- Preparation and properties of titanium trisulfide nanoparticles
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Stable colloidal dispersions with a 2 mM TiS3 concentration (300 mg/l) are obtained by ultrasonic treatment of TiS3 in acetonitrile and isopropyl alcohol and characterized by physicochemical methods. The electrical double layers for the particles in dispersions are estimated from the measured ζ-potentials, and the energies of interparticle interactions are calculated based on the Derjaguin–Landau–Verwey–Overbeek theory. The structural and spectroscopic identity of the particles and crystalline TiS3 is demonstrated for the solid phases obtained from the dispersions.
- Poltarak,Poltarak,Artemkina,Podlipskaya, T. Yu.,Fedorov
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- REVERSIBILITY OF SODIUM INSERTION IN TRANSITION METAL TRISULFIDES.
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The effects produced by the insertion of sodium in the trisulfides of titanium, niobium, and tantalum were investigated by electrochemical techniques. Cyclic voltammetry measurement were carried out in these materials using high-temperature sodium cells w
- Zanini
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- PHOTOELECTROCHEMICAL STUDY OF TiS3 IN AQUEOUS SOLUTION.
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TiS//3 single crystals have been grown by chemical vapor transport. They were characterized by X-ray diffraction and measurement of their electronic transport properties. A photoelectrochemical study shows both anodic and cathodic dark currents and anodic photocurrents. Flat-band potentials and anodic corrosion potentials in acidic and basic solutions and in the presence of an I//3** minus /I** minus redox couple have been determined from the onset of photocurrent and from the Schottky-Mott plot of capacitance. The flat-band potential exhibits a pH dependence but is almost independent of the presence of I** minus in solution. The stability of this material in a 1N H//2SO//4 plus 1N I//3** minus /I** minus solution has been observed for a period of fourteen days with a photocurrent of approximately 1mA/cm**2. A particular photocorrosion mechanism is reported. The reaction starts at the edges of the layer and proceeds toward the interior. These mechanisms are discussed in relation to the existence of two types of S atoms in the structure: sulfur dimers and S**2** minus ions.
- Gorochov,Katty,Le Nagard,Levy-Clement,Schleich
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- Novel low temperature synthesis of titanium sulfide
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Amorphous titanium sulfides were synthesized by the direct reaction between dry organic sulfurizing agents and TiCl4. A detailed discussion is given about the reactivity of TiCl4 with each sulfurizing agent. All of the usual crystalline titanium sulfide phases (Ti3S4, TiS2, TiS3) were also synthesized by simply heating the obtained amorphous powder or by heating this powder in the presence of sulfur. These reactions occurred very rapidly and allowed for the simple synthesis of all the crystalline phases.
- Bensalem,Schleich
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- Crystal structure of 3R-LiTiS2 and its stability compared to other polymorphs
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The crystal structure of 3R-LiTiS2 was studied with combined experimental and theoretical approaches. The 3R polymorph of lithium titanium disulfide crystallizes rhombohedrally in the well-known NaCrS2 type with lattice parameters a = 352.98(1) pm, c = 1807.51(3) pm. The relative stability of 3R-LiTiS2 with respect to other known and hypothetical polymorphs was evaluated theoretically at DFT level employing the hybrid method B3LYP. 3R-LiTiS2 is less stable than the most common 1T phase (by 4 kJ·mol-1), and is more stable (by 5 kJ·mol -1) than the known phase c-LiTiS2 thus confirming the importance of this phase for further investigations.
- Nakhal, Suliman,Lerch, Martin,Koopman, Jeroen,Islam, Mazharul M.,Bredow, Thomas
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- An X-ray spectrscopy study of the electronic structure of TiS3
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X-ray photoemission and absorption spectra of TiS3 are studied. The temperature dependence of the magnetic susceptibility is measured and the electron density of states is calculated. Titanium ions in different oxidation states are found to coe
- Shkvarin,Yarmoshenko,Yablonskikh,Merentsov,Titov
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- Polarized X-ray absorption spectroscopy and XPS of TiS3: S K- and Ti L-edge XANES and S and Ti 2p XPS
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Sulfur and Ti 2p XPS and polarized S K- and L2,3- and Ti L 2,3-edge XANES spectra have been obtained from oriented ribbon-like crystals of TiS3 grown by vapor transport. The S 2p XPS spectrum for (0 0 1) crystal faces has line widths of 0.53 eV and is completely accounted for by partially overlapped 2p3/2/2p1/2 doublets for sulfide (S2-) and disulfide (S22-) species, which are separate and independent entities in TiS3. Evidence of unsaturated surface states is lacking, consistent with a surface monolayer for the (0 0 1) growth face of disulfide atoms oriented with their charge-neutral sides outward. The S K-edge XANES spectra show pronounced anisotropy in the (0 0 1) plane of TiS3 crystals, associated with the photoelectron transition channel S 1s→3pxσ*u with the electric vector (E) parallel the a-axis (and the S-S bond of the disulfide group), and transitions to unoccupied antibonding orbitals of S-Ti bonds with E parallel to the b-axis (the direction of the well-known quasi-one-dimensional character of TiS3). The XPS and ultrasoft and soft X-ray region XANES spectra confirm the surface and near-surface structural integrity of TiS3.
- Fleet,Harmer,Liu,Nesbitt
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- STRUCTURAL, OPTICAL, AND ELECTRONIC PROPERTIES OF Li//3MS//3 COMPOUNDS (M**I**I**I equals Ti,Zr,Hf).
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The Li//3MS//3 powder samples (M**I**I**I equals Ti,Zr,Hf), chemically prepared under mild conditions, have been studied by X-ray diffraction, infrared and Raman vibrational spectroscopies, UV-visible absorption, and electron paramagnetic resonance (EPR) technics. From X-ray data we confirm the topochemical mechanism of three lithium insertions into the 2D-MS//3 host lattices already proposed by R. R. Chianelli and M. B. Dines. From infrared and Raman results new structural information is obtained: on the one hand, the cleavage of (S//2)**2** minus pairs induces a new arrangement of the basic structure and on the other hand, Li-S interactions are by far predominant within strongly distorted two LiS//4 and one LiS// 6 groups; moreover M-S interactions are markedly weakened.
- Sourisseau, C.,Gwet, S. P.,Gard, P.,Mathey, Y.
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- Bundle of nanobelts up to 4 cm in length: One-step synthesis and preparation of titanium trisulfide (TiS3) nanomaterials
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One-dimensional (1D) titanium trisulfide (TiS3) nanobelt bundles up to 4 cm in length have been successfully synthesized through an easy and common chemical vapor transition (CVT) process. The as-synthesized samples were characterized by X-ray powder diffraction (XRD), polarized light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). All microscopic observations indicated a belt-like morphology. Powder XRD patterns showed that TiS3 crystallized in the monoclinic system with a = 4.958(1) A, b = 3.393(1) A, c = 8.793(3) A and β = 97.27(5)°. TEM images revealed a nanostructure with an interplanar spacing of 0.87 nm. The ED pattern and HRTEM images confirmed the [014] elongated direction and the [001] dilated direction of the bundle of TiS3 nanobelts. Its tensile strength (TS) was further examined with a universal testing machine with 20 N as the biggest strength: the maximum stress and the break strain were 111.027 MPa and 97.1 %, respectively. Because the TiS 3 nanocrystals are up to 4 cm in length and flexible enough to be cut into small pieces, they should be used directly in electrical and electronic applications. Also, these nanomaterials are synthesized and prepared by a simple one-step process. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Ma, Jingjing,Liu, Xiaoyang,Cao, Xuejing,Feng, Shouhua,Fleet, Michael E.
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- Modification of electronic structure by charge transfer and molecular motion in titanium disulfide-ethylenediamine intercalation compound
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An attempt at modifying the electronic conduction mechanism by guest-host charge transfer and thermally excited molecular motion reported. Ethylenediamine was intercalated into a semiconducting layered material, titanium disulfide, and a significant increase in charge carriers was evidenced by metallic conductivity, Pauli paramagnetism, and conduction electron spin resonance. Rotational motion of the guest molecule was evidenced by the proton spin-lattice relaxation measurement. However, no anomalous behaviors were found on the electronic properties which are attributable to motion-induced modification of the electronic state.
- Ogata,Fujimori,Miyajima,Kobashi,Chiba,Taylor,Endo
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- CRYSTAL GROWTH, CHARACTERIZATION AND PHOTOELECTROCHEMICAL PROPERTIES OF Zr1 - xTixS3 (0 less than x less than . 33).
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The authors report on the crystal growth conditions, transport properties and preliminary photoelectrochemical properties of Zr//1// minus //xTi//xS//3 crystals of composition x equals . 07, . 15, . 25, . 33. Their properties are compared to those of pure ZrS//3. It has been found that their resistivity decreases with increasing titanium content, and that the onset of photoresponse shifts to lower energies with a significant rise in quantum efficiency. It is suggested that these results are related to the formation of a lower-energy band consisting of titanium-like orbitals.
- Sieber,Fotouhi,Gorochov
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- Photothermal catalytic properties of layered titanium chalcogenide nanomaterials
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The search for novel photocatalysts that make use of almost the entire solar spectrum remains an ongoing task to achieve high efficiency in energy conversion. While titanium chalcogenides offer a variety of phase compositions with different photophysical properties, their photocatalytic performance in pollutant degradation has not been investigated to date. In contrast to the model photocatalyst titanium dioxide, titanium chalcogenides possess small band gaps which make them eligible to absorb light in the visible range up to the near-infrared region, thus making them interesting candidates for photocatalysis. Herein titanium chalcogenide-based photocatalysts are synthesized by the chemical vapor transport (CVT) method and studied for their photocatalytic activity towards pollutant degradation. A series of titanium chalcogenides TiXn (X = S, n = 1-3; X = Se, n = 2; X = Te, n = 1) have been characterized by a variety of physico-chemical methods. Due to the expected non-stoichiometry of some titanium sulfides, they offer a large number of defect states which make them interesting candidates for photocatalysis. Thus, these titanium-chalcogenides were systematically studied for the photocatalytic degradation of pollutants using methyl orange dye as the test pollutant under simulated sunlight. Particularly TiS and TiS3 show high photocatalytic and thermocatalytic activity, outperforming the activity of titanium dioxide (pure anatase). By controlling the ratios of titanium and chalcogen elements and the specific reaction conditions, a variety of titanium chalcogenides with different compositions and phases showing a high photocatalytic activity can be accessed. Furthermore, it is found that the formation of a titanium dioxide passivation layer during photocatalysis results in a titanium oxide/titanium sulfide heterostructure. This allows further enhancement of the photocatalytic and thermocatalytic activity compared to the bare Ti-chalcogenides.
- Okeil, Sherif,Yadav, Sandeep,Bruns, Michael,Zintler, Alexander,Molina-Luna, Leopoldo,Schneider, J?rg J.
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- New Solid-Gas Metathetical Synthesis of Binary Metal Polysulfides and Sulfides at Intermediate Temperatures: Utilization of Boron Sulfides
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A new simple synthetic method for binary metal polysulfides and sulfides was developed by utilizing an in situ formation of boron sulfides and their subsequent reactions with metal-source oxides in a closed container at intermediate temperatures above 350 °C at which the boron sulfides react in a gaseous form. The versatility of the new method is demonstrated with oxides of various transition metals (Ti, V, Mn, Fe, Ni, Nb, Mo, Ru, and W) and rare-earth metals (Y, Ce, Nd, Sm, Eu, Tb, and Er) as starting materials that exhibit different chemical characteristics. Regardless of the oxidation states of metals in the starting materials, the sulfidation reactions occurred quantitatively with stoichiometric mixtures of boron and sulfur, and within 24 h the reactions yielded pure products of TiS2, TiS3, VS4, FeS2, NiS2, NbS3, MoS 2, RuS2, WS2, Y2S3, and RS2 (R = Ce, Nd, Sm, Eu, Tb, and Er) which were the thermodynamically stable phases under the reaction conditions. The scope and implications of the new sulfidation method are also discussed.
- Wu, Li-Ming,Seo, Dong-Kyun
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p. 4676 - 4681
(2007/10/03)
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- Synthesis and Investigation of Titanium Disulfide of Varied Stoichiometry
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This article presents the results of investigation of interaction between titanium and sulfur in a confined volume by chemical analysis, DTA, X-ray powder diffraction, and IR spectroscopy. It is shown that the temperature schedule of synthesis and the annealing conditions are the factors determining the stoichiometry and unit cell parameters of titanium disulfide.
- Kompanichenko,Omel'chuk,Khomenko
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p. 323 - 325
(2008/10/08)
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- High-temperature interactions of transition-metal carbides with Na2SO4
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The high-temperature (900-1200 K) interaction of transition-metal carbides namely Cr7C3, Fe3C, TiC, ZrC, NbC, TaC, MoC, WC, VC and HfC with Na2SO4 has been studied in a stream of pure and dried oxygen gas. Thermogravimetric studies were carried out by measuring the weight change as a function of time and mole fraction of Na2SO4 in the reaction mixture. The presence of different constituents in the reaction products were identified by X-ray diffraction analysis and the morphologies of the reaction products were discussed on the basis of metallography, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). The quantitative determination of soluble metal species in the aqueous solutions of Na2SO4-transition-metal carbide products was carried out by atomic absorption spectroscopy. At high temperatures, transition-metal carbides interact with Na2SO4, forming metal oxides. The resulting metal oxide interacts with Na2SO4 forming a soluble sodium metal oxide or a metal sulphide depending upon the local condition prevailing during the reaction.
- Mobin, M.,Malik, A. U.
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p. 243 - 254
(2008/10/08)
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