Immobilization of crystallized photocatalysts on ceramic paper by titanium(IV) ethoxide and photocatalytic decomposition of phenol

A simple method of persistent immobilization was developed for the fixing of highly efficient precrystallized (or even doped) titania (TiO2) based photocatalysts. TiO2 nanoparticles (Aeroxide P25 and VLP7000) were immobilized on the surface of Al2O3-based ceramic paper. For the immobilization, a titanium alkoxide (Ti(OEt)4) was applied as a fixing agent. This type of immobilization resulted in a photocatalytically active surface, which was used in fixed-bed flow reactors through the application of different forms of artificial or solar irradiation to activate the TiO2. To verify the stability, the decomposition of phenol was repeatedly measured on the same TiO2-covered ceramic paper; the photocatalytic performance proved to remain constant throughout five 2-h cycles. The potential for application on an industrial scale was demonstrated by a pilot-plant-scale flow reactor. The developed immobilization method is a simple technique that can be used to investigate the long-term efficiency of novel TiO2 samples, or can be applied in real air/water treatments. © 2014 Akadémiai Kiadó, Budapest, Hungary