Study of the Adsorption of Dicarboxylic Acids on Titanium Dioxide in Aqueous Solution

The photodegradation processes using semi-conductor like TiO₂ as a catalyst, provide new methods for waste water treatment. In this method the step of adsorption of organic compounds on the semi-conductor surface could have a prominent influence. In this work we describe the results of the study of the dicarboxylic acids adsorption on TiO₂ (P25) in aqueous phase. The Langmuir model gives a good representation of the adsorption of the studied organic diacids. The maximum adsorption capacities are close to 7.10^–5 mol/g for the four studied diacids. The diffuse reflectance infrared spectroscopy (IRFT-DRIFT mode) of loaded TiO₂ enables to demonstrate the formation of a dicarboxylate film on the semi-conductor surface.