Iodide/triiodide electrochemistry in ionic liquids: Effect of viscosity on mass transport, voltammetry and scanning electrochemical microscopy
Iodide/triiodide electrochemistry in ionic liquids: Effect of viscosity on mass transport, voltammetry and scanning electrochemical microscopy
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DOI：
10.1016/j.electacta.2011.03.108
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发表时间：
2011-12-01
影响因子：
6.6
通讯作者：
Walsh, Darren A.
中科院分区：
文献类型：
--
作者：
Ejigu, Andinet;Lovelock, Kevin R. J.;Walsh, Darren A.
采用循环伏安法、计时电流法和扫描电化学显微镜（SECM）研究了I（-）/I（3）（-）在离子液体中的电化学行为。电解质为1-烷基-3-甲基咪唑双三氟甲磺酰亚胺[C（n）C（1）Im][Tf（2）N]，离子液体（其中n = 2、4和8）和I（-）通常以约11 mM的浓度加入。在循环伏安法期间，由于I（-）/I（3）（-）氧化还原对的氧化和还原以及I（3）（-）/I（2）的氧化/还原，在每种离子液体中观察到两组峰，氧化还原电对使用计时电流法测定的I（-）和I（3）（-）的扩散系数随着温度的升高而升高，并且随着离子液体粘度的升高而降低。用I（-）/I（3）（-）氧化还原电对测定了离子液体粘度对超微电极伏安法的影响。稳态行为观察到在1.3 μ m的UME在缓慢的伏安扫描速率和稳态SECM反馈方法曲线也得到了在1.3 μ m的Pt SECM提示，只要提示接近速度是足够低的。(C)2011爱思唯尔有限公司版权所有。
The electrochemistry of I(-)/I(3)(-) was studied in ionic liquids using a combination of cyclic voltammetry, chronoamperometry and scanning electrochemical microscopy (SECM). The electrolytes were 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C(n)C(1)Im][Tf(2)N], ionic liquids (where n = 2,4 and 8) and I(-) was typically added at a concentration of approximately 11 mM. During cyclic voltammetry, two sets of peaks were observed in each ionic liquid due to oxidation and reduction of the I(-)/I(3)(-) redox couple and oxidation/reduction of the I(3)(-)/I(2) redox couple. The diffusion coefficients of I(-) and I(3)(-), as determined using chronoamperometry, increased with increasing temperature and decreased with increasing ionic liquid viscosity. The effect of ionic liquid viscosity on ultramicroelectrode (UME) voltammetry was also determined using the I(-)/I(3)(-) redox couple. Steady-state behaviour was observed at 1.3 mu m UMEs at slow voltammetric scan rates and steady-state SECM feedback approach curves were also obtained at a 1.3 mu m Pt SECM tips, provided that the tip approach speed was sufficiently low. (C) 2011 Elsevier Ltd. All rights reserved.