The electrochemical behavior of samarium (Sm), europium (Eu), and ytterbium (Yb) was investigated in the hydrophobic room-temperature molten salts based on bis(trifluoromethylsulfonyl)imide (TFSI -) combined with either 1-ethyl-3-methylimidazolium (EMI +) or 1-n-butyl-1-methylpyrrolidinium (BMP +). The redox reactions of Sm(III)/Sm(II), Eu(III)/Eu(II), and Yb(III)/Yb(II) were observed at -1.6, -0.3, and -1.0V vs Ag/Ag(I), respectively. In all cases, the electrode reactions were found to be quasi- or irreversible by the cyclic voltammetry. The diffusion coefficients of these lanthanides were estimated to be ∼10 -8cm 2s -1 by chronoamperometry and chronopotentiometry, indicating that their mobility is rather low, probably due to the complex formation or the strong coulombic interaction with TFSI -. The redox potentials of these divalent and trivalent lanthanide couples suggested that the donor property of TFSI --based room-temperature molten salts was lower than that of other conventional solvents.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry