Surface-Enhanced Raman Spectroscopy-Scanning Electrochemical Microscopy: Observation of Real-Time Surface pH Perturbations
Surface-Enhanced Raman Spectroscopy-Scanning Electrochemical Microscopy: Observation of Real-Time Surface pH Perturbations
复制标题
DOI：
10.1021/acs.analchem.1c00888
复制
发表时间：
2021-05-27
影响因子：
7.4
通讯作者：
Rodriguez-Lopez, Joaquin
中科院分区：
文献类型：
--
作者：
Hatfield, Kendrich O.;Gole, Matthew T.;Rodriguez-Lopez, Joaquin
理解和控制电极界面的化学动力学是传感、电催化和能量存储等电化学应用的关键。在这里，我们介绍了共定位表面增强拉曼散射扫描电化学显微镜（SERS-SECM）作为一种多模式的工具，能够同时探测和影响电化学接口在真实的时间。作为演示SERS-SECM的模型系统，我们使用了自组装单层的4-巯基吡啶（4 MPy），一种pH敏感的拉曼指示剂，锚定到作为基底的银纳米颗粒。我们用计时电流法调制表面的局部pH，诱导SECM尖端的析氢反应（HER），并观察到随后的4 MPy拉曼峰高变化。然后，我们在SECM尖端进行HER的循环伏安法，同时每200 ms测量一次Sers光谱，以突出该技术的实时能力。我们的研究结果表明，灵敏地询问和触发化学/电化学动态表面现象的能力。我们希望SERS-SECM将提供在电化学界面上的异质和同质反应之间的联系的见解。
Understanding and controlling chemical dynamics at electrode interfaces is key to electrochemical applications in sensing, electrocatalysis, and energy storage. Here, we introduce colocalized surface-enhanced Raman scattering-scanning electrochemical microscopy (SERS-SECM) as a multimodal tool able to simultaneously probe and affect electrochemical interfaces in real time. As a model system to demonstrate SERS-SECM, we used a self-assembled monolayer of 4-mercaptopyridine (4MPy), a pH sensitive Raman indicator, anchored to silver nanoparticles as a substrate. We modulated the local pH at the surface with chronoamperometry, inducing the hydrogen evolution reaction (HER) at the SECM tip and observed subsequent Raman peak height changes in the 4MPy. We then performed cyclic voltammetry of HER at the SECM tip while measuring SERS spectra every 200 ms to highlight the technique's real-time capabilities. Our results show the capability to sensitively interrogate and trigger chemical/electrochemical dynamic surface phenomena. We hope SERS-SECM will provide insight on the link between heterogeneous and homogeneous reactivity at electrochemical interfaces.