Photocatalytic degradation of gaseous toluene by using immobilized titania/silica on aluminum sheets.
OBJECTIVE
The aim of this study was to prepare a highly active immobilized titania/silica photocatalyst and to test its performance in situ toward degradation of toluene as one of the major toxic indoor contaminants.


METHODS
In this work, two different titania layers immobilized on Al sheets were synthesized via low temperature sol-gel method employing presynthesized highly active titania powders (Degussa P25 and Millennium PC500, mass ratio 1:1): (a) with a silica/titania binder and a protective layer and (b) without the binder. The photocatalysts were characterized by X-ray diffraction, nitrogen sorption measurements, scanning electron microscopy (SEM), infrared spectroscopy, and UV-vis diffuse reflectance spectroscopy (DRS). The in situ photocatalytic degradation of gaseous toluene was selected as a probe reaction to test photocatalytic activity and to verify the potential application of these materials for air remediation.


RESULTS
Results show that nontransparent highly photocatalytically active coatings based on the silica/titania binder and homogeneously dispersed TiO(2) powders were obtained on the Al sheets. The crystalline structure of titania was not altered upon addition of the binder, which also prevented inhomogeneous agglomeration of particles on the photocatalyst surface. The photoactivity results indicate that the adsorption properties and photocatalytic activity of immobilized photocatalysts with the silica/titania binder and an underlying protective layer were very effective and additionally, they exhibited considerably improved adhesion and uniformity.


CONCLUSIONS
We present a new highly photocatalytically active immobilized catalyst on a convenient metallic support, which has a potential application in an air cleaning device.
Laboratory for Environmental Research, University of Nova Gorica, Vipavska 13, 5001, Nova Gorica, Slovenia. minoo.tasbihi@ung.si
Minoo
M
Tasbihi
Marko
M
Kete
Ashok M
AM
Raichur
Nataša Novak
NN
Tušar
Urška Lavrenčič
UL
Stangar
D000393:Air Pollutants / Q000737:chemistry*; D000535:Aluminum / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D010083:Oxidants, Photochemical / Q000737:chemistry; D010782:Photolysis; D012822:Silicon Dioxide / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014050:Toluene / Q000737:chemistry*
D000393:Air Pollutants; D010083:Oxidants, Photochemical; C009495:titanium dioxide; D014050:Toluene; D012822:Silicon Dioxide; D000535:Aluminum; D014025:Titanium