Photocatalytic activity of TiO2/SiO2 systems.
Silica-supported TiO(2) powders were synthesized by a wet method under mild conditions. The aim of the work was the preparation of TiO(2)/SiO(2) additives for photocatalytic cements. Three types of commercial SiO(2) were used as supports: Cabot, Axim and Fly Ash. Cabot silica was ultra-pure whereas the other two silica contained different percentages of various oxides. The TiO(2)/SiO(2) samples, denoted TiO(2)/Cabot, TiO(2)/Axim and TiO(2)/Fly Ash, were prepared by boiling suspensions obtained by addition of silica to a solution of TiCl(4) in water (volume ratio 1:10). The photocatalytic activity was evaluated in a gas-solid system both in batch and in continuous reactors using 2-propanol as probe molecule. SEM-EDX analysis revealed that titanium dioxide was quantitatively deposited on silica. TiO(2)/Axim and TiO(2)/Fly Ash were scarcely active whereas a good photoactivity was exhibited by the TiO(2)/Cabot sample both in the batch and in the continuous system. Consequently only the last sample was tested for both NO(x) abatement and for 4-nitrophenol photodegradation in a liquid-solid system.
Bellardita
M
M
Schiavello-Grillone Photocatalysis Group, Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Università di Palermo, Viale delle Scienze, 90128 Palermo, Italy.
Addamo
M
M
Di Paola
A
A
Marcì
G
G
Palmisano
L
L
Cassar
L
L
Borsa
M
M
D002384:Catalysis; D008855:Microscopy, Electron, Scanning; D010777:Photochemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium