Electrochemical behavior of tungsten-containing nanocomposite with siloxane matrix

Electrochemical properties of a thin-film nanocomposite silicon-carbon matrix-tungsten carbide deposited onto pyroceramics (sitall) substrate are studied by potentiodynamic curves and electrochemical impedance spectroscopy. Transfer coefficients in model redox system [Fe(CN)(6)](3-/4-) are measured. With the decreasing of the films' electrical resistance, their experiment behavior gradually changed from that of poor conductor till nearly metal-like one. In particular, the electrode differential capacitance increases, which is explained by the increase in the number of conducting metal-containing clusters in the film bulk and at the film/electrolyte solution interface. Some specific features of the complex-plane plots of impedance spectra are tentatively explained by the adsorption at the nanocomposite surface elements.