Direct modification with tungstophosphoric acid of mesoporous titania synthesized by urea-templated sol–gel reactions

Photochromism-based detection of volatile organic compounds by W-doped TiO2 nanofibers

“…When the samples were irradiated by 1.0 mW cm À2 UV light (commercial black-light lamp, low pressure mercury lamp with 365 nm filter) the color of all W-doped TiO 2 fibers became blue during photocatalytic process. And the photocatalytic rates increased with the percentage of tungsten doping, and this is the same results with the reported ones [4][5][6][7]. As reported [45], W 6+ can be easily reduced in W 5+ , it can be deduced that the photoexcited electrons in the conduction band of TiO 2 can be easily accepted by W 6+ , following the scheme TiO 2 ðe À cb Þ + W 6+ ?…”

“…This suggests that relatively more W species are present on the surface of the nanofibers film [41]. Tungsten (VI) oxides are more acidic than Ti (IV) oxides, so its presence on the surface increase the number of Brøsted acid sites [42] and it is a reason reported WO 3 -TiO 2 showed better photocatalytic abilities [4][5][6][7]. Fig.…”

“…Tungsten-doped TiO 2 systems showed improved photodegradation abilities of organic pollutants present in waters or air [4][5][6][7][8][9][10][11][12][13][14][15]. WO x species prevent the recombination of the electron-hole pairs as well as enhance the surface acidity of photocatalyst [4][5][6][7].…”

“…WO x species prevent the recombination of the electron-hole pairs as well as enhance the surface acidity of photocatalyst [4][5][6][7]. The W 6+ surface clusters work as electron traps to accept the electrons from the irradiated TiO 2 , which lead to the photochromism of W 6+ to W 5+ [8][9][10][11][12].…”

Synthesis of Polyoxometalate/TiO2Mesoporous Hybrid Materials and Their Photocatalytic Performance

“…[9] . 尽管溶胶-凝胶包合 法被认为能够比较牢固地负载 POM, 但由于制备过程 中体系 pH 变化等一些因素的影响, 易造成 POM 物种的 聚合和转化 [8,10,11] . Guo 等 [5,15] 首次采用缺位的 XW 11 …”