Surface Complexation of Catechol to Metal Oxides: An ATR-FTIR, Adsorption, and Dissolution Study

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• 作者：Heather Gulley-Stahl ; Patrick A. Hogan ; II ; Whitney L. Schmidt ; Stephen J. Wall ; Andrew Buhrlage ; Heather A. Bullen
• 刊名：Environmental Science & Technology
• 出版年：2010
• 出版时间：June 1, 2010
• 年：2010
• 卷：44
• 期：11
• 页码：4116-4121
• 全文大小：209K
• 年卷期：v.44,no.11(June 1, 2010)
• ISSN：1520-5851

文摘

The interaction of catechol with chromium(III) oxide (Cr₂O₃), manganese dioxide (MnO₂), iron(III) oxide (Fe₂O₃), and titanium dioxide (TiO₂) was evaluated as a function of pH conditions (pH 3−10) and ionic strength using a combined approach of bulk adsorption, attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), and dissolution analysis. Adsorption of catechol showed a strong pH-dependent behavior with the metal oxides, remaining constant under acidic−neutral pH (3−7) and increasing under more basic conditions. In situ ATR-FTIR measurements indicate that catechol binds predominately as an outer-sphere complex on MnO₂ and as an inner-sphere complex on Fe₂O₃, TiO₂, and Cr₂O₃ substrates. Catechol complexation on Fe₂O₃, TiO₂, and Cr₂O₃ promotes dissolution at pH >5, whereas MnO₂ dissolution occurs under acidic and basic conditions (pH 3−10).