Electro-oxidation of Ascorbic Acid by Cobalt Core鈥揝hell Nanoparticles on a H-Terminated Si(100) and by Nanostructured Cobalt-Coated Si Nanowire Electrodes

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• 作者：Liyan Zhao ; Kristine Liao ; Mark Pynenburg ; Louis Wong ; Nina Heinig ; Joseph P. Thomas ; K. T. Leung
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2013
• 出版时间：April 10, 2013
• 年：2013
• 卷：5
• 期：7
• 页码：2410-2416
• 全文大小：345K
• 年卷期：v.5,no.7(April 10, 2013)
• ISSN：1944-8252

文摘

Determination of the concentration of ascorbic acid in a solution has attracted intense recent interest. Here we demonstrate the feasibility of electro-oxidation of ascorbic acid on spherical cobalt core鈥搒hell nanoparticles (10-50 nm dia.) prepared by electrochemical deposition on a H-terminated Si(100) substrate. Depth-profiling X-ray photoelectron spectroscopy reveals that these nanoparticles consist of a metallic cobalt core covered by a Co(OH)₂ shell without any evidence of CoO_x. Glancing-incidence X-ray diffraction studies further show that the metallic Co core consists of a mixture of hexagonal close packed and face centered cubic structures, the relative composition of which can be easily controlled by the deposition potential. We further demonstrate that when these Co nanoparticles are deposited on a high-surface-area electrode as provided by a Si nanowire template, the resulting nanostructured Co-coated Si nanowire electrode offers a promising high-performance sensor platform for ascorbic acid detection.

Keywords:

cobalt core鈭抯hell nanoparticles; electrodeposition; silicon nanowire electrode; SEM; XPS; GIXRD; electro-oxidation of ascorbic acid