Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, South Korea.
Phys Chem Chem Phys. 2020 Apr 14;22(14):7537-7545. doi: 10.1039/c9cp05581a. Epub 2020 Mar 27.
Understanding how electrons and protons move in a coupled manner and affect one another is important to the design of proton-electron conductors and achieving biological transport in synthetic materials. In this study, a new methodology is proposed that allows for the quantification of the degree of coupling between electrons and protons in tyrosine-rich peptides and metal oxide hybrid films at room temperature under a voltage bias. This approach is developed according to the Onsager principle, which has been thoroughly established for the investigation of mixed ion-electron conductors with electron and oxide ion vacancies as carriers at high temperatures. Herein, a new device platform using electron-blocking electrodes provides a new strategy to investigate the coupling of protons and electrons in bulk materials beyond the molecular level investigation of coupled proton and electron transfer. Two Onsager transport parameters, α* and σ', are obtained from the device, and the results of these transport parameters demonstrate that the coupled transport of electrons and protons inside the hybrid film plays an important role in the macroscopic-scale conduction. The results suggest that an average of one electron is dragged by one proton in the absence of a direct driving force for electron movement ∇η.
理解电子和质子如何以耦合的方式移动并相互影响，对于质子-电子导体的设计和在合成材料中实现生物传输至关重要。在这项研究中，提出了一种新的方法，该方法可以在室温下对电压偏置下富酪氨酸肽和金属氧化物混合薄膜中电子和质子之间的耦合程度进行量化。该方法是根据昂萨格原理开发的，该原理已经在高温下作为载流子的混合离子-电子导体中电子和氧化物离子空位的研究中得到了充分的建立。在此，使用电子阻挡电极的新器件平台提供了一种新策略，用于研究大块材料中质子和电子的耦合，超出了对耦合质子和电子转移的分子水平研究。从器件中获得了两个昂萨格输运参数α*和σ'，这些输运参数的结果表明，混合薄膜内部电子和质子的耦合输运在宏观尺度传导中起着重要作用。结果表明，在不存在直接电子运动驱动力∇η的情况下，一个质子平均拖动一个电子。
