Bradley University, Mund- Lagowski Department of Chemistry and Biochemistry, Peoria, IL 61606
The adsorption of humic acid from aqueous solution onto thin films prepared from TiO2 nano-particles is described. The primary technique employed is attenuated total reflectance/Fourier-transform infrared (ATR/FT-IR) spectroscopy in conjunction with a flow-thru, small volume liquid sample cell (“McQuillan cell”). ATR/FT-IR spectroscopy identifies the functional groups of an adsorbed molecule that interact with the surface of a metal oxide thin film. The performance of this technique was verified by comparing ATR/FT-IR spectra recorded for oxalic acid adsorbed onto anatase TiO2 films with previously published results.1 Using 1.5 μm films prepared from 25 nm, anatase TiO2 nano-particles, ATR/FT-IR spectra demonstrate the dependence of humic acid adsorption on TiO2 as a function of pH. Additional studies, including the determination of adsorption isotherms and the application of ultraviolet spectroscopic analysis of humic acid adsorption on dispersed TiO2 nano-particles in aqueous solution, are in progress.
1. Young, A. G.; McQuillan, A. J. Langmuir 2009, 25, 3538-3548.
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