Arthur Dobley

Sodium trivanadium(III) bis(sulfate) hexahydroxide

The title compound, NaV(3)(SO(4))(2)(OH)(6), was synthesized and found to crystallize in the trigonal space group R-3m with the Na atom at a site with 3;m symmetry, the V atom at a site with 2/m symmetry, and the S and a terminal O atom at sites with 3m symmetry; the remaining two O atoms and the H atom are at sites with m symmetry. Octahedrally coordinated vanadium and tetrahedral sulfate ions share corners to form layers that are held together by hydrogen bonds and by sodium ions, which are located between the layers.

Low Temperature Synthesis of Lamellar Transition Metal Oxides Containing Surfactant Ions

Recently there has been much interest in reacting vanadium oxides hydrothermally with cationic surfactants to form novel layered compounds. A series of new transition metal oxides, however, has also been formed at or near room temperature in open containers. Synthesis, characterization, and proposed mechanisms of formation are the focus of this work. Low temperature reactions of vanadium pentoxide and ammonium (DTA) transition metal oxides with long chain amine surfactants, such as dodecyltrimethylammonium bromide yielded interesting new products many of which are layered phases. DTA{sub 4}H{sub 2}V{sub 10}O{sub 28}{center_dot}8H{sub 2}O, a layered highly crystalline phase, is the first such phase for which a single crystal X-ray structure has been determined. The unit cell for this material was found to be triclinic with space group P {bar 1} and dimensions a = 9.895(1){angstrom}, b = 11.596(1){angstrom}, c = 21.924(1){angstrom}, {alpha} = 95.153(2){degree}, {beta} = 93.778(1){degree}, and {gamma} = 101.360(1){degree}. Additionally, the authors synthesized a dichromate phase and a manganese chloride layered phase, with interlayer spacings of 26.8{angstrom}, and 28.7{angstrom} respectively. The structure, composition, and synthesis of the vanadium compound are described, as well as the synthesis and preliminary characterization of the new chromium and manganese materials.

Vanadium Oxide Nanotubes: Characterization and Electrochemical Behavior

Abstract : Vanadium 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 VO2.4C12H28N0.27 and range in diameter from 100 nm to 150 nm. The study further reveals that the compound maintained the tubular morphology when heated at 430 deg C in an inert atmosphere. However, the tubular morphology is destroyed when the compound is heated at about 130 deg 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. Mn(0.86)V7O(16+sigma). nH2O layers have 2D tetragonal cell with a = 6.157(3) A, while interlayer spacing is 10.52 (3) A. VONT, heated VONT and Mn(0.86)V7C(16+sigma). 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 Mn(2+) ions.