Copyright © 2008 Javier Marugán et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The activity of titania photocatalysts is highly dependent on the synthesis procedure. This work reports a study of the correlation between the photocatalytic activity and the physicochemical and photoelectrochemical properties of sol-gel TiO2 powders and electrodes synthesized using different pH values and temperatures. The activity of the materials has been evaluated using the decolorization of Reactive Orange 16 (RO16) as model reaction. In contrast with the large number of studies reporting the influence of the temperature, our results point out that preparation pH has even more influence on the crystalline phases and the photocatalytic activity of TiO2 powders and photocurrents of the electrodes. However, the effects on the activity and the photocurrents recorded after immobilization on a conducting support do not vary accordingly. Consequently, our results indicate that the measurement of the photocurrent in an electrolyte media is not a good indicator of the photocatalytic activity of the unsupported system.