Ba-Ying, Wen and Jun, Yi and Ya-Hao, Wang and Kanagaraj, M and Hua, Zhang and Kathiresan, M and Jian-Feng, Li and Zhong-Qun, Tian (2016) In-situ monitoring of redox processes of viologen at Au(hkl)single-crystal electrodes using electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy. Electrochemistry Communications, 72. pp. 131-134. ISSN 1388-2481

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Abstract

In-situ Raman/SERS studies of molecular adsorption/reaction behaviors at well-defined electrochemical interfaces are important for understanding the fundamentals of electrochemical processes. However, it is still a great challenge to perform such studies on model single-crystal surfaces as the smooth surface cannot support surface plasmon resonance (SPR). In this work, shell-isolated nanoparticle-enhanced Raman spectroscopy was combined with an electrochemical method (EC-SHINERS) to study the adsorption and redox transformation of a resonant molecule viologen HS-8V8H at Au(hkl) single-crystal electrodes. Changes in the molecular structure with potential were identified on different single-crystal surfaces, which explained the transformation process of viologen fromV2+ state to V•+ and then V0. Facet-dependent SERS enhancementwas also observed,which results from the different imaginary part of the dielectric function on Au(111), Au(100) and Au(110), and is supported by the FEM simulations. Furthermore, a nonlinear resonant Raman process has been directly observed in our experiments, which is consistent with the simulation results. These findings increase our understanding of the electrochemical behavior of molecules in model systems.

Item Type:	Article
Uncontrolled Keywords:	SERS; SHINERS; Viologen; Single-crystal Electrochemistry
Subjects:	Electroorganic
Divisions:	UNSPECIFIED
Depositing User:	Dr. N Meyyappan
Date Deposited:	07 Aug 2017 06:56
Last Modified:	07 Aug 2017 06:56
URI:	http://cecri.csircentral.net/id/eprint/3163

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