Characterization and activity of visible-light driven TiO2 photocatalyst doped with tungsten.
This research aimed to expand the activity of TiO(2) down to the visible light region by modifying the sol-gel conditions and doping with tungsten. The optimum conditions for calcination temperature, acid type, and heating rate were 200°C, HNO(3), and 1°C/min, respectively. The undoped TiO(2) synthesized under these conditions could significantly absorb the visible light whereas the commercial Degussa P-25 could not. The absorptivity decreased sequentially as the wavelength increased from 400 to 700 nm. Within 6 h of 2-W blue-light illumination, 23% of 0.1 mM 2-chlorophenol was removed. The XRD result showed that the crystalline was anatase phase. The visible-light absorption property of the TiO(2) became even better when doped with tungsten. At the optimum W to TiO(2) ratio of 0.5%, the degradation of 0.1 mM 2-chlorophenol increased to 53% indicating a higher photocatalytic activity. Both crystalline and amorphous TiO(2) could exhibit the photocatalytic activity under the visible light region.
National Center of Excellence for Environmental and Hazardous Waste Management, Chulalongkorn University, Bangkok 10130, Thailand. Thapanun_tam@hotmail.com
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D002384:Catalysis; D008027:Light; D013696:Temperature; D014025:Titanium / Q000737:chemistry*; D014414:Tungsten / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation*
D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium; D014414:Tungsten