ELECTROCHEMISTRY OF TANTALUM PENTACHLORIDE IN THE ROOM TEMPERATURE IONIC LIQUID 1-BUTYL-3-METHY IMIDAZOLIUM HEXAFLUOROPHOSPHATE

摘要

Electrochemical behavior of 0.25M tantalum pentachloride on platinum substrate was investigated in the 1-butyl-3-methy imidazolium hexafluorophosphate ([Bmim]PF_6) by cyclic voltammetry, chronoamperometry. Cyclic voltammetrys of tantalum pentachloride in the employed ionic liquid at 100°C exhibit four reduction peaks, the first reduction peak contributes to the reduction of trichloride anion ((Cl_3)~-) at -0.4V vs. Pt, the second corresponds to the reduction of the tantalum (V) to tantalum (III) at -0.9V vs. Pt, the third is attributed to the reduction of the tantalum (III) to tantalum metal at -1.25V vs. Pt and the fourth is the formation of various tantalum subchlorides at -1.6V vs. Pt. The results have shown that the electrodeposition of tantalum from tantalum pentachloride in [Bmim]PF_6 is quite complicated process, but tantalum can be electrodeposited in thin layers.