Iron-doped titania nanoparticles exhibit a higher photocatalytic activity than pure TiO_2 for the degradation of nitrite. The optimum Fe-doped content in terms of activity is approximately 0.5%. The increase in photoa...Iron-doped titania nanoparticles exhibit a higher photocatalytic activity than pure TiO_2 for the degradation of nitrite. The optimum Fe-doped content in terms of activity is approximately 0.5%. The increase in photoactivity is probably due to the higher adsorption and the inhibition of electron-hole recombination. The photocatalytic oxidation reaction of nitrite over the Fe-doped TiO_2 catalyst follows zero-order kinetics, which is different from that over pure TiO_2. The reaction rate decreases linearly with the increase of the pH of the solution.展开更多
Fe^3＋ -doped nanometer TiO2 photocatalysts were prepared by sol-gel technique. TiO2 powders with different Fe^3＋ / Ti^4 ＋ molar ratios ranging from 0. 05% to 25% were synthesized by calcinating the gels in the temp...Fe^3＋ -doped nanometer TiO2 photocatalysts were prepared by sol-gel technique. TiO2 powders with different Fe^3＋ / Ti^4 ＋ molar ratios ranging from 0. 05% to 25% were synthesized by calcinating the gels in the temperature range of 200-600 ℃ . The effects of the content of iron ions and calcination temperature on the physical properties of the powders and their photocatalytic activities were examined by the photodecorapositon of methyl orange in sunlight. The results show that Fe dopant can decrease the temperature of nanatase-ratile transformation. The ideal photocatalytic property was achieved when the sample with an Fe^3＋ / Ti^4＋ ratio of 20 at% was calcined at about 300 ℃ for an hour, which is superior to that of commercial Degussa P-25. The optimum microstructure of the Fe-doped TiO2 for a high photocatalytic activity in sunlight is consisted of nanatase and ratile.展开更多
Rare earth ions La3＋ and Eu3＋ co-doped TiO2 photocatalyst （La-Eu/TiO2） was prepared by sol-gel method, and characterized by various techniques such as X-ray diffraction （XRD）, specific surface area and porosity ...Rare earth ions La3＋ and Eu3＋ co-doped TiO2 photocatalyst （La-Eu/TiO2） was prepared by sol-gel method, and characterized by various techniques such as X-ray diffraction （XRD）, specific surface area and porosity （BET and BJH）, scanning electron microscopy （SEM）, high resolution transmission electron microscopy （HRTEM）, UV-vis diffuse reflectance spectroscopy （DRS） and X-ray photoelectron spectroscopy （XPS）. The photocatalytic activity of the La-Eu/TiO2 was evaluated by the degradation of methylene blue （MB） under UV light irradiation. The catalyst had a relatively uniform particle diameter distribution in the range of 40–60 nm. When calcining at 600℃, the XRD patterns of La-Eu/TiO2 indicated the anatase phase, while the XPS patterns showed the Ti4＋, La3＋ and Eu3＋ ions existence. The DRS spectra showed red shift in the band-gap transition. The experimental results of MB degradation demonstrated that the photocatalytic activity of La-Eu/TiO2 was significantly enhanced due to better separation of photogenerated electron-hole pairs.展开更多
基金the National Natural Science Foundation of China.
文摘Iron-doped titania nanoparticles exhibit a higher photocatalytic activity than pure TiO_2 for the degradation of nitrite. The optimum Fe-doped content in terms of activity is approximately 0.5%. The increase in photoactivity is probably due to the higher adsorption and the inhibition of electron-hole recombination. The photocatalytic oxidation reaction of nitrite over the Fe-doped TiO_2 catalyst follows zero-order kinetics, which is different from that over pure TiO_2. The reaction rate decreases linearly with the increase of the pH of the solution.
基金Founded by the Science and Technology Foundation of AnhuiProvince (No.010301E2)
文摘Fe^3＋ -doped nanometer TiO2 photocatalysts were prepared by sol-gel technique. TiO2 powders with different Fe^3＋ / Ti^4 ＋ molar ratios ranging from 0. 05% to 25% were synthesized by calcinating the gels in the temperature range of 200-600 ℃ . The effects of the content of iron ions and calcination temperature on the physical properties of the powders and their photocatalytic activities were examined by the photodecorapositon of methyl orange in sunlight. The results show that Fe dopant can decrease the temperature of nanatase-ratile transformation. The ideal photocatalytic property was achieved when the sample with an Fe^3＋ / Ti^4＋ ratio of 20 at% was calcined at about 300 ℃ for an hour, which is superior to that of commercial Degussa P-25. The optimum microstructure of the Fe-doped TiO2 for a high photocatalytic activity in sunlight is consisted of nanatase and ratile.
基金Project supported by the "863 Program" of the Ministry of Science & Technology of China (2006AA06Z348)
文摘Rare earth ions La3＋ and Eu3＋ co-doped TiO2 photocatalyst （La-Eu/TiO2） was prepared by sol-gel method, and characterized by various techniques such as X-ray diffraction （XRD）, specific surface area and porosity （BET and BJH）, scanning electron microscopy （SEM）, high resolution transmission electron microscopy （HRTEM）, UV-vis diffuse reflectance spectroscopy （DRS） and X-ray photoelectron spectroscopy （XPS）. The photocatalytic activity of the La-Eu/TiO2 was evaluated by the degradation of methylene blue （MB） under UV light irradiation. The catalyst had a relatively uniform particle diameter distribution in the range of 40–60 nm. When calcining at 600℃, the XRD patterns of La-Eu/TiO2 indicated the anatase phase, while the XPS patterns showed the Ti4＋, La3＋ and Eu3＋ ions existence. The DRS spectra showed red shift in the band-gap transition. The experimental results of MB degradation demonstrated that the photocatalytic activity of La-Eu/TiO2 was significantly enhanced due to better separation of photogenerated electron-hole pairs.
