National Center of Excellence for Environmental and Hazardous Waste Management, Chulalongkorn University, Bangkok 10130, Thailand.
Water Sci Technol. 2010;62(9):2128-33. doi: 10.2166/wst.2010.410.
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.
本研究旨在通过改变溶胶-凝胶条件和掺杂钨来拓展 TiO(2) 的活性，使其能够响应可见光。煅烧温度、酸类型和升温速率的最佳条件分别为 200°C、HNO(3)和 1°C/min。在这些条件下合成的未掺杂 TiO(2)可以显著吸收可见光，而商业 Degussa P-25 则不能。吸收度随着波长从 400nm 增加到 700nm 而依次降低。在 2-W 蓝光照射 6 小时内，0.1mM 的 2-氯苯酚有 23%被去除。XRD 结果表明晶体为锐钛矿相。当掺杂钨时，TiO(2)的可见光吸收性能变得更好。在最佳的 W/TiO(2)摩尔比为 0.5%时，0.1mM 的 2-氯苯酚的降解率增加到 53%，表明光催化活性更高。结晶和非晶态 TiO(2)都可以在可见光区域表现出光催化活性。
