Ultrahigh Frequency Voltammetry: Effect of Electrode Material and Frequency of Alternating Potential Modulation on Mass Transport at Hot-Disk Microelectrodes

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• 作者：Andrzej S. Baranski ; Aliaksei Boika
• 刊名：Analytical Chemistry
• 出版年：2012
• 出版时间：February 7, 2012
• 年：2012
• 卷：84
• 期：3
• 页码：1353-1359
• 全文大小：260K
• 年卷期：v.84,no.3(February 7, 2012)
• ISSN：1520-6882

文摘

Ultrahigh frequency voltammetry involves low scan rate voltammetric measurements with microelectrodes polarized by high-frequency large-amplitude alternating potential. The method provides a simple means for studying electrothermal and dielectrophoretic effects, which are important in micro and nanofluidic systems. The method also allows for indirect measurements of electrode impedance at gigahertz frequencies. This increases the upper frequency limit in impedance measurements about 1000 times. In this work we demonstrated, for the first time, that the effect of dielectric relaxation of water can be observed in a simple voltammetric experiment. The paper focuses on the description of electrothermal convection at ac heated disk microelectrodes as a function of frequency and provides a comparison of numerical simulations with experimental results.