以钛酸四丁酯为钛源, 分别使用微波加热法和水热法制备Ag改性的TiO2, 采用X射线衍射(XRD)、X射线荧光探针(XRF)、紫外可见漫反射(UV-Vis)和扫描电镜(SEM)对其进行表征. 以气相甲苯为降解对象, 分别在紫外和可见光辐照下, 对样品进行光催化活性试验. 结果表明:与水热法比较, 微波加热法更有利于Ag对TiO2微观结构的改性, 所制备的Ag改性TiO2包含了锐钛矿、金红石和板钛矿三种晶相, 其粒径更小(16.4nm)、孔道结构更丰富、团聚体更小(80~200nm)、带隙能更低(2.87eV), 表现出对气相甲苯更有效的紫外光和可见光降解能力.
Using Ti(OBu)4 as titanium source, Agmodified TiO2 was prepared by the microwave heating method and the hydrothermal ethod, respectively, and was characterized by Xray diffraction (XRD), Xray fluorescence (XRF), ultravioletvisible diffuse reflectance spectroscope (UV-Vis) and scanning electron microscope (SEM). The photocatalytic activity of the samples was tested in the degradation of gaseous toluene under UV and visible light irradiation, respectively. The results showed that the presence of Ag promoted the phase transformation of TiO2 from anatase to other phases. Compared with the hydrothermal method, the microwave heating method had more positive effect on the formation of Agmodified TiO2 with smaller crystallite size (16.4nm) and aggregate (80-200nm), more phases structure (anatase, rutile and brookite), richer channel structure, and lower band gap energy (2.87eV). Furthermore, Agmodified TiO2 prepared by the microwave heating method exhibited a better photocatalytic activity in the degradation of toluene under UV or visible light irradiation.
[1]Hoffman M R, Martin S T, Choi W Y, et al. Environmental applications of semiconductor photocatalysis. Chemical Reviews, 1995, 95(1): 69-96.
[2]Sun B, Reddy E P, Smirniotis P G. Visible light Cr(Ⅳ) reduction and organic chemical oxidation by TiO2 photocatalysis. Environmental Science & Technology, 2005, 39(16): 6251-6259.
[3]Wu Z B, Dong F, Zhao W R, et al. Visible light induced electron transfer process over nitrogen doped TiO2 nanocrystals prepared by oxidation of titanium nitride. Journal of Hazardous Materials, 2008, 157(1): 57-63.
[4]Rengaraj S, Li X Z. Enhanced photocatalytic activity of TiO2 by doping with Ag for degradation of 2,4,6trichlorophenol in aqueous suspension. Journal of Molecular Catalysis A: Chemical, 2006, 243(1): 60-67.
[5]Tada H, Ishida T, Takao A, et al. Drastic enhancement of TiO2photocatalyzed reduction of nitrobenzene by loading Ag clusters. Langmuir, 2004, 20(19): 7898-7900.
[6]Miao L, Ina Y, Tanemura S, et al. Fabrication and photochromic study of titanate nanotubes loaded with silver nanoparticles. Surface Science, 2007, 601(13): 2792-2799.
[7]He X, Zhao X J, Liu B S. The synthesis and kinetic growth of anisotropic silver particles loaded on TiO2 surface by photoelectrochemical reduction method. Applied Surface Science, 2008, 254(6): 1705-1709.
[8]Rodriguez J, Gomez M, Lindquist S E, et al. Photoelectrocatalytic degradation of 4chlorophenol over sputter deposited Ti oxide films. Thin Solid Films, 2000, 360(1/2): 250-255.
[9]Zhang J M, Wei X M, Xin H. Energy analysis for (111) twist grain boundary in noble metals. Applied Surface Science, 2005, 243(1-4): 1-6.
[10]Bykov Y V, Rybakov K I, Semenov V E. Hightemperature microwave processing of material. Journal of Physics D: Applied Physics, 2001, 34(13): 55-75.
[11]Yamamoto T, Wada Y, Yin H B, et al. Microwavedriven polyol method for preparation of TiO2 nanocrystallites. Chemistry Letters, 2002, 31(10): 964-965.
[12]Khan M A, Woo S I, Yang O B. Hydrothermally stabilized Fe(Ⅲ) doped titania active under visible light for water splitting reaction. International Journal of Hydrogen Energy, 2008, 33(20): 53455351.
[13]Yu J G, Xiong J F, Cheng B, et al. Fabrication and characterization of AgTiO2 multiphase nanocomposite thin films with enhanced photocatalytic activity. Applied Catalysis B: Environmental, 2005, 60(3/4): 211-221.
[14]Baghurst D R, Mingos D M P. Application of microwaveheating techniques for the synthesis of solidstate inorganiccompounds. Journal of the Chemical SocietyChemical Communications, 1988(12): 829-830.
[15]Oman D M, Dugan K M, Killian J L, et al. Device performance characterization and junction mechanisms in CdTe/CdS solar cells. Solar Energy Materials and Solar Cells, 1999, 58(4): 361-373.
[16]Rao K V S, Lavrine B, Boule P. Influence of metallic species on TiO2 for the photocatalytic degradation of dyes and dye intermediates. Journal of Photochemistry and Photobiology A: Chemistry, 2003, 154(2/3): 189-193.
[17]Hamal D B, Klabunde K J. Synthesis, characterization, and visible light activity of new nanoparticle photocatalysts based on silver, carbon, and sulfur-doped TiO2. Journal of Colloid and Interface Science, 2007, 311(2): 514-522.