原位衰减全反射红外光谱电化学 (ATR-IR-SEC) 用于表征近表面掺杂硅 ATR 晶体工作电极上的分子氧化还原过程,The Journal of Physical Chemistry C

当前位置： X-MOL 学术 › J. Phys. Chem. C › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

原位衰减全反射红外光谱电化学 (ATR-IR-SEC) 用于表征近表面掺杂硅 ATR 晶体工作电极上的分子氧化还原过程
The Journal of Physical Chemistry C ( IF 3.3 ) Pub Date : 2023-03-15 , DOI: 10.1021/acs.jpcc.2c08991
Samuel R. Bottum ₁ , Taylor S. Teitsworth ₁ , Qi Han ₁ , Andre D. Orr ₁ , Jin-Sung Park ₁ , Xiaofan Jia ₂ , Chiara Cappuccino ₃ , Bobby H. Layne ₃ , Nilay Hazari ₂ , Javier J. Concepcion ₃ , Carrie L. Donley ₄ , Dmitry E. Polyansky ₃ , Matthew R. Lockett ₁ , James F. Cahoon ₁ , David C. Grills ₃

Affiliation

原位中红外光谱是了解 CO ₂还原机制（CO ₂R) 催化剂，因为它能够直接检测催化中间体和产物。此外，光谱电化学 (SEC)，即光谱与电化学的结合，允许光谱变化与施加的电势相关联，以揭示通常与光电化学反应相关的电势依赖性中间体。由窄带隙半导体（如硅 (Si)）和共价键连接的分子催化剂组成的混合光电极是用于日光驱动催化的有前途的平台，但催化机制的表征在光电化学条件下具有挑战性，特别是当催化剂以单层或更低的浓度存在。这里，我们开发了一种新策略，使用多次反射衰减全反射红外光谱 (ATR-IR) 结合电化学来表征在施加电位下直接与半导体表面集成的催化剂。我们表明，通过晶体表面顶部~100 至 200 nm 的表面近端 n 型或 p 型掺杂，Si ATR 晶体可以同时用作 ATR-IR-SEC 的内部反射元件和半导体工作电极测量。近表面掺杂策略产生具有出色红外透明度的准等势表面，如果晶体被均匀掺杂，该表面会受到自由载流子吸收的影响。这种方法允许在不进行修改的情况下直接探测具有催化活性的功能化表面，并克服了在 Si ATR 晶体上使用单独沉积的工作电极的其他策略的信噪比限制。概念验证 ATR-IR-SEC 光谱分别在 Re 基和 Ru 基过渡金属羰基络合物单层的还原和氧化过程中收集，验证了该技术探测与 CO 相关的氧化还原过程的可行性_{Si 电极表面上的2} R 催化剂具有高灵敏度。

"点击查看英文标题和摘要"

In Situ Attenuated Total Reflectance Infrared Spectroelectrochemistry (ATR-IR-SEC) for the Characterization of Molecular Redox Processes on Surface-Proximal Doped Silicon ATR Crystal Working Electrodes

In situ mid-infrared spectroscopy is a powerful technique for understanding the mechanism of CO₂ reduction (CO₂R) catalysts because it enables the direct detection of catalytic intermediates and products. Moreover, spectroelectrochemistry (SEC), the coupling of spectroscopy with electrochemistry, allows spectroscopic changes to be correlated with applied potentials to reveal potential-dependent intermediates that are often relevant to photoelectrochemical reactions. Hybrid photoelectrodes, composed of a narrow bandgap semiconductor, like silicon (Si), with a covalently linked molecular catalyst, are a promising platform for sunlight-driven catalysis, but characterization of the catalytic mechanism(s) is challenging under photoelectrochemical conditions, particularly when the catalyst is present in monolayer or less concentrations. Here, we have developed a new strategy to use multiple-reflection attenuated total reflectance IR spectroscopy (ATR-IR) coupled with electrochemistry to characterize catalysts directly integrated with a semiconductor surface under applied potential. We show that by surface-proximal n-type or p-type doping of the top ∼100 to 200 nm of the crystal surface, Si ATR crystals can be used simultaneously as the internal reflection element and semiconductor working electrode for ATR-IR-SEC measurements. The surface-proximal doping strategy yields a quasi-equipotential surface with excellent infrared transparency that would have been compromised by free carrier absorption if the crystal was uniformly doped. This approach permits the catalytically active functionalized surface to be directly probed without modification and overcomes signal-to-noise limitations of other strategies that use separately deposited working electrodes on Si ATR crystals. Proof-of-concept ATR-IR-SEC spectra were collected during the reduction and oxidation of monolayers of Re- and Ru-based transition-metal carbonyl complexes, respectively, verifying the viability of the technique to probe redox processes associated with CO₂R catalysts on Si electrode surfaces with high sensitivity.

更新日期：2023-03-15

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南