Direct electrochemical reduction of titanium dioxide in Lewis basic AlCl sub(3)-1-butyl-3-methylimidizolium ionic liquid

• Published in: Electrochimica acta 2011-10, Vol.56 (24), p.8530-8533
• Main Authors: Zhang, Xiao-Ying, Hua, Yi-Xin, Xu, Cun-Ying, Zhang, Qi-Bo, Cong, Xiao-Bo, Xu, Nan
• Format: Article
• Language: English
• Subjects: Cathodes; Cathodic dissolution; Ionic liquids; Reduction; Reduction (electrolytic); Titanium; Titanium dioxide; Voltammetry
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2011.07.037

The direct electrochemical reduction of titanium dioxide (TiO sub(2)) to metallic titanium at room temperature is firstly studied in Lewis basic AlCl sub(3)-1-butyl-3-methylimidizolium (AlCl sub(3)-BMIC) ionic liquid. In this study, cyclic voltammetry, potentiodynamic polarization, sampled current voltammetry and X-ray photoelectron spectroscopy (XPS) techniques were utilized. Analysis of the cyclic voltammetry suggested that TiO sub(2) film can be reduced to metallic Ti. The sampled current voltammetry was applied to elaborate the reduction mechanism and the results showed that this reduction process may include two steps. When the output potential difference of 2.8 V was applied, a TiO sub(2) cylindrical pellet was partly reduced to metallic Ti. However, due to the very slow reaction rate, there was only about 12 wt% of TiO sub(2) was reduced during the electrolysis time of 48 h. It was predicted that the process for the direct reduction of solid TiO sub(2) would be explained as follows: given enough cathode potential, the reduction happened at the cathode/ionic liquids interface, where the oxygen was ionized, then dissolved in the ionic liquid and discharged at the anode, with the metallic Ti left at the cathode.