Changes of electrochemical properties of polypyrrole when synthesized in a room-temperature ionic liquid
Changes of electrochemical properties of polypyrrole when synthesized in a room-temperature ionic liquid
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DOI：
10.1016/j.matchemphys.2014.04.015
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发表时间：
2014-09
影响因子：
4.6
通讯作者：
C. Dalmolin;S. Biaggio;N. Bocchi;R. Rocha‐Filho
中科院分区：
文献类型：
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作者：
C. Dalmolin;S. Biaggio;N. Bocchi;R. Rocha‐Filho
以室温离子液体（RTIL）1-丁基-3-甲基咪唑四氟硼酸盐（BMIM BF 4）为电解液，在Pt基底上电合成了聚吡咯（PPy）薄膜，并对所得PPy电极进行了电化学表征.采用电化学阻抗谱（EIS）研究了RTIL法和传统乙腈/锂盐体系制备的聚吡咯在1.0 M LiBF 4碳酸丙烯酯溶液中2.0-4.0 V（vs. Li/Li+）的充放电行为.虽然在RTIL中获得的PPy的比容量的减少被观察到，相比于在乙腈电解质中合成的PPy膜，其计时电位曲线在2.7 V区域呈现平台。考虑到对于大多数导电聚合物阴极通常观察到该分布的线性降低，这是显著的结果。在BMIM BF 4中制备的PPy薄膜呈球形形貌，纳米粒子的特殊排列构成了球形形貌; EIS结果表明，这种纳米结构可能有助于更好地定义PPy充放电过程中的氧化还原特性，因为它发生在一些金属氧化物的有序结构中。
The room-temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium tetrafluoroborate, BMIM BF4, was employed as electrolyte in the electrosynthesis of thin polypyrrole (PPy) films on a Pt substrate, and the resulting PPy electrodes were electrochemically characterized. Electrochemical impedance spectroscopy (EIS) was used to comparatively investigate the electric behavior of PPy produced in the RTIL and the one produced in a traditional acetonitrile/lithium salt system, and charge–discharge curves in the range 2.0–4.0 V (vs. Li/Li+) were obtained in a 1.0 M LiBF4propylene carbonate solution. Although a reduction of the specific capacity for the PPy obtained in the RTIL was observed, compared to that of the PPy film synthesized in the acetonitrilic electrolyte, its chronopotentiometric profile presented a plateau in the 2.7 V region. This is a remarkable result, considering that a linear decrease in this profile is usually observed for the majority of conducting polymer cathodes. PPy films obtained in BMIM BF4presented globular morphology, with a special arrangement of nanoparticles constituting the globules; the EIS results indicated that this nanoscale structure may be contributing to a better definition of the redox characteristics during the PPy charge–discharge processes, as it happens for the well-organized structure of some metal oxides.