Synthesis of Novel Vanadium Oxide Nanotubes and Nanofibers

2002 ◽  
Vol 740 ◽  
Author(s):  
Samuel T. Lutta ◽  
Hong Dong ◽  
Peter Y. Zavalij ◽  
M. Stanley Whittingham
Keyword(s):  
Thermal Analysis ◽  
Vanadium Oxide ◽  
Electrochemical Behavior ◽  
Redox Reactions ◽  
Sol Gel ◽  
Vanadium Oxides ◽  
Organic Polymer ◽  
Fibrous Morphology ◽  
Surfactant Templates ◽  
Vanadium Oxide Nanotubes

ABSTRACTWe are exploring the synthesis and properties of structured vanadium oxides mainly nanotubes and nanorods. Nanotubes initially formed with surfactant templates have been readily exchanged with simple cations without change of the basal-plane structure. These compounds contain d-like vanadium oxide layers with the vanadium in VO6 octahedra. This structure is particularly suitable for redox reactions. In this paper we report on synthesis of vanadium oxide, (NH4)xV2O5-d·nH2O rods using organic polymer as template. This compound has been synthesized by sol-gel reaction and subsequent hydrothermal treatment. TGA, SEM, XRD and FTIR were used to characterize this compound. Thermal analysis of this compound shows that the fibrous morphology is maintained when it is heated in nitrogen and oxygen above 300 °C. However, in both cases the size of the fibers decreases. Performance of this compound as cathode material in secondary electrolyte has been investigated using LiPF6 as electrolyte. A capacity of 140 mAh/g was obtained which remained fairly constant with up to at least 10 cycles. We also investigated electrochemical behavior of thermal products.

Vanadium Oxide Nanofibers and Vanadium Oxide Polyaniline Nanocomposite: Preparation, Characterization and Electrochemical Behavior

2003 ◽  
Vol 788 ◽  
Author(s):  
Samuel T. Lutta ◽  
Hong Dong ◽  
Peter Y. Zavalij ◽  
M. Stanley Whittingham
Keyword(s):  
Vanadium Oxide ◽  
Hydrothermal Treatment ◽  
Electrochemical Behavior ◽  
Lithium Battery ◽  
Sol Gel ◽  
Active Material ◽  
Vanadium Oxides ◽  
Rechargeable Lithium Battery ◽  
Mixed Carbonate ◽  
Polyaniline Nanocomposite

ABSTRACTThe sol gel reaction of NH4VO3 and polymethylmethacrylate (PMMA) template followed by hydrothermal treatment formed (NH4)xV2O5-Δ.nH2O rods. TGA, SEM, XRD and FTIR characterized this compound. Heating (NH4)xV2O5-Δ.nH2O in oxygen and nitrogen at 250 °C and 300 °C respectively resulted in the formation of vanadium oxides nanofibers of V3O7 and V2O5. Performance of these compounds as cathode in rechargeable lithium battery was investigated in a LiPF6/mixed carbonate electrolyte. The materials show good cycling with capacity greater than 130mAh/g, which translates to the insertion of 0.5 moles of Li+ per vanadium of the active material.

Vanadium Oxide Nanotubes: Characterization and Electrochemical Behavior

2001 ◽  
Vol 703 ◽  
Author(s):  
Samuel T. Lutta ◽  
Arthur Dobley ◽  
Katana Ngala ◽  
Shoufeng Yang ◽  
Peter Y. Zavalij ◽  
...  
Keyword(s):  
Vanadium Oxide ◽  
Sol Gel ◽  
Interlayer Spacing ◽  
Inert Atmosphere ◽  
X Ray Diffraction ◽  
Ion Exchange Reaction ◽  
Transmission Electron ◽  
Redox Active ◽  
Vanadium Oxide Nanotubes ◽  
Tubular Morphology

ABSTRACTVanadium oxide nanotubes (VONT) were formed from vanadium (V) oxide and the dodecylamine templating agent by a sol-gel reaction and subsequent hydrothermal treatment. The nanotubes were characterized by transmission electron microscopy (TEM), electron diffraction, thermogravimetric analysis (TGA), infrared spectroscopy and powder X-ray diffraction (XRD). The nanotubes consist of VO2.4[C12H28N] 0.27 and range in diameter from 100 nm to150 nm. The study further reveals that the compound maintained the tubular morphology when heated at 430o C in an inert atmosphere. However, the tubular morphology is destroyed when the compound is heated at about 130°C in oxygen. Organic free manganese intercalated vanadium oxide nanotubes (MnVONT) were synthesized by an ion exchange reaction. The previously mentioned techniques were used to characterize MnVONT. Mn0.86V7O16+δ. nH2O layers have 2D tetragonal cell with a=6.157(3) Å, while interlayer spacing is 10.52 (3) Å. VONT, heated VONT and Mn0.86V7O16+δ. nH2O are redox - active and can insert lithium reversibly. This study reveals that the electrochemical performance of VONT is enhanced by removing the organic template by heating in an inert atmosphere or exchanging with Mn2+ ions.

scholarly journals Synthesis of Mo, W, and Mo- and W-Doped Multiwall VONTs via Sol-Gel and Hydrothermal Methods

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Roya Rouhani ◽  
Hamid Reza Aghabozorg ◽  
Mohsen Asadi Asadabad ◽  
Hossein Aghabozorg
Keyword(s):  
Vanadium Oxide ◽  
Hydrothermal Method ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Sem And Tem ◽  
Xrd Patterns ◽  
Vanadium Oxide Nanotubes ◽  
Hydrothermal Methods

Mo, W, and Mo and W were doped into multiwall vanadium oxide nanotubes. The syntheses were performed using sol-gel method followed by hydrothermal method. The synthesized samples were characterized by XRD, SEM, EDX, and TEM techniques. The XRD patterns of the synthesized samples indicated that Mo and W could be doped into VONTs totally up to 50%. The SEM and TEM images showed that the prepared samples have tubular and multiwall morphology and open ends.

Production of TiO2/Cr2O3 Composite Material in the Spherical Form

2019 ◽  
pp. 124-133
Author(s):  
A.O. Rogacheva ◽  
O.S. Khalipova ◽  
A.S. Brichkov ◽  
V.V. Kozik
Keyword(s):  
Thermal Analysis ◽  
Composite Material ◽  
Spectral Analysis ◽  
Sol Gel ◽  
Organic Polymer ◽  
Template Method ◽  
Ion Exchange Resins ◽  
Spherical Form ◽  
X Ray ◽  
Exchange Resins

Spherical TiO2/Cr2O3 oxides composites were obtained by template method accompanied with sol-gel method. Ion exchange resins of spherical form (TOKEM-100 and TOKEM-250) were used as an organic polymer matrix. Thermal analysis, X-ray phase analysis and micro-X-ray spectral analysis were used to identify the formation process and compositions of oxides composites. The formation of spherical oxide composite ends at 400 °C and the final products are a mixture of two oxides: Cr2O3 and TiO2 regardless of the structure of the used template. According SEM data prepared TiO2/Cr2O3 composites have spherical form and the size of sphere found to be in a range from 300 to 870 µm.

Electrochemical Behavior and Magnetic Properties of Vanadium Oxide Nanotubes

2011 ◽  
Vol 115 (13) ◽  
pp. 5265-5270 ◽  
Author(s):  
Andreia I. Popa ◽  
Evgenia Vavilova ◽  
Christine Täschner ◽  
Vladislav Kataev ◽  
Bernd Büchner ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Vanadium Oxide ◽  
Electrochemical Behavior ◽  
Vanadium Oxide Nanotubes

Vanadium Oxide Nanotubes with Diamine Templates

1999 ◽  
Vol 581 ◽  
Author(s):  
F. Krumeich ◽  
H.-J. Muhr ◽  
M. Niederberger ◽  
F. Bieri ◽  
M. Reinoso ◽  
...  
Keyword(s):  
Vanadium Oxide ◽  
Hydrothermal Treatment ◽  
Sol Gel ◽  
Exchange Reactions ◽  
Thin Walls ◽  
Synthesis Routes ◽  
High Yields ◽  
Vanadium Oxide Nanotubes ◽  
Tubular Morphology

ABSTRACTDiamine vanadium oxide nanotubes (DA-VOx-NTs) have been prepared in high yields applying two different synthesis routes, namely either a sol-gel reaction followed by a hydrothermal treatment or an exchange reaction. The first route is analogous to the well-known preparation of VOx-NTs containing monoamines: a vanadium(V) alkoxide is mixed with an α, ω- diamine (H2N[CH2]nNH2 with 12≤n≤20), the resulting adduct is hydrolyzed, and, after aging, a hydrothermal treatment leads to the nanotubes in pure form. The exchange of the monoamine template in VOx-NTs against diamines represents an alternative access to DA-VOx-NTs. This reaction occurs readily and is also applicable for diamines with short CH 2 chains like, e.g., in ethylene diamine. The TEM characterization of the DA-VOx-NTs confirms the tubular morphology which is widely preserved in the products of the exchange reactions. The characteristic feature of as-synthesized DA-VOx-NTs is a thick tube wall with many VO, layers while the exchange products are tubes comprising thin walls or bent packs of layers.

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

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