The impedance related to the electrochemical hydrogen insertion into WO3 films – On the applicability of the diffusion-trapping model

Impedance analysis of electrochemically prepared WO3 films has been carried out in order to investigate the applicability of the diffusion-trapping model to the analysis of impedance spectra related to electrochemical hydrogen insertion. The impedance spectra measured under different conditions have been analyzed by using CNLS fitting. It has been shown, that the expressions derived for the diffusion-trapping model adequately describe the impedance response of the system. Despite of the great number of adjustable parameters many of them could be determined with a good statistics, and reasonable estimated mean values have been obtained for the others. The reliability of the estimated parameters was checked by comparing the results with existing experimental data.