Scaling in Nonstationary Voltammetry Representations
Abstract
Despite the widespread use of voltammetry for a range of chemical, biological, environmental, and industrial applications, there is still a lack of understanding regarding the functionality between the applied voltage and the resulting patterns in the current response. This is due to the highly nonlinear relation between the applied voltage and the nonstationary current response, which casts a direct association nonintuitive. In this Article, we focus on large-amplitude/high-frequency ac voltammetry, a technique that has shown to offer increased voltammetric detail compared to alternative methods, to study heterogeneous electrochemical reaction-diffusion cases using a nonstationary time-series analysis, the Hilbert transform, and symmetry considerations. We show that application of this signal processing technique minimizes the significant capacitance contribution associated with rapid voltammetric measurements. From a series of numerical simulations conducted for different voltage excitation parameters as well as kinetic, thermodynamic, and mass transport parameters, a number of scaling laws arise that are related to the underlying parameters/dynamics of the process. Under certain conditions, these observations allow the determination of all underlying parameters very rapidly, experiment duration typically ≤1 s, using standard electrode geometries and without any a priori assumptions regarding their value. The theoretical results derived from this analysis are compared to experiments with an outer-sphere electron-transfer species, Ru(NH_3)_6^(2+/3+), on different electrode materials, and the determined parameters are in excellent agreement with published values.
Additional Information
© 2007 American Chemical Society. Received: June 13, 2007; In Final Form: August 9, 2007. Publication Date (Web): November 29, 2007. This article is dedicated to the memory of Prof. Dr. M. John Lever for supporting this research. C.A.A. thanks the EPSRC for the financial support as well as Dr. M. Barahona and Dr. A. A. Bharath for CPU time.Attached Files
Supplemental Material - jp074585wsi20070809_114747.pdf
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Additional details
- Eprint ID
- 77707
- DOI
- 10.1021/jp074585w
- Resolver ID
- CaltechAUTHORS:20170524-103913395
- Engineering and Physical Sciences Research Council (EPSRC)
- Created
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2017-05-24Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field