Abstract :
In this paper, we reported an improved preparation of 3-ethyl-1-methylimidazolium trifluoroacetate (EMITA), which proceeded via
efficient reaction of 1-methylimidazole and ethyl trifluoroacetate under solvent-free conditions using Teflon-lined, stainless steel autoclaves.
It was shown that the procedure was simple and eco-friendly. The apparent diffusion coefficients of triiodide and iodide in binary
ionic liquids, EMITA and 1-methyl-3-propylimidazolium iodide (MPII) with various weight ratios, were demonstrated by cyclic voltammetry
using a Pt ultramicroelectrode. It was found that the apparent diffusion coefficients of triiodide slightly increased and those of
iodide decreased with the weight ratio increase of EMITA and MPII. The dye sensitized solar cells with the electrolyte, which was composed
of 0.13 M I2, 0.10M LiI, 0.50 M 4-tert-butylpyrdine in the binary ionic liquid electrolyte of EMITA and MPII (weight ratio 1:2),
gave short circuit photocurrent density of 7.88 mA cm 2, open circuit voltage of 0.61 V, and fill factor of 0.67, corresponding to the photoelectric
conversion efficiency of 3.22% at the illumination (Air Mass 1.5, 100 mW cm 2).
2008 Published by Elsevier Ltd.
