Minimizing the electrosorption of water from humid ionic liquids on electrodes
Minimizing the electrosorption of water from humid ionic liquids on electrodes
复制标题
最大限度地减少电极上潮湿离子液体中水的电吸附
DOI：
10.1038/s41467-018-07674-0
复制
发表时间：
2018-12-04
影响因子：
16.6
通讯作者：
Feng, Guang
中科院分区：
文献类型：
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作者：
Bi, Sheng;Wang, Runxi;Feng, Guang
在基于离子液体电解质的超级电容器中，少量吸收的水可能会降低电解质的电化学窗口并导致性能下降。如果将离子液体用作涉及溶解的分子物质的电催化的溶剂，也会发生同样的情况。在这项工作中，我们进行分子动力学模拟，与金和碳电极在典型的离子液体，疏水性和亲水性，研究水的电吸附。我们研究了离子液体和电极的疏水/亲水性对离子和电吸附水界面分布的影响。结果表明，使用亲水性离子液体将有助于保持水分子远离带负电荷的电极，即使在大的电极极化。这一结论得到了支持的电化学循环伏安法测量接触潮湿的离子液体的金和碳电极。因此，我们的研究结果表明保护电极免受水电吸附的潜在机制。
In supercapacitors based on ionic liquid electrolytes, small amounts of absorbed water could potentially reduce the electrochemical window of electrolytes and cause performance degradation. The same would take place if ionic liquids are used as solvents for electrocatalysis involving the dissolved molecular species. In this work, we carry out molecular dynamics simulations, with gold and carbon electrodes in typical ionic liquids, hydrophobic and hydrophilic, to study electrosorption of water. We investigate the effects of hydrophobicity/hydrophilicity of ionic liquids and electrodes on interfacial distribution of ions and electrosorbed water. Results reveal that using hydrophilic ionic liquids would help to keep water molecules away from the negatively charged electrodes, even at large electrode polarizations. This conclusion is supported by electrochemical cyclic voltammetry measurements on gold and carbon electrodes in contact with humid ionic liquids. Thereby, our findings suggest potential mechanisms for protection of electrodes from water electrosorption.