JOURNAL OF SOLID STATE ELECTROCHEMISTRY, cilt.24, sa.4, ss.975-986, 2020 (SCI-Expanded)
This study reports direct electrodeposition of TiOx thin films on ITO substrate from an acetonitrile solution containing titanyl sulfate and tetra n-butyl ammonium hydroxide. The electrochemical behavior of titanyl sulfate in a basic medium is investigated using cyclic voltammetry. In this medium, different phases and/or compositions containing Ti3O5 (beta Ti3O5, lambda Ti3O5, and gamma Ti3O5) and Ti4O7 are obtained depending on electrolysis potential values (- 1.2 V, - 1.5 V, - 1.7 V, and - 2.0 V). The electrochemical properties of the TiOx coatings obtained from various cathodic potentials are investigated using electrochemical impedance spectroscopy (EIS). Depending on the increase of electrolysis potential values applied, thicker films with lower resistance are formed. The EIS analysis results are compatible with the results of XRD and SEM, which confirms the change of phase content and/or composition in the films obtained at different electrolysis potential values. The estimated band gaps of brownish thin films are obtained between 1.32 and 1.41 eV using UV-vis spectra. Herein the electrochemical deposition of crystalline TiOx films on ITO electrode is carried out at room temperature by a cost-effective and one-step method in basic acetonitrile solution.