A new anatase/SiO<sub>2</sub> nanocomposite was synthesized by sol-gel method at room temperature using titanium tetrachloride and tetraethylorthosilicate as raw materials. Characterization of the product was carried out by means of X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) specific surface areas, Thermogravimetry analysis (TGA), Fourier transform infrared (FT-IR), and UV-vis absorption spectroscopy. Thermal phase transformation studies of composite were carried out up to 1100°C which showed the establishment of anatase TiO<sub>2</sub> phase. The presence of some tetrahedral coordination of TiO<sub>2</sub> species in SiO<sub>2</sub> matrix was confirmed by UV-Vis study. The produced TiO<sub>2</sub>/SiO<sub>2</sub> nanocomposite has good photocatalytic properties due to its anatase phase, existence of tetrahedral coordination of TiO<sub>2</sub> in the SiO<sub>2</sub> matrix and very large surface area. Furthermore, the synthesized anatase/SiO<sub>2</sub> shows significant adsorption ability towards Congo Red (CR) azo dye in comparison with the pure commercial TiO<sub>2</sub> which is known as Degussa, P25.
KeywordsTiO<sub>2</sub>/SiO<sub>2</sub>NanocompositesSol-Gel PreparationPhotocatalystCongo Red
C. M. Visinescu, R. Sanjines, F. Levy, V. Marcuc and V. I. Parvulescu, “Tantalum Doped Titania Photocatalysts: Preparation by dc Reactive Sputtering and Catalytic Behavior,” Journal of Photochemistry and Photobiology A: Chemistry, Vol. 174, No. 2, August 2005, pp. 106-110. doi:10.1016/j.jphotochem.2005.03.017
M. H. Habibi, S. Tangestaninejad and B. Yadollahi, “Photocatalytic Mineralization of Mercaptans as Environmental Pollutants in Aquatic System Using TiO2 Suspension,” Applied Catalysis. B: Environment, Vol. 33, No. 1, September 2001, pp. 57-61. doi:10.1016/S0926-3373(01)00158-8
D. G. Shchukin and D. V. Sviridov, “Photocatalytic Processes in Spatially Confined Micro- and Nanoreactors,” Journal of Photochemistry and Photobiology A: Chemistry Review, Vol. 7, 2006, pp. 23-39.
R. Zhang, L. Gao and Q. Zhang, “Photodegradation of Surfactants on the Nanosized TiO2 Prepared by Hydrolysis of the Alkoxide Titanium,” Chemosphere, Vol. 54, No. 3, January 2004, pp. 405-411. doi:10.1016/S0045-6535(03)00588-5
K. Patterson, B. W. Lykins, J. C. Ireland, S. D. Richardson, A. D. Thruston and T. W. Collett, “Identification of TiO2/UV Disinfection Byproducts in Drinking Water,” Environmental Science and Technology, Vol. 30, No. 11, 1996, pp. 3327-3334. doi:10.1021/es960142m
P. S. Awati, S. V. Awate, P. P. Shah and V. Ramaswamy, “Photocatalytic Decomposition of Methylene Blue Using Nanocrystalline Anatase Titania Prepared by Ultrasonic Technique,” Catalysis. Communications, Vol. 4, No. 8, August 2003, pp. 393-400. doi:10.1016/S1566-7367(03)00092-X
D. Beydoun, R. Amal, G. Low and S. McEvoy, “Role of Nanoparticles in Photocatalysis,” Journal of Nanoparticle Research, Vol. 1, 1999, pp. 439-458. doi:10.1023/A:1010044830871
M. R. Prairie, L. R. Evans, B. M. Stange and S. L. Marlinez, “An Investigation of TiO2 Photocatalysis for the Treatment of Water Contaminated with Metals and Organic Chemicals,” Environmental Science and Technology, Vol. 9, 1993, p. 27.
P. Chenga, C. Denga, M. Gub and A. X. Dai, “Effect of Urea on the Photoactivity of Titania Powder Prepared by Sol-Gel Method,” Materials Chemistry and Physics, Vol. 107, No. 1, January 2008, pp. 77-81. doi:10.1016/j.matchemphys.2007.06.051
G. Calleja, D. P. Serrano, R. Sanz and P. Pizarro, “Mesostructured SiO2-Doped TiO2 with Enhanced Thermal Stability Prepared by a Soft-Templating Sol-Gel Route,” Microporous and Mesopororous Materials, Vol. 111, 2008, p. 429.
C. Garzella, E. Comini, E. Bontempil, L. E. Deperol, C. Frigeri and G. Sberveglieri, “Nanostructured TiO2 and W: TiO2 Thin Films by a Novel Sol-Gel Processing for Alcohol Sensing Devices,” Materials Research Society Symposium Proceedings, Vol. 638, 2001, p. 111.
Z. Wang, U. Helmersson and P. Kall, “Optical Properties of Anatase TiO2 Thin Films Prepared by Aqueous Sol-Gel Process at Low Temperature.” Thin Solid Films, Vol. 405, No. 1-2, February 2002, pp. 50-54. doi:10.1016/S0040-6090(01)01767-9
T. Ivanova, A. Harizanova and M. Surtchev, “Formation and Investigation of Sol-Gel TiO2-V2O5 System,” Materials Letters, Vol. 55, 2002, pp. 327-333.
S. Dohshi, M. Takeuchi and M. Anpo, “Effect of the Local Structure of Ti-Oxide Species on the Photocatalytic Reactivity and Photo-Induced Super-Hydrophilic Properties of Ti/Si and Ti/B Binary Oxide Thin Films,” Catalysis Today, Vol. 85, No. 2-4, October 2003, pp. 199-205. doi:10.1016/S0920-5861(03)00387-0
R. R. Gon?alves, Y. Messaddeq, M. Atik and S. J. L. Ribeiro, “Optical Properties of ZrO2, SiO2 and TiO2-SiO2 Xero gels and Coatings Doped with Eu3+ and Eu2+,” Journal of Material Research, Vol. 2, No. 1, January 1999, pp. 11-15.
T. Nishide, M. Sato and H. Hara, “Crystal Structure and Optical Property of TiO2 Gels and Films Prepared from Ti-Edta Complexes as Titania Precursors,” Journal of Material Science, Vol. 35, 2000, pp. 465-469.
S. Cabrera, J. El Haskouri, A. Beltra’n-Porter, D. Beltra’n-Porter, M. D. Marcos and P. Amoro’s, “Enhanced Surface Area in Thermally Stable Pure Mesoporous TiO2,” Solid State Science, Vol. 2, No. 5, September 2000, pp. 513-518. doi:10.1016/S1293-2558(00)00057-1
L. Zhou, S. Yan, B. Tian, J. Zhang and M. Anpo, “Preparation of TiO2-SiO2 Film with High Photocatalytic Activity on PET Substrate,” Materials Letters, Vol. 60, No. 3, February 2006, pp. 396-402. doi:10.1016/j.matlet.2005.08.065
A. L. Patterson, “The Sherrer Formula for X-Ray Particle Size Determination,” Physical Review, Vol. 56, 1939, pp. 978-983. doi:10.1103/PhysRev.56.978
Y. Gao, Y. Masuda, Z. Peng, T. Yonezawa and K. Koumoto, “Light-Excited Super Hydrophilicity of Amorphous TiO2 Thin Films Deposited in an Aqueous Peroxotitanate Solution,” Journal of Material Chemistry, Vol. 13, 2003, pp. 608-613. doi:10.1039/b208105a
G. Calleja, D. P. Serrano, R. Sanz, P. Pizarro and A. Garc?′a, “Study on the Synthesis of High-Surface-Area Mesoporous TiO2 in the Presence of Nonionic Surfactants,” Indian Engineering Chemical Research, Vol. 43, No. 10, 2004, pp. 2485-2492. doi:10.1021/ie030646a
S. J. Kalita, S. Qiu and S. Verma, “A Quantitative Study of the Calcination and Sintering of Nanocrystalline Titanium Dioxide and Its Flexural Strength Properties,” Materials Chemistry and Physics, Vol. 109, No. 2-3, June 2008, pp. 392-398. doi:10.1016/j.matchemphys.2007.12.031
S. J. Kim, S. D. Park, C. K. Rhee, W. W. Kim and S. Park, “Photocatalytic Characteristics of Homogeneously precipitated TiO2 Nano-Sized Powders,” Scripta Materialia, Vo. 44, 2001, pp. 1229-1233. doi:10.1016/S1359-6462(01)00854-5
J. Aguado, M. Grieken, J. Lopez-Munoz and J. Marugan, “A Comprehensive Study of the Synthesis, Characterization and Activity of TiO2 and Mixed TiO2/SiO2,” .Applied Catalysis A: General, Vol. 312, September 2006, pp. 202-210. doi:10.1016/j.apcata.2006.07.003
K. Kabra, R. Chaudhary and R. L. Sawhney, “Treatment of Hazardous Organic and Inorganic Compounds through Aqueous-Phase,” Photocatalysis: A Review Indian Engineering Chemical Research, Vol. 43, 2004, pp. 7683-7696.
M. Machida, K. Norimoto, T. Watanabe, K. Hashimoto and A. Fujishima, “The Effect of SiO2 Addition in Super-Hydophylic Property of TiO2 Photocatalyst,” Journal of Material Science, Vol. 34, 1999, pp. 2569-2574. doi:10.1023/A:1004644514653
M. N. Kamalasanan and S. Chandra, “Sol-Gel Synthesis of ZnO Thin Films,” Thin Solid Films, Vol. 288, No. 1-2, November 1996, pp. 112-118. doi:10.1016/S0040-6090(96)08864-5
P. Wang, S. M. Zakeeruddin, I. Exnarb and M Gr?tzel, “High Efficiency Dye-Sensitized Nanocrystalline Solar cells Based on Ionic Liquid Polymer Gel Electrolyte,” Chemical Communications, Vol. 111, 2002, pp. 2972-2973. doi:10.1039/b209322g
M. Zribi, M. Kanzari and B. Rezig, “Structural, Morphological and Optical Properties of Thermal Annealed TiO Thin Films,” Thin Solid Films, Vol. 516, 2008, pp. 1476-1482. doi:10.1016/j.tsf.2007.07.195
H. Yamashita, Y. Ichihashi, M. Harada, M. Stewart, A. Fox and M. Anpo, “Photocatalytic Degradation of 1-Octanol on Anchored Titanium Oxide and on TiO2 Powder Catalysts,” Journal of Catalysis, Vol. 158, 1996, pp. 97-103. doi:10.1006/jcat.1996.0010