The Experts below are selected from a list of 16131 Experts worldwide ranked by ideXlab platform
Young Hwa Jung - One of the best experts on this subject based on the ideXlab platform.
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solvothermal synthesis of Tungsten Oxide nanorod nanowire nanosheet
Journal of the American Ceramic Society, 2005Co-Authors: Hong Goo Choi, Young Hwa JungAbstract:A simple process enables to synthesize Tungsten Oxide with various nanomorphologies, i.e. nanorods, nanowires, and nanosheets. The Tungsten hexachloride (WCl6) was used as a raw material and the Tungsten Oxide nanoparticles were obtained by solvothermal treatment with solvents, i.e., ethanol, mixed solvent (ethanol1water), and water, at 2001C for 10 h. The various crystalline phases of Tungsten Oxide, such as monoclinic W 18O49 nanorods, hexagonal WO3 platelets, and monoclinic WO3 nanosheets, were synthesized by simply changing the composition of the solvent. The oxygen, which was contained in water, played an important role in the final Tungsten Oxide phase. Especially, W18O49 nanorods grew to nanowires as the concentration of WCl6 was decreased. Using this simple process, it will be possible to control the crystalline phase and morphologies of nanostructured Tungsten Oxide system.
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Solvothermal Synthesis of Tungsten Oxide Nanorod/Nanowire/Nanosheet
Journal of the American Ceramic Society, 2005Co-Authors: Hong Goo Choi, Young Hwa JungAbstract:A simple process enables to synthesize Tungsten Oxide with various nanomorphologies, i.e. nanorods, nanowires, and nanosheets. The Tungsten hexachloride (WCl6) was used as a raw material and the Tungsten Oxide nanoparticles were obtained by solvothermal treatment with solvents, i.e., ethanol, mixed solvent (ethanol1water), and water, at 2001C for 10 h. The various crystalline phases of Tungsten Oxide, such as monoclinic W 18O49 nanorods, hexagonal WO3 platelets, and monoclinic WO3 nanosheets, were synthesized by simply changing the composition of the solvent. The oxygen, which was contained in water, played an important role in the final Tungsten Oxide phase. Especially, W18O49 nanorods grew to nanowires as the concentration of WCl6 was decreased. Using this simple process, it will be possible to control the crystalline phase and morphologies of nanostructured Tungsten Oxide system.
Hong Goo Choi - One of the best experts on this subject based on the ideXlab platform.
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solvothermal synthesis of Tungsten Oxide nanorod nanowire nanosheet
Journal of the American Ceramic Society, 2005Co-Authors: Hong Goo Choi, Young Hwa JungAbstract:A simple process enables to synthesize Tungsten Oxide with various nanomorphologies, i.e. nanorods, nanowires, and nanosheets. The Tungsten hexachloride (WCl6) was used as a raw material and the Tungsten Oxide nanoparticles were obtained by solvothermal treatment with solvents, i.e., ethanol, mixed solvent (ethanol1water), and water, at 2001C for 10 h. The various crystalline phases of Tungsten Oxide, such as monoclinic W 18O49 nanorods, hexagonal WO3 platelets, and monoclinic WO3 nanosheets, were synthesized by simply changing the composition of the solvent. The oxygen, which was contained in water, played an important role in the final Tungsten Oxide phase. Especially, W18O49 nanorods grew to nanowires as the concentration of WCl6 was decreased. Using this simple process, it will be possible to control the crystalline phase and morphologies of nanostructured Tungsten Oxide system.
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Solvothermal Synthesis of Tungsten Oxide Nanorod/Nanowire/Nanosheet
Journal of the American Ceramic Society, 2005Co-Authors: Hong Goo Choi, Young Hwa JungAbstract:A simple process enables to synthesize Tungsten Oxide with various nanomorphologies, i.e. nanorods, nanowires, and nanosheets. The Tungsten hexachloride (WCl6) was used as a raw material and the Tungsten Oxide nanoparticles were obtained by solvothermal treatment with solvents, i.e., ethanol, mixed solvent (ethanol1water), and water, at 2001C for 10 h. The various crystalline phases of Tungsten Oxide, such as monoclinic W 18O49 nanorods, hexagonal WO3 platelets, and monoclinic WO3 nanosheets, were synthesized by simply changing the composition of the solvent. The oxygen, which was contained in water, played an important role in the final Tungsten Oxide phase. Especially, W18O49 nanorods grew to nanowires as the concentration of WCl6 was decreased. Using this simple process, it will be possible to control the crystalline phase and morphologies of nanostructured Tungsten Oxide system.
Vo Van Truong - One of the best experts on this subject based on the ideXlab platform.
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Electrochromic properties of sol-gel synthesized macroporous Tungsten Oxide films doped with gold nanoparticles
Journal of the Electrochemical Society, 2014Co-Authors: Mohammed Alsawafta, Y.m. Golestani, T. Phonemac, Victor Stancovski, Simona Badilescu, Vo Van TruongAbstract:Macroporous Tungsten Oxide thin films were prepared by using a polystyrene microsphere template and the peroxitungstic acid precursor. Gold nanoparticles were introduced into the Tungsten Oxide film by two different methods, either in the polystyrene template, through a self-assembly process, or they were cast on the surface of the annealed film. Raman imaging experiments showed an enhancement effect of the intensity of the major Tungsten Oxide bands by the gold nanoislands. The electrochromic properties of gold-doped macroporous Tungsten Oxide are described and compared to those of the standard porous sol-gel film. The films with gold nanoparticles on the surface of the Tungsten Oxide film were found to have better electrochromic properties than the standard sol-gel Tungsten Oxide films and the ones doped with gold in the polystyrene template. The diffusion coefficients of protons in the gold-doped Tungsten Oxide films were determined from both Cyclic Voltammetry (CV) and Electrical Impedance Spectroscopy (EIS) measurements. The results indicate a faster diffusion of the proton in the porous film, compared with a compact Tungsten Oxide film. The model that evolves from the EIS data, involves fast charge transfer rates at the electrolyte/Tungsten Oxide film interface. The results demonstrated an enhancement of the coloration efficiency of the macroporous Tungsten Oxide films with Au nanoparticles on the surface of the film. The possible involvement of plasmon resonance of Au nanoparticles in the electrochromic process is discussed. © 2014 The Electrochemical Society. All rights reserved.
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Study of lithium intercalation into Tungsten Oxide films prepared by different methods
Thin Solid Films, 1994Co-Authors: Simona Badilescu, P. V. Ashrit, N. Minh-ha, G. Bader, Fernand E. Girouard, Vo Van TruongAbstract:Abstract The interaction of lithium atoms into amorphous Tungsten Oxide films deposited by thermal evaporation, sputtering and sol-gel synthesis is studied spectroscopically. The mechanism of insertion of lithium into the film depends on the amount and the bonding state of water to the Tungsten Oxide network. Thermally evaporated Tungsten Oxide film contains water bonded chemically in the form of a hydrogen Tungsten bronze which facilitates the accommodation of a high number of lithium atoms. In the sputtered film, water is physisorbed and the lithiation is incomplete. Tungsten Oxide films prepared by sol-gel synthesis have structural water molecules directly involved in the lithiation process. The formation of lithium tungstate independent of the preparation method is demonstrated.
D M Phase - One of the best experts on this subject based on the ideXlab platform.
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Nanostructured Tungsten Oxide thin films by the reactive pulsed laser deposition technique
Applied Physics A, 2008Co-Authors: K. J. Lethy, V. Sathe, D. Beena, R. Vinod Kumar, Vinitha Ganesan, V. P. Mahadevan Pillai, D M PhaseAbstract:Preparation of nanostructured Tungsten Oxide thin films using the reactive pulsed laser ablation technique is re- ported. The structural, morphological, optical and electrical properties of deposited films are systematically studied by changing the ambient oxygen pressure (pO2). Structural depen- dence of Tungsten Oxide films on ambient oxygen pressure is discussed using grazing incidence X-ray diffraction (GIXRD) and micro-Raman spectra. The section analysis using atomic force microscopy exposed the smooth surface features of the deposited films. The blue shift in optical bandgap with an in- crease in ambient oxygen pressure is expounded in terms of electronic band structure of Tungsten Oxide. The influence of oxygen pressure on optical constants like extinction coefficient, band edge sharpness, refractive index and optical bandgap is also conveyed.The temperature variation of electrical resistance for films deposited at 0.12mbar furnishes evidence for its semi- conducting nature. PACS
Joon T Park - One of the best experts on this subject based on the ideXlab platform.
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synthesis and optical properties of colloidal Tungsten Oxide nanorods
Journal of the American Chemical Society, 2003Co-Authors: Joon T ParkAbstract:Thermal decomposition of W(CO)6 in oleylamine in the presence of mild oxidant Me3NO·2H2O produces Tungsten Oxide nanorods with diameters ranging from 3 to 6 nm. The size of nanorods can be easily varied by the employed surfactant ratio or reaction temperature. The prepared Tungsten Oxide nanorods exhibit strong photoluminescence (PL) peaks in 300−500 nm, which show a weak size dependency.
