Nitrogen and/or carbon doped titania photocatalysts were prepared by a novel mechanochemical method. The prepared powders possessed two absorption edges around 400 and 540 nm wavelengths and showed excellent photocata...Nitrogen and/or carbon doped titania photocatalysts were prepared by a novel mechanochemical method. The prepared powders possessed two absorption edges around 400 and 540 nm wavelengths and showed excellent photocatalytic ability for nitrogen monoxide oxidation under visible light irradiation. Under the irradiation of visible light of wavelength >510 nm,37% of nitrogen monoxide could be continuously removed by the carbon and nitrogen co-doped titania prepared by planetary ball milling of P-25 titania–10% hexamethylenetetramine mixture followed by calcination in air at 400-C.展开更多
Yellowish nitrogen-doped titania was produced through sol-gel method in mild condition, with the elemental nitrogen derived from aqua ammonia. The titania catalysts were characterized using XRD, BET, TEM, XPS, and UV-...Yellowish nitrogen-doped titania was produced through sol-gel method in mild condition, with the elemental nitrogen derived from aqua ammonia. The titania catalysts were characterized using XRD, BET, TEM, XPS, and UV-Vis diffuse reflectance spectrophotometer, and their photocatalytic activities were evaluated under UV and visible light, respec tively. The XRD results showed that all titania catalysts were anatase. More significantly, the crystallite size of nitrogen-doped titania increased with an increase in N/Ti proportion, and the doping of nitrogen could extend the absorption shoulder into the visible-light region, thus it possessed a higher visible-light activity illustrated by decolorization of methyl orange （65.3%） under the irradiation of visible light, whereas pure titania showed little of such kind of visible light activity. The UV-light activity of nitrogen-doped titania catalysts was worse than that of pure titania and Degussa P25. In the range of N/Ti proportion of 4-10 mol%, the activity of nitrogen-doped titania weakened appreciably in the visible-light region as the N/Ti proportion increased, whereas a reverse relationship existed under the irradiation of UV light.展开更多
Magnetic TiO2/SiO2/NiFe204 composite photocatalytic particles with high crystalline TiO2 shell were synthesized via a mild solution route. The prepared composite particles were characterized with X-ray diffraction（XR...Magnetic TiO2/SiO2/NiFe204 composite photocatalytic particles with high crystalline TiO2 shell were synthesized via a mild solution route. The prepared composite particles were characterized with X-ray diffraction（XRD）, transmission electron microscopy（TEM）, high resolution transmission electron microscopy（HRTEM）, scanning electron microscopy（SEM）, ultraviolet-visible（UV-Vis） spectroscopy and vibrating sample magnetometer（VSM）. The results show that the obtained TiO2/SiO2/NiFe2O4 composite particles were composed of spherical nanoparticles, about 30 nm in diameter, with several NiFe/O4 fine particles about 20 nm in diameter as cores and silica as coatings and barrier layers between the magnetic cores and titania shells. The photocatalytic activity of the composite photocatalytic particles was also investigated for the degradation of Basic Violet 5BN（BV5） under UV irradiation. About 97% of original BV5 decomposed in 360 min in the presence of magnetic composite nanoparticles under UV light. The synthesized magnetic composite nanoparticles exhibited high photocatalytic efficiency that would find potential application to cleaning polluted water with the help of magnetic separation.展开更多
Ti-Ce, Ti-Si binary and Ti-Ce-Si ternary novel nanocomposite oxide photocatalysts were prepared with cheap inorganic salts TiCI4, Na2SiO3·9H2O and Ce（NO3）3·6H2O as precursors by supercritical fluid drying ...Ti-Ce, Ti-Si binary and Ti-Ce-Si ternary novel nanocomposite oxide photocatalysts were prepared with cheap inorganic salts TiCI4, Na2SiO3·9H2O and Ce（NO3）3·6H2O as precursors by supercritical fluid drying （SCFD） technology. The catalysts were characterized by means of XRD and TEM. The particle size of nanocomposite oxide photocatalysts synthesized by SCFD method is about 6 - 11 nm, which is smaller than those obtained by common drying method （CD）. The phase transformation from anatase to rutile was inhibited by SCFD technology. The peaks of SiO2 and CeO2 in XRD patterns indicate that a SiO2 amorphorous phase exists in all the samples and CeO2 is well dispersed on the surface of TiO2. The orthogonal test was designed to optimize the preparing conditions. It is found that ceria dop;.ng enhances the photocatalyric activity markedly, and the optimum doping of CeO2 is 0.1%. The thermal stability of photocatalyst can be improved ; the growth of particle-size and the decrease of surface area can be prohibited by doping of SlOe. Heat-treatment is a necessary factor to induce chemistry change of Ti-Si surface. The optimum heat-treating temperature is 600℃. A novel and efficient Ti-Ce-Si ternary nanocomposite was prepared by SCFI） method with strong thermal stability and high photoactivity in the photodegratation of phenol.展开更多
A mesoporous titania photocatalyst was prepared via calcining the solution of ionic liquid （1-methyl-3-butyl imidazolium bromide, [BMIM]Br） containing tetrabutyl titanate （TBT） and starch. The microstructure of th...A mesoporous titania photocatalyst was prepared via calcining the solution of ionic liquid （1-methyl-3-butyl imidazolium bromide, [BMIM]Br） containing tetrabutyl titanate （TBT） and starch. The microstructure of the prepared mesoporous titania was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and N2 adsorption/desorption isotherm. The results indicate that the resulting mesoporous titania has a grain size of about 13.9 nm, a special surface area of 106 m2/g, and a pore volume of 0.22 cm3/g, and the pore size can be adjusted by the concentration of starch in ionic liquid. The photocatalytic activity of mesoporous titania in the degradation of methyl orange solution was determined. The effect of the specific surface area of mesoporous titania on the photocatalytic activity was also studied. The prepared mesoporous titania exhibits a high catalytic activity.展开更多
基金A Grant-in-Aid for the COE project (Giant Molecules and Complex Systems), a Grant-in-Aid for Science Research (No.14750660) by Ministry of Education, Culture, Sports, Science and Technology, Japan, the JFE 21st Century Foundation and the Steel Industry for the Advancement of Environmental Protection Technology Foundation, Japan
文摘Nitrogen and/or carbon doped titania photocatalysts were prepared by a novel mechanochemical method. The prepared powders possessed two absorption edges around 400 and 540 nm wavelengths and showed excellent photocatalytic ability for nitrogen monoxide oxidation under visible light irradiation. Under the irradiation of visible light of wavelength >510 nm,37% of nitrogen monoxide could be continuously removed by the carbon and nitrogen co-doped titania prepared by planetary ball milling of P-25 titania–10% hexamethylenetetramine mixture followed by calcination in air at 400-C.
基金the Open Fund of the Key Laboratory of Enhanced Heat and Energy Conservation of Chinese Ministry of Education, South China University of Technology.
文摘Yellowish nitrogen-doped titania was produced through sol-gel method in mild condition, with the elemental nitrogen derived from aqua ammonia. The titania catalysts were characterized using XRD, BET, TEM, XPS, and UV-Vis diffuse reflectance spectrophotometer, and their photocatalytic activities were evaluated under UV and visible light, respec tively. The XRD results showed that all titania catalysts were anatase. More significantly, the crystallite size of nitrogen-doped titania increased with an increase in N/Ti proportion, and the doping of nitrogen could extend the absorption shoulder into the visible-light region, thus it possessed a higher visible-light activity illustrated by decolorization of methyl orange （65.3%） under the irradiation of visible light, whereas pure titania showed little of such kind of visible light activity. The UV-light activity of nitrogen-doped titania catalysts was worse than that of pure titania and Degussa P25. In the range of N/Ti proportion of 4-10 mol%, the activity of nitrogen-doped titania weakened appreciably in the visible-light region as the N/Ti proportion increased, whereas a reverse relationship existed under the irradiation of UV light.
基金Supported by the National Natural Science Foundation of China(No.20803089)the Fund of Science and Technology of Shanxi Province for Young Scholars,China(Nos.2007021012,2008021010)
文摘Magnetic TiO2/SiO2/NiFe204 composite photocatalytic particles with high crystalline TiO2 shell were synthesized via a mild solution route. The prepared composite particles were characterized with X-ray diffraction（XRD）, transmission electron microscopy（TEM）, high resolution transmission electron microscopy（HRTEM）, scanning electron microscopy（SEM）, ultraviolet-visible（UV-Vis） spectroscopy and vibrating sample magnetometer（VSM）. The results show that the obtained TiO2/SiO2/NiFe2O4 composite particles were composed of spherical nanoparticles, about 30 nm in diameter, with several NiFe/O4 fine particles about 20 nm in diameter as cores and silica as coatings and barrier layers between the magnetic cores and titania shells. The photocatalytic activity of the composite photocatalytic particles was also investigated for the degradation of Basic Violet 5BN（BV5） under UV irradiation. About 97% of original BV5 decomposed in 360 min in the presence of magnetic composite nanoparticles under UV light. The synthesized magnetic composite nanoparticles exhibited high photocatalytic efficiency that would find potential application to cleaning polluted water with the help of magnetic separation.
文摘Ti-Ce, Ti-Si binary and Ti-Ce-Si ternary novel nanocomposite oxide photocatalysts were prepared with cheap inorganic salts TiCI4, Na2SiO3·9H2O and Ce（NO3）3·6H2O as precursors by supercritical fluid drying （SCFD） technology. The catalysts were characterized by means of XRD and TEM. The particle size of nanocomposite oxide photocatalysts synthesized by SCFD method is about 6 - 11 nm, which is smaller than those obtained by common drying method （CD）. The phase transformation from anatase to rutile was inhibited by SCFD technology. The peaks of SiO2 and CeO2 in XRD patterns indicate that a SiO2 amorphorous phase exists in all the samples and CeO2 is well dispersed on the surface of TiO2. The orthogonal test was designed to optimize the preparing conditions. It is found that ceria dop;.ng enhances the photocatalyric activity markedly, and the optimum doping of CeO2 is 0.1%. The thermal stability of photocatalyst can be improved ; the growth of particle-size and the decrease of surface area can be prohibited by doping of SlOe. Heat-treatment is a necessary factor to induce chemistry change of Ti-Si surface. The optimum heat-treating temperature is 600℃. A novel and efficient Ti-Ce-Si ternary nanocomposite was prepared by SCFI） method with strong thermal stability and high photoactivity in the photodegratation of phenol.
基金supported by the Natural Sci-ence Foundation of Guangdong Province, China (No. 7301526) the Youth Science Foundation of Hanshan Normal University (No. 413811)
文摘A mesoporous titania photocatalyst was prepared via calcining the solution of ionic liquid （1-methyl-3-butyl imidazolium bromide, [BMIM]Br） containing tetrabutyl titanate （TBT） and starch. The microstructure of the prepared mesoporous titania was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and N2 adsorption/desorption isotherm. The results indicate that the resulting mesoporous titania has a grain size of about 13.9 nm, a special surface area of 106 m2/g, and a pore volume of 0.22 cm3/g, and the pore size can be adjusted by the concentration of starch in ionic liquid. The photocatalytic activity of mesoporous titania in the degradation of methyl orange solution was determined. The effect of the specific surface area of mesoporous titania on the photocatalytic activity was also studied. The prepared mesoporous titania exhibits a high catalytic activity.
