ABSTRACT
This chapter provides data from various studies on the photodegradation of phenol and of nitrophenol isomers in aqueous oxygenated dispersions of TiO2 that was obtained from various sources and preparations. Two different types of photoreactors were used for the photodegradation runs. The first type, which consisted of Pyrex glass flasks placed in a Solarbox, was used for runs aimed only at checking the photoactivity of various powders. The second type of photoreactor was a biannular Pyrex batch photoreactor containing 1.5 L of aqueous dispersion. Similar kinetics were found for phenol and for the nitrophenol isomers. The most important result was that the maximum in photoactivity for the decomposition of phenol was found in the heterogeneous system and when H2O2 and O2 were simultaneously present. In the presence of helium, anatase was slightly more active than rutile. The commercial TiO2 specimens, consisting of the anatase phase, included the Degussa P25 specimen.
