Electrodeposited Silicate Films: Importance of Supporting Electrolyte

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• 作者：Maryanne M. Collinson ; Daniel A. Higgins ; Roshna Kommidi ; Debbie Campbell-Rance
• 刊名：Analytical Chemistry
• 出版年：2008
• 出版时间：February 1, 2008
• 年：2008
• 卷：80
• 期：3
• 页码：651 - 656
• 全文大小：118K
• 年卷期：v.80,no.3(February 1, 2008)
• ISSN：1520-6882

文摘

Silica and hybrid organic-inorganic films, ca. 100-200nm thick, can be grown on glassy carbon electrodesthrough reactions initiated by electrogenerated hydroxideor hydronium ions in water under reductive and oxidativeconditions, respectively. A variety of different alkoxysilanes (tetramethoxysilane and organoalkoxysilanes) andsupporting electrolytes were used to evaluate whether filmformation takes place on glassy carbon electrodes. Theresults of the study indicate that the acid-base propertiesof the supporting electrolyte are an important factor indetermining whether film formation will take place. Forcathodic electrodeposition, thin films can be formed usingsupporting electrolytes that are close to neutral, such asKCl, KNO₃, and NaClO₄. For anodic electrodeposition,thin films can be formed using supporting electrolytes thatare acidic, such as, KH₂PO₄, HNO₃, H₂SO₄, etc. Theacidity/basicity effects of the electrolytes arise in part fromthe strong dependence of the hydrolysis and condensationrates of the silicon alkoxide precursors on pH.