Mapping of Electrocatalytic Sites on a Single Strand of Carbon Fiber Using Scanning Electrochemical Microscopy (SECM)

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• 作者：Vrushali S. Joshi ; Santosh K. Haram ; Arindam Dasgupta ; G. V. Pavan Kumar
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：May 3, 2012
• 年：2012
• 卷：116
• 期：17
• 页码：9703-9708
• 全文大小：406K
• 年卷期：v.116,no.17(May 3, 2012)
• ISSN：1932-7455

文摘

A novel use of scanning electrochemical microscopy (SECM) to study electrocatalytic heterogeneities present on a single strand of carbon fiber (SSCF) is presented. The SECM investigations on an SSCF have been carried out in a feedback mode using 伪-methyl ferrocene methanol as a redox mediator. Array scan investigations revealed substantial enhancement in the positive feedback response at specific locations on the SSCF. These locations appeared as high-contrast morphological heterogeneities in the optical micrographs. The probe-approach curves, recorded near a variety of predefined locations on the SSCF, were fitted in the analytical expressions. From this analysis, the apparent pseudo-first-order rate constant k_eff for the electron-transfer reaction was estimated. The electroactive locations resulted in a k_eff as high as 0.1 cm s^鈥?. The confocal micro-Raman spectra recorded on the identical portions of the fiber indicated a larger proportion of the distorted sp²-hybridized structure near the electroactive sites and thus implied enhanced local electrocatalytic activity on the fiber.