Yan Minliang, Bowman Zaya, Knepp Zachary J, Peterson Aiden, Fredin Lisa A, Morris Amanda J
Macromolecules Innovation Institute, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, United States.
Department of Chemical Engineering and Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, United States.
J Phys Chem Lett. 2024 Dec 5;15(48):11919-11926. doi: 10.1021/acs.jpclett.4c01674. Epub 2024 Nov 21.
Redox hopping is the primary method of electron transport through redox-active metal-organic frameworks (MOFs). While redox hopping adequately supports the electrocatalytic application of MOFs, the fundamental understandings guiding the design of redox hopping MOFs remain nascent. In this study, we probe the rate of electron and hole transport through a singular MOF scaffold to determine whether the properties of the MOF promote the transport of one carrier over the other. A redox center, [Ru(bpy)(bpy-COOH)], where bpy = 2,2'-bipyridine and bpy-COOH = 4-carboxy-2,2'-bipyridine, was anchored within NU-1000. The electron hopping coefficients () and ion diffusion coefficients () were calculated via chronoamperometry and application of the Scholz model. We found that electrons transport more rapidly than holes in the studied MOF. Interestingly, the correlation between and self-exchange rate built in previous research predicted reversely. The contradicting result indicates that spacing between the molecular moieties involved in a particular hopping process dominates the response.
氧化还原跳跃是电子通过氧化还原活性金属有机框架（MOF）进行传输的主要方式。虽然氧化还原跳跃充分支持了MOF的电催化应用，但指导氧化还原跳跃MOF设计的基本认识仍处于起步阶段。在本研究中，我们探究了电子和空穴通过单个MOF支架的传输速率，以确定MOF的性质是否促进一种载流子相对于另一种载流子的传输。一个氧化还原中心[Ru(bpy)(bpy-COOH)]（其中bpy = 2,2'-联吡啶，bpy-COOH = 4-羧基-2,2'-联吡啶）被锚定在NU-1000内。通过计时电流法并应用朔尔茨模型计算了电子跳跃系数（）和离子扩散系数（）。我们发现在所研究的MOF中电子传输比空穴更快。有趣的是，先前研究中建立的与自交换速率之间的相关性预测结果相反。这一矛盾结果表明，特定跳跃过程中涉及的分子部分之间的间距主导了响应。
