Shynthesis And Characterazation Of Vanadium Oxides And Their Derivate Compounds

One-dimensional nanostructures, such as nanorods, nanowires, nanotubes, nanosheets, and nanorings, have received considerable interest due to their novel physical and chemical properties which are different from their bulk counterparts. Vanadium oxides and their derivative compounds are of interest due to their redox-activity and layered structures, which allow the insertion of various intercalation species. In recent years, the fabrication of their nanostructures has been researched intensively due to their potential applications in lithium batteries, chemical sensors or actuators, and nanodevices. In this paper, we reported several synthesis methods of some typical vanadium oxides and their derivate compounds. The growth mechanism and properties had been discussed.H₂V₃O₈ single-crystal nanobelts were synthesized by hydrothermal processing of bulky V₂O₅ powders in hydrochloric acid solution without the aid of any templates or reducing agents. H₂V₃O₈ nanobelts were metastable and can be transformed to V₂O₅ nanobelts in oxygen at 500°C. Orthorhombic V₂O₅ single-crystalline nanobelts were synthesized in the H₂O₂ aqueous solution by the same methods. The products were very pure, and the process was environmentally friendly for no impure ions, harmful reagents in the reaction solution. A probable dehydration-recrystallization-cleavage mechanism for the formation of V₂O₅ nanobelts was proposed. The growth direction of V₂O₅ nanobelts was different to that one which was prapared by sintering H₂V₃O₈ nanobelts. The experiments also demonstrated that the use of nanosized belt-like structured materials can considerably enhanced the specific discharge capacity in lithium-ion batteries.Vanadium Oxide Bronzes, such as Ba(VO₃)₂·H₂O single-crystal nanobelts, Ba_1+xV₆O₁₆·nH₂O nanobelts and seamless ring-like structures, Cu_xV₂O₅, were prapared by hydrothermal methods. Ba(VO₃)₂·H₂O nanobelts were obtained by treating V₂O₅ powders and Ba(OH)₂·8H₂O with CTMA as the surfactant. Ba_1+xV₆O₁₆·nH₂O was formed by hydrothermal treating Ba₃(V₁₀O₂₈)(H₂O)₁₉ precursor, and it is interesting that, there were several types rings in the Ba_1+xV₆O₁₆·nH₂O products, such as plate-like, tube-like, doughnut-like and wheel-like morphologies. To our knowledge that, it is the first time to report that vanadate ring-like structures can be synthesized by simple hydrothermal method without any template. Cu_xV₂O₅, prapared from V₂O₅/H₂O₂ as the vanadium source, was a perfect anode lithium material and has higher specific capacity, which can be seriously effected by the content of copper.Polyaniline-vanadium oxide nanocomposite nanosheets were prepared via an in-situ intercalation polymerization process. The interplanar spacing was increased from 4.38A to 13.8A after intercalation reaction. During the reaction, the bulk V₂O₅ powders were intercalated and exfoliated by the reaction of aniline oxidated polymerization, and form the tremeUa-like structure.