电输运谱在原位电化学界面测量应用中的最新进展

Recent Advances in Electrical Transport Spectroscopy for the in Situ Measurement of Electrochemical Interfaces

电化学/电催化技术是实现能源高效转化与储存的重要手段,并已经发展成为一个国际前沿领域。如今日渐深入的电催化研究开始要求更精确且多维度的电化学界面信息,从而指导实现电化学体系的优化,而这往往依赖于一些原位表征方法的发展和应用。电输运谱(electrical transport spectroscopy,ETS)是一种新兴的基于芯片平台的电化学原位表征技术,它可以实现电势扫描条件下电化学信号和电极材料电输运性质的同时获取。本文首先介绍了基于铂纳米线微纳器件的ETS信号原理(吸附现象导致的表面电子散射)和器件制作流程、几个典型电催化反应过程中铂表面状态的演变,以及电解质离子竞争吸附对铂催化氧还原反应动力学过程的影响。由于与电化学体系的高度匹配,ETS可应用于不同结构及金属类型材料体系(金和铂纳米颗粒)。金和铂表现出显著不同的离子吸附现象,尤其是对于弱吸附离子(高氯酸根和硫酸根)。通过电输运谱还可实时监测电化学过程中材料的相变及电子性质的变化。于是,ETS可被用于监测和实现二维材料电化学可控插层,理解电催化剂在电催化过程中的相变机制以及相变过程如何影响电催化活性,揭示二维半导体催化剂材料电催化过程的自门控效应。此外,ETS还被应用于生物电化学体系,探索电化学过程中的细胞导电机制。最后,本文对ETS的优点及不足进行总结,展望了ETS在未来电化学领域所面临的挑战和机遇。

Electrochemical/electrocatalytic technology has played a central role in achieving highly efficient energy conversion and storage. To date, the in-depth electrochemical research begins to require accurate and multi-dimensional information of electrochemical interfaces, which usually relies on the application of in situ characterizations. Electrical transport spectroscopy(ETS) is a newly developed measurement strategy based on chip-platform, and provides in situ information of electrochemical interfaces from a novel perspective due to a signal origin that is fundamentally different from typical spectroscopic and electrochemical techniques.In this tutorial review, the working principle and experimental setup of ETS are described in detail with the demonstration of several model electrocatalytic materials, including metal nanoparticle/nanowires, two-dimensional layered materials, nickel based hydroxide/oxyhydroxides and dissimilatory metal-reducing bacteria. The advantages of ETS are summarized, and the future challenges and opportunities that ETS faces are also prospected.