates as inorganic polymeric materials on a platinum electrode.
Cobalt-cyanometallate films electrochemically deposited on a platinum electrode were studied by cyclic voltammetry (CV), in-situ FTIR spectroelectrochemistry (FTIRs) and potential resolved XPS measurements. The experimental results reveal that the CoHCF film on Pt electrode exists in two forms. The major form of the inner layer of the film is (M(+))(2)Co(II)Fe(II)(CN)(6) where M(+)denotes a cationic counter ion, in which both the Fe(2+)and Co(2+)centers can be oxidized to Fe(3+)and Co(3+)in the potential range of 0-1.0 V vs. Ag/AgCl in NaCl solution. The major form of the outer layer is Co(II)(2)Fe(II)(CN)(6), in which electrochemical reactions in this potential range are limited by kinetic sluggishness. The FTIR and XPS spectra indicated that the Co centers change from high-spin state to low-spin state accompanying the Co(2+)/Co(3+)oxidation reaction. In addition, the cations' effect on electrochemical reactions of CoHCF is also discussed.
Electrochemical studies on the interfacial behaviors for the eco-friendly magnetic nanoparticles based on γ-Fe2O3
Abstract Biocompatible gallic acid (GA) was conjugated on the shell of γ-Fe 2 O 3 encapsulated with bio-inspired polydopamine (PDA) to form novel environment friendly magnetic nanoparticles, γ-Fe 2 O 3 /PDA/GA. To elucidate the effect of the grafted GA, γ-Fe 2 O 3 /PDA and γ-Fe 2 O 3 /PDA/GA were used to modified electrodes. Cyclic voltammetry (CV), square wave anodic stripping voltammetry (SWASV) and electrochemical impedance spectroscopy (EIS) were adopted to comparatively study their interfacial properties, their chelating abilities and their electrochemical responses to Cu 2+ and Pb 2+ .
Electrochromism of Polyaniline: An In Situ FTIR Study
Electrochromic thin films of polyaniline were prepared by electropolymerization of aniline from an acidic aqueous solution on platinum and conducting glass surfaces. An in situ FTIR spectroelectrochemical technique was used to investigate structural changes of the film during oxidation and reduction. Coloring (oxidation) and bleaching (reduction) of the film were shown to be associated with the deprotonation and protonation of the film. It was detected that the N‒H stretching band around 2970 cm−1 decreased as the film was gradually oxidized.