Maroo Sonal, Yu Yun, Taniguchi Takashi, Watanabe Kenji, Bediako D Kwabena
Department of Chemistry, University of California, Berkeley, California 94720, United States.
International Center for Materials Nanoarchitectonics and Research Center for Functional Materials, National Institute for Materials Science, Tsukuba 305-0044, Japan.
ACS Nanosci Au. 2023 Feb 20;3(3):204-210. doi: 10.1021/acsnanoscienceau.2c00064. eCollection 2023 Jun 21.
The electronic properties of electrode materials play a crucial role in defining their electrochemical behavior in energy conversion and storage devices. The assembly of van der Waals heterostructures and fabrication into mesoscopic devices enable the dependence of an electrochemical response on electronic properties to be systematically interrogated. Here, we evaluate the effect of charge carrier concentration on heterogeneous electron transfer at few-layer MoS electrodes by combining spatially resolved electrochemical measurements with field-effect electrostatic manipulation of band alignment. Steady-state cyclic voltammograms and finite-element simulations reveal a strong modulation of the measured electrochemical response for outer-sphere charge transfer at the electrostatic gate voltage. In addition, spatially resolved voltammetric responses, obtained at a series of locations at the surface of few-layer MoS, reveal the governing role of in-plane charge transport on the electrochemical behavior of 2D electrodes, especially under conditions of low carrier densities.
电极材料的电子特性在决定其在能量转换和存储设备中的电化学行为方面起着至关重要的作用。范德华异质结构的组装以及将其制备成介观器件，使得能够系统地研究电化学响应与电子特性之间的相关性。在此，我们通过将空间分辨电化学测量与能带排列的场效应静电操纵相结合，评估了电荷载流子浓度对少层MoS电极上异质电子转移的影响。稳态循环伏安图和有限元模拟表明，在静电栅极电压下，测量到的外层电荷转移的电化学响应受到强烈调制。此外，在少层MoS表面一系列位置获得的空间分辨伏安响应表明，面内电荷传输对二维电极的电化学行为起主导作用，尤其是在低载流子密度条件下。
