Adsorption Studies of Methyl Orange on Nanostructured Powder of TiO2

Abstract

The photocatalytic degradation of methyl orange in aqueous suspensions of nanoporous TiO₂ powder under a variety of factors: pH, amount of TiO₂, illumination time, and concentration of MO was discussed. We investigated the adsorption of methyl orange on TiO₂ under visible light (ë > 420 nm), as a primary step in a photodegradation (in UV). Since for low concentration of MO, the heat evolved during adsorption was -29.638 kJ mol. 1, the forces between the adsorbent and adsorbate appear to be mainly van der Waals forces. The Freundlich and Langmuir equations are used for modeling.