The photodegradation of the azo dye Acid Red 1 (AR1), but not its photomineralization, on fluorinated titanium dioxide is faster than on unmodified TiO2, while the rate of formic acid (FA) photocatalytic degradation is lower. The formation of H2O2, generated by reduction of O2 by conduction band electrons also on F-TiO2, is inhibited during AR1 photodegradation in the presence of F- because of the reduced interfacial electron transfer, while the higher concentration of H2O2 detected during FA photodegradation is due to a shielding effect of fluoride. The OH radical scavengers 2-propanol and formic acid induce a decrease in AR1 photodegradation, more pronounced on F-TiO2, evidencing the key role of hydroxyl radicals. Thus, the rate of photocatalytic degradation of substrates with a high affinity towards hydroxyl radical is enhanced on F-TiO2.
Photodegradation of an azo dye and hydrogen peroxide evolution on fluorinated titanium dioxide / M. Mrowetz, E. Selli - In: Photocatalytic and advanced oxidation processes for treatment of air, water, soil and surfaces / [a cura di] D.F. Ollis, H. Al-Ekabi. - London (Ontario, Canada) : The University of Western Ontario, 2005. - ISBN 0-9738746-0-0. - pp. 102-109
Photodegradation of an azo dye and hydrogen peroxide evolution on fluorinated titanium dioxide
M. MrowetzPrimo
;E. SelliUltimo
2005
Abstract
The photodegradation of the azo dye Acid Red 1 (AR1), but not its photomineralization, on fluorinated titanium dioxide is faster than on unmodified TiO2, while the rate of formic acid (FA) photocatalytic degradation is lower. The formation of H2O2, generated by reduction of O2 by conduction band electrons also on F-TiO2, is inhibited during AR1 photodegradation in the presence of F- because of the reduced interfacial electron transfer, while the higher concentration of H2O2 detected during FA photodegradation is due to a shielding effect of fluoride. The OH radical scavengers 2-propanol and formic acid induce a decrease in AR1 photodegradation, more pronounced on F-TiO2, evidencing the key role of hydroxyl radicals. Thus, the rate of photocatalytic degradation of substrates with a high affinity towards hydroxyl radical is enhanced on F-TiO2.Pubblicazioni consigliate
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