Electrochemistry of TiF4 in 1-butyl-2,3-dimethylimidazolium tetrafluoroborate

Electrochemical behaviour of Ti(IV) species in the ionic liquid (IL) 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (BMMImBF4) was studied by means of chronopotentiometry (CP) and cyclic voltammetry (CV) in melts with different concentrations of TiF4 (2–35 mol%) within a temperature range of 65–180 °C. The electrochemical reduction of Ti(IV) was suggested to proceed via the sequence of one-electron steps with the formation of poorly soluble low valence intermediates (LVI). LVIs undergo further solid-state electrochemical reduction to Ti metal. Thin Ti coatings on a Pt substrate were thus obtained and characterized by ESEM method. FTIR spectroscopy was used for identification of the electrochemical active species of Ti(IV). The reaction 2BF4− + TiF4 ⇔ TiF62− + 2BF3↑ takes place in the concentrated solutions of TiF4 at elevated temperatures.