Insights on the photocatalytic degradation processes supported by TiO2/WO3 systems : the case of ethanol and tetracycline

TiO 2 /WO 3 composites are widely in the literature as engineered systems for photocatalytic and (photo)electrochemical applications, since the presence of WO 3 can promote both visible light absorption and electron transfer phenomena of TiO 2 . The preparation of these system, depending on the preparation method, can also affect the surface feature with respect to TiO 2 , modifying adsorption and performance, as well as the reaction mechanisms. Here, TiO 2 /WO 3 composites were prepared by precipitation of WO 3 onto the TiO 2 surface and characterized in terms of their structural, morphological, optical and surface properties. Raman and IR spectroscopy as well as a marked shift in the isoelectric point support the preferential surface location of WO 3 . Samples were photocatalytically tested towards the degradation of ethanol and of tetracycline and the adsorption and degradation behaviour were studied, suggesting, in both cases, significant variations of the reaction paths by the addition of WO3.