Nanostructured metal oxides synthesized by hard template method for gas sensing applications

Abstract In order to increase the surface area, mesoporous oxides have been synthesized. In this work, we have used mesoporous silica SBA-15 and KIT-6 as a template for the synthesis of different semiconductor oxides: CeO 2 and WO 3 . These materials show a small particle size, about 5–10 nm, and a high surface area. As required increase the sensitivity when used for gas sensing applications. XRD and HRTEM studies reveal that the silica host has been completely removed; therefore, the nanowires constitute a self-supported superlattice.

[1]  Fredrickson,et al.  Triblock copolymer syntheses of mesoporous silica with periodic 50 to 300 angstrom pores , 1998, Science.

[2]  Meilin Liu,et al.  Distributions of noble metal Pd and Pt in mesoporous silica , 2002 .

[3]  Toshio Suzuki,et al.  RAMAN SCATTERING AND LATTICE DEFECTS IN NANOCRYSTALLINE CEO2 THIN FILMS , 2002 .

[4]  Feng Gao,et al.  Room-temperature synthesis in acidic media of large-pore three-dimensional bicontinuous mesoporous silica with Ia3d symmetry. , 2002, Angewandte Chemie.

[5]  Makoto Egashira,et al.  Basic Aspects and Challenges of Semiconductor Gas Sensors , 1999 .

[6]  F. Kleitz,et al.  Cubic Ia3d large mesoporous silica: synthesis and replication to platinum nanowires, carbon nanorods and carbon nanotubes. , 2003, Chemical communications.

[7]  M. Hon,et al.  Sensitivity properties of a novel NO2 gas sensor based on mesoporous WO3 thin film , 2003 .

[8]  R. Ryoo,et al.  Synthesis of thermally stable mesoporous cerium oxide with nanocrystalline frameworks using mesoporous silica templates. , 2003, Chemical communications.

[9]  J. B. Higgins,et al.  A new family of mesoporous molecular sieves prepared with liquid crystal templates , 1992 .

[10]  Avelino Corma,et al.  Hierarchically mesostructured doped CeO2 with potential for solar-cell use , 2004, Nature materials.

[11]  Fred H. Pollak,et al.  Raman scattering in alloy semiconductors: Spatial correlation model , 1984 .

[12]  Weber,et al.  Raman study of CeO2: Second-order scattering, lattice dynamics, and particle-size effects. , 1993, Physical review. B, Condensed matter.

[13]  D. Zhao,et al.  One-step nanocasting synthesis of highly ordered single crystalline indium oxide nanowire arrays from mesostructured frameworks. , 2003, Journal of the American Chemical Society.

[14]  D. Zhao,et al.  Recent advances in the synthesis of non-siliceous mesoporous materials , 2003 .

[15]  L. Ley,et al.  The one phonon Raman spectrum in microcrystalline silicon , 1981 .

[16]  G. Lucazeau,et al.  Crystallite Nanosize Effect on the Structural Transitions of WO3 Studied by Raman Spectroscopy , 2002 .

[17]  Claudio Vinegoni,et al.  X-ray diffraction, extended x-ray absorption fine structure and Raman spectroscopy studies of WO3 powders and (1−x)WO3−y⋅xReO2 mixtures , 1998 .

[18]  D. Blom,et al.  Synthesis of Ordered Metallic Nanowires inside Ordered Mesoporous Materials through Electroless Deposition , 2002 .

[19]  A. G. S. Filho,et al.  Phase transition in WO3 microcrystals obtained by sintering process , 2001 .

[20]  S. Kawi,et al.  Synthesis, characterization and sensing application of novel semiconductor oxides. , 1998, Talanta.

[21]  Xuan Zhang,et al.  Crystalline WO3 nanowires synthesized by templating method , 2003 .

[22]  A. Anderson.  Raman Study of Ceramic Tungsten Trioxide at Low Temperatures , 1976 .

[23]  Bozhi Tian,et al.  Facile synthesis and characterization of novel mesoporous and mesorelief oxides with gyroidal structures. , 2004, Journal of the American Chemical Society.

[24]  Chang Hyun Ko,et al.  Disordered molecular sieve with branched mesoporous channel network , 1996 .

[25]  N. Sugimoto,et al.  Novel templating synthesis of necklace-shaped mono- and bimetallic nanowires in hybrid organic-inorganic mesoporous material. , 2001, Journal of the American Chemical Society.

[26]  V. Freire,et al.  Coexistence of triclinic and monoclinic phases in WO3 ceramics , 2000 .

[27]  G. Stucky,et al.  Preparation of Noble Metal Nanowires Using Hexagonal Mesoporous Silica SBA-15 , 2000 .

[28]  Keiichi Yamamoto,et al.  Raman studies of phase transitions in gas-evaporated WO3 microcrystals , 1990 .

[29]  Sibudjing Kawi,et al.  High-surface-area SnO2 : a novel semiconductor-oxide gas sensor , 1998 .