One-step electrochemical deposition of thin film titanium suboxide in basic titanyl sulfate solution at room temperature

• Published in: Journal of solid state electrochemistry Vol. 24; no. 4; pp. 975 - 986
• Main Authors: Ertekin, Zeliha, Pekmez, Nuran Özçiçek, Pekmez, Kadir
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2020; Springer Nature B.V
• Subjects: Acetonitrile; Ammonium hydroxide; Analytical Chemistry; Cathodic coating (process); Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Composition; Condensed Matter Physics; Electrochemical analysis; Electrochemical impedance spectroscopy; Electrochemistry; Electrolysis; Energy Storage; Original Paper; Physical Chemistry; Room temperature; Spectrum analysis; Substrates; Thin films; Titanium oxides; Thin films; Magnéli phase; Electrodeposition; Titanium suboxide; Electrochemical impedance spectroscopy
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-020-04555-9

This study reports direct electrodeposition of TiO x 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 Ti 3 O 5 (βTi 3 O 5 , λTi 3 O 5 , and ɣTi 3 O 5 ) and Ti 4 O 7 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 TiO x 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 TiO x films on ITO electrode is carried out at room temperature by a cost-effective and one-step method in basic acetonitrile solution.