Physico-Chemical Research Institute, Belarusian State University, 220050, Minsk, Belarus

Keywords: potentiodynamic electrochemical impedance spectroscopy, nonstationary, dynamic frequency response of semiconductor-electrolyte interface, surface, space charge layer capacitance, Mott-Schottky plot, doping density, flatband potential, titanium dioxide anodic film, hydrogen intercalation, double layer capacitance, non-stationary processes in space charge layer, Warburg element, active resistance

Potentiodynamic electrochemical impedance spectroscopy provides extraction of the variable and potential-dependent space charge layer capacitance from potentiodynamic impedance spectra of nonstationary semiconductor-electrolyte interface. The new technique has been applied for acquisition of Mott-Schottky plots of cathodically treated TiO₂ anodic films. Cathodic treatment in 1 M H₂SO₄ increases donor density and flat-band potential of TiO₂. Freshly doped films show hysteresis in the space charge layer capacitance in cyclic potential scans. The subsequent cycling eliminates the hysteresis but preserves the greater part of the doping effect that results from proton intercalation.

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^*Presented at the 4th Baltic Conference on Electrochemistry, Greifswald, 13-16 March 2005