In situ electrochemical preparation and characterization of PEDOT–Prussian blue composite materials

Inorganic–organic composite electrode materials consisting of Prussian blue (PB) and poly[3,4-ethylenedioxythiophene] (PEDOT) were developed. The composite inorganic–organic coatings have been prepared by electrochemical methods in various compositions onto Pt electrode substrate. The composite coatings were prepared by both potentiodynamic and galvanostatic methods. The electrochemical properties of these composites materials were investigated by cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The electrochemical behavior of the electrode materials is based mainly on the redox reaction of the inorganic component. The thickness of the composite coatings was estimated from EQCM data. The potentiodynamic method proved to be more efficient for the incorporation of soluble PB within the PEDOT matrix, while the galvanostatic method showed an enhanced efficiency in the incorporation of insoluble PB. The preparation of both insoluble and soluble PB forms within the PEDOT coating and the investigation of their electrochemical properties and analytical applications in the amperometric determination of hydrogen peroxide are also presented. The composite coatings prepared through galvanostatic methods showed larger sensitivities for hydrogen peroxide detection in comparison with those prepared by potentiodynamic method.