Photocatalytic activity of organic-capped anatase TiO2 nanocrystals in homogeneous organic solutions

Organic-capped anatase TiO2 nanocrystals were tested for the photocatalyzed degradation of a target compound, the textile dye Uniblue A, in homogeneous organic solutions. The photocatalytic activities of nearly spherical and rod-like titania nanoparticles under UV irradiation were comparatively investigated with reference to their bulk commercial counterpart, TiO2 Degussa P25. Preliminary data clearly show that different degradation paths can be initiated, depending on the size of the titania particles, on the nature of the reaction medium and on the presence of dissolved oxygen. The fast reductive decomposition of the conjugated ring structure of Uniblue A appeared to be the dominant pathway in the presence of nanosized TiO2, even in aerated solutions, while the overall photocatalytic efficiency was found not to be affected by the nanocrystals morphology. (C) 2003 Elsevier B.V. All rights reserved.