在金属含有金属有机框架薄膜中的电子和离子扩散的独立量化
Paula J Celis-Salazar1, Meng Cai1, Clark A Cucinell1
1Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24061 , United States.
Journal of the American Chemical Society
|July 5, 2019
概括
这项研究研究了用金属添加的金属有机框架 (MOF) 中的电子和离子扩散. 离子扩散是速度限制的步骤,受MOF组成和电解质选择的优化运输特性的影响.
科学领域:
- 材料科学
- 电化学
- 纳米技术
背景情况:
- 金属有机框架 (MOF) 为各种应用提供可调节的结构.
- 了解MOF中的电荷和离子传输对于电化学设备至关重要.
- 金属兴奋剂引入氧化还原活性并影响运输特性.
研究的目的:
- 为了阐明金属添加MOF薄膜中的电子 (De) 和离子 (Di) 扩散系数.
- 研究不同金属 (Fe,Ru,Os) 和电解质 (TBAPF6,TBATFAB) 对运输的影响.
- 建立结构功能关系以优化基于MOF的电化学系统.
主要方法:
- 在M-NU-1000 (M=Fe,Ru,Os) 薄膜上进行了时空测量 (I vs t).
- 使用了两种电解质,即四甲六酸 (TBAPF6) 和四甲四酸 (pentafluorophenyl) (TBATFAB).
- 对实验数据应用了固态电压测量的理论模型.
主要成果:
- 在三个电化学转化阶段,离子扩散被确定为速度决定的步骤.
- 电子扩散 (De) 与PF6相对离子增加了Fe< Ru< Os的顺序.
- 与TBAPF6相比,TBATFAB电解质的离子扩散 (Di) 和可比电子扩散 (De) 一般较高,这是由于离子配对较弱的原因.
结论:
- 金属的身份和电解质的选择对MOF中的电子和离子运输有重大影响.
- 通过将快速自我交换的分子部分结合在一起的策略,可以有效调节电子传输速率.
- 这些发现为设计具有量身定制的电化学性能的MOF提供了基础.
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