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1.
Preparation and characterization of nitrogen-doped TiO2 photocatalyst in different acid environments
Ye Cong Ling Xiao Jinlong Zhang Feng Chen Masakazu Anpo 《Research on Chemical Intermediates》2006,32(8):717-724
Nitrogen-doped TiO2 powders were successfully prepared by a wet method, i.e., a micro-emulsion-hydrothermal method, in different acid environments.
Several characterization techniques, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible diffuse
reflectance spectra, were combined to determine the crystal phase, concentration and chemical states of the nitrogen doped
in TiO2. The high photocatalytic activity of the nitrogen-doped TiO2 was evaluated through the decomposition of rhodanmine B under visible light irradiation. It was suggested that the doped
nitrogen formed oxynitride (NO) and produced impurity states at higher above the valence band of TiO2. Therefore, the nitrogen doping could enhance the response of photocatalyst to the visible light and improve the photocatalytic
activity because of the narrowing of band gap of TiO2. 相似文献
2.
Atsunori Matsuda Tatsuo Matoda Yoshinori Kotani Toshihiro Kogure Masahiro Tatsumisago Tsutomu Minami 《Journal of Sol-Gel Science and Technology》2003,26(1-3):517-521
Anatase nanocrystals were precipitated mainly at the surface of the silica-titania gel films with hot water treatment, whereas the addition of poly(ethylene glycol) (PEG) in the films led to the dispersion of anatase nanocrystals in the whole of the films after the treatment. Both films with and without PEG showed high photocatalytic activities for acetaldehyde, NO
x
and stearic acid in the gas-solid system, and for methylene blue and potassium iodide in the liquid-solid system. The addition of PEG improved the photocatalytic activities of the resultant films due to the smaller anatase crystallites and the porous film structure. The residual silica under-layer of the superficially anatase-precipitated films is expected to act as a protective one for an organic polymer substrate against the photocatalytic degradation. 相似文献
3.
TiO2光催化反应及其在环境保护中的应用 总被引:8,自引:0,他引:8
本文简要介绍了TiO2光催化剂的作用机理,讨论了影响TiO2光催化效率的因素及解决途径,综述了光催化在环境保护中的最新应用。 相似文献
4.
The gas-phase photocatalytic oxidation of aniline on a new kind of porous nano-TiO2 composite films is investigated. The composite film was prepared on glass fiber with the water glass as binders and dilute
H2SO4 solution as solidifying reagent. The surface characters were observed by scanning electron microscope. The photocatalytic
degradation of aniline on the composite films was carried out in a TiO2/UV system. Some important factors affecting the photodegradation, such as the concentration of TiO2, the initial concentration of aniline, and the existing water vapor, are also studied. The product of photocatalytic oxidation
was detected by Fourier transform-Infrared. The partial intermediate products were absorbed on TiO2 surface, which resulted in catalyst deactivation. But when it was irradiated under UV illumination or solar irradiation for
some time, the catalyst could be reused without loss of catalytic activity.
Translated from the Journal of Wuhan University (Natural Science Edition), 2005, 51(2) (in Chinese) 相似文献
5.
Bitao Su Ke Wang Jie Bai Hongmei Mu Yongchun Tong Shixiong Min Shixiong She Ziqiang Lei 《Frontiers of Chemistry in China》2007,2(4):364-368
Fe3+-doped TiO2 composite nanoparticles with different doping amounts were successfully synthesized using sol-gel method and characterized
by X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultravioletvisible spectroscopy (UV-Vis) diffuse reflectance
spectra (DRS). The photocatalytic degradation of methylene blue was used as a model reaction to evaluate the photocatalytic
activity of Fe3+/TiO2 nanoparticles under visible light irradiation. The influence of doping amount of Fe3+ (ω: 0.00%–3.00%) on photocatalytic activities of TiO2 was investigated. Results show that the size of Fe3+/TiO2 particles decreases with the increase of the amount of Fe3+ and their absorption spectra are broaden and absorption intensities are also increased. Doping Fe3+ can control the conversion of TiO2 from anatase to rutile. The doping amount of Fe3+ remarkably affects the activity of the catalyst, and the optimum efficiency occurs at about the doping amount of 0.3%. The
appropriate doping of Fe3+ can markedly increase the catalytic activity of TiO2 under visible light irradiation.
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Translated from Journal of Northwest Normal University (Natural Science), 2006, 42(6): 55–56 [译自: 西北师范大学学报(自然科学版)] 相似文献
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8.
Mohammad Malakootian Hakimeh Mahdizadeh Abbas Dehdarirad 《Journal of Dispersion Science and Technology》2019,40(6):846-854
Ciprofloxacin is used in the treatment of bacterial infections. Because ciprofloxacin is not effectively degraded by biological processes, advanced oxidation processes such as photocatalytic ozonation are applied to remove this antibiotic from wastewater. The aim of this study was to investigate photocatalytic ozonation for the removal of ciprofloxacin from aquatic environments and optimization of the effective parameters of the process. For this purpose, ZnO nanoparticles were synthesized using the thermal method and immobilized on the surface of stones. The structural properties of the nanoparticles were determined by XRD, TEM, Photoluminescence (PL) and SEM. Experiments were carried out in a Plexiglas reactor supported with the continuous injection of ozone. The effective parameters for removal efficiency were reaction time, initial concentration of ciprofloxacin, pH, photocatalyst concentration and reaction kinetics. The highest ciprofloxacin removal efficiency occurred at the following optimal conditions: pH of 7, reaction time of 30?min, photocatalyst concentration of 3?g/L and initial ciprofloxacin concentration of 10?mg/L. Removal efficiency of 96% was obtained under these conditions. Linear kinetic models showed that the process followed pseudo-first order and Langmuir-Hinshelwood kinetics. This process had a high removal efficiency and suitable for removal of ciprofloxacin from aquatic environments.GRAPHICAL ABSTRACT 相似文献
9.
Andrzej Sobczynski 《Monatshefte für Chemie / Chemical Monthly》1992,123(3):211-216
Summary Silica-supported cadmium sulfide, highly active in hydrogen photogeneration from water-methanol-KOH solution, was prepared by sulfidation of Cd2+-impregnated SiO2. The samples consisted of colloidal-size hexagonal crystallites of CdS on amorphous SiO2. A blue shift of a light absorption edge was observed for the samples with lower CdS content.
Herstellung und photokatalytische Aktivität von feinen CdS-Pulvern auf SiO2
Zusammenfassung Es wurde Cadmiumsulfid auf Kieselgel durch Sulfidierung von Cd2+-imprägniertem SiO2 hergestellt, das eine außerordentliche Aktivität bei der Wasserstoff-Photogenerierung aus Wasser-Methanol-KOH-Lösungen zeigte. Der Katalysator bestand aus hexagonalen CdS-Kristalliten von kolloidalen Ausmaßen auf amorphem SiO2. An Proben mit geringerem CdS-Gehalt wurde eine Blauverschiebung der Lichtabsorption an der Absorptionskante beobachtet.相似文献
10.
Jun Suzuki Kenjiro Fujimoto Toshiyuki Mori Mamoru Watanabe Yoshio Hasegawa 《Journal of Sol-Gel Science and Technology》2000,19(1-3):775-778
The photocatalytic reduction of nitrogen monoxide (NO) with ethane on the hollandite type catalyst (K2Ga2Sn6O16KGSO) was investigated. Using a closed-gas circulating system equipped with a Q-MASS detector and in-situ diffuse reflectance FT-IR spectroscopy. The reactant gases of NO and 13C2H6 decreased with the increasing irradiation time. In contrast, the N2 yield increased proportionally to the conversion of 13C2H6. Nitrogen oxides such as N2O did not reach their detectable levels. The NO adsorbed on KGSO was found to change to its activated species by UV irradiation. The oxidized products of C2H6 such as CH3CHO increased in proportion to the reaction time. The present results strongly suggest that KGSO has remarkable photocatalytic activity for the reduction of NO with C2H6. 相似文献