Electrochemical behavior of the hexafluorouranate anion in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide room temperature ionic liquid

摘要

Electrochemical behavior of the hexafluorouranate (UF_6~-) anion in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide (BMImTFSA) has been investigated at 298 K by means of cyclic voltammetry and chronoamperometry. Cyclic voltammograms of a Pt electrode revealed that electrochemical reduction of UF_6~- was an irreversible reaction to UF_6~(2-) with α n_α =0.47. The diffusion coefficient of UF_6~- in BMImTFSA determined by chronoamperometry is 8.7× 10~(-8) cm_2 s-1. The Stokes radius of UF_6~- in BMImTFSA is calculated to be 0.46 nm from the Stokes-Einstein equation using the diffusion coefficient and the viscosity of the melt.