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1499100 
Journal Article 
Titanium dioxide (TiO2)-assisted photocatalytic degradation of volatile organic compounds at ppb level 
Tanizaki, T; Murakami, Y; Hanada, Y; Ishikawa, S; Suzuki, M; Shinohara, R 
2007 
Yes 
Journal of Health Science
ISSN: 1344-9702
EISSN: 1347-5207 
53 
5 
514-519 
English 
WOS:000250790000002 
Titanium dioxide (TiO2)-assisted photodegradation of
volatile organic compounds (VOCs), especially malodorous substances at ppb level in closed air
are reported. As target VOCs we selected acetaldehyde, dimethyl disulfide (DMDS), dimethyl
sulfide (DMS) and methyl mercaptan, because of their toxicity and unpleasant odor at low
concentration in closed air. The initial concentrations were fixed at 0.4-5.0 ppm for
acetaldehyde, 0.03 ppm for DMDS and DMS and 0.02 ppm for methyl mercaptan respectively. A
blacklight UV-Iamp was employed as a light source and the intensity of UV-light was controlled at
1.0 mW/cm(2) (351 nm). The half life of these odorous substances was from 20 min to 120 min and
pseudo-first-order reaction rates were 1.1 X 10(-2) min(-1) (acetaldehyde), 1.4 x 10(-2) min(-1)
(DMDS), 4.8 x 10(-2) min(-1) (DMS) and 8.0 x 10(-3) min(-1) (methyl mercaptan). One of the by-
products of TiO2 photodegradation of acetaldehyde was identified as formaldehyde by liquid
chromatography/mass spectrometry (LC/MS). These basic data of TiO2, photodegradation for odorous
substances will be useful for the construction of an air purification system using TiO2
photodegradation in closed air, for example in living rooms, hospitals and care rooms. 
titanium dioxide-assisted photodegradation; ppb level; malodorous substance