12067-66-2Relevant academic research and scientific papers
Microwave-assisted synthesis of few-layered TaTe2 and its application as supercapacitor
Chakravarty, Disha,Kumar, Praveen,Ugale, Vaishali S.,Late, Dattatray J.
, p. 1598 - 1603 (2015)
We report a simple and rapid microwave-assisted synthesis of tantalum telluride (TaTe2) nanosheets. The ratio of tantalum pentachloride (TaCl5) and elemental tellurium (Te) powder were adjusted in the presence of NaBH4 in such a way as to obtain the TaTe2 nanosheet. The samples were characterized by various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), UV/Vis spectroscopy, photoluminescence (PL) spectroscopy, and XRD. Our SEM, TEM, and AFM results show the formation of sheet-like morphology, while the XRD data confirms the high crystalline quality and stable phase of the TaTe2 formed. The supercapacitor cells were fabricated by using TaTe2 nanosheets as anode material, platinum metal wire as a counterelectrode, and Ag/AgCl as reference electrode. The calculated coulombic efficiency is more than 95 , while the cycle-to-cycle decrease in capacity is less than 5 . The maximum discharge or charging capacity is below 2.4 Wh/kg, which is an ideal characteristic for achieving supercapacitor behavior. The first experimental investigations on the use of microwave to synthesize atomically thin few-layer TaTe2 nanosheets are described. This material also shows good performance as a supercapacitor.
Ta5Se1.2Te1.8 - A tetrahedrally close-packed metal-rich layer structure
Conrad,Harbrecht
, p. 742 - 748 (1997)
Ta5Se1.2Te1.8 was prepared by reducing a mixture of TaSe2 and TaTe2 with tantalum at 1540°C. A X-ray single crystal structure analysis was performed. Space group: P1, a = 1008.5(4) pm, b = 1052.1(4) pm, c = 1440.2(5) pm, α = 90.32(2)°, β = 96.42(2)°, γ = 108.28(2), Z = 8, Pearson-Symbol: aP64, 5684 reflexions, 300 variables, R1 = 0.066. The structure is built up of hetero-nuclear, distorted icosahedral clusters penetrating mutually into pentagonal anti-prismatic columns. The connection of these units by inter-columnar Ta-Ta-and Ta-Se,Te-contacts affords tetrahedral close-packed layers. The chalcogen atoms are one-sidedly coordinated by three, four or six tantalum atoms.
Synthesis of tantalum tellurides. The crystal structure of Ta2Te3
Conrad, Mathias,Harbrecht, Bernd
, p. 181 - 192 (1992)
Ta2Te3 was prepared by reducing TaTe2 with tantalum at 1350 K in a sealed molybdenum crucible. Ta2Te3 disproportionates above 1420 K yielding the ditelluride and as yet unknown Ta6Te5. The stability limit for the substitutional sesquitellurides NbxTa2-xTe3 is reached at x = 1. The novel layered-type structure of Ta2Te3 (C 2/m, N = 4; a = 2049.5(3) pm, b = 349.96(4) pm, c = 1223.7(2) pm, β = 143.74(1)° (Guinier), N(I0) = 762 with I0 > 2?(I0), 32 variables, R = 0.032) can be considered a stuffed variant of a molybdenite structure type. It consists of corrugated layers ∞2(Te-Ta4/3-Te) which, according to the shortest interlayer contacts Te-Te (372.9 pm), order via van der Waals interactions. Extended homonuclear bonding regions (297.1 pm ≤ dTa-Ta ≤ 309.7 pm) within the metal layers contribute to the stability of the metallic sesquitelluride.
Growth of Transition-Metal Dichalcogenides by Solvent Evaporation Technique
Abdel-Hafiez, Mahmoud,Chareev, Dmitriy A.,Evstigneeva, Polina,Man, Gabriel J.,Phuyal, Dibya,Rensmo, H?kan,Vasiliev, Alexander N.
, p. 6930 - 6938 (2020/11/09)
Due to their physical properties and potential applications in energy conversion and storage, transition-metal dichalcogenides (TMDs) have garnered substantial interest in recent years. Among this class of materials, TMDs based on molybdenum, tungsten, sulfur, and selenium are particularly attractive due to their semiconducting properties and the availability of bottom-up synthesis techniques. Here we report a method which yields high-quality crystals of transition-metal diselenide and ditelluride compounds (PtTe2, PdTe2, NiTe2, TaTe2, TiTe2, RuTe2, PtSe2, PdSe2, NbSe2, TiSe2, VSe2, ReSe2) from their solid solutions, via vapor deposition from a metal-saturated chalcogen melt. Additionally, we show the synthesis of rare-earth-metal polychalcogenides and NbS2 crystals using the aforementioned process. Most of the crystals obtained have a layered CdI2 structure. We have investigated the physical properties of selected crystals and compared them to state of the art findings reported in the literature. Remarkably, the charge density wave transition in 1T-TiSe2 and 2H-NbSe2 crystals is well-defined at TCDW ≈ 200 and 33 K, respectively. Angle-resolved photoelectron spectroscopy and electron diffraction are used to directly access the electronic and crystal structures of PtTe2 single crystals and yield state of the art measurements.
Cytotoxicity of Group 5 Transition Metal Ditellurides (MTe2; M=V, Nb, Ta)
Chia, Hui Ling,Latiff, Naziah Mohamad,Sofer, Zden?k,Pumera, Martin
supporting information, p. 206 - 211 (2017/12/04)
Much research effort has been put in to study layered compounds with transition metal dichalcogenides (TMDs) being one of the most studied compounds. Due to their extraordinary properties such as excellent electrochemical properties, tuneable band gaps, a
Synthesis, structure, and properties of the tantalum-rich suicide chalcogenides Ta15Si2QxTe10-x (Q = S, Se)
Debus, Stephan,Harbrecht, Bernd
, p. 431 - 438 (2008/10/08)
The quaternary tantalum suicide chalcogenides Ta15Si2QxTe10-x (Q = S, Se) are accessible from proper, compacted mixtures of the respective dichalcogenides, silicon and elemental tantalum at 1770 K in sealed molybdenum tubes. The structures were determined from the strongest X-ray intensities of fibrous crystals with cross sections of about 3 μm and confirmed by fitting the profile of single phase X-ray diffractograms. The phases Ta15Si2S3.5Te6.5 and Ta15Si2. Se3.5Te6.5 crystallize in the monoclinic space group C2/m with two formula units per unit cell, a = 2393.7(1) pm, b = 350.08(2) pm, c = 1601.2(1) pm, β = 124.700(4)°, and a = 2461.3(2) pm, b = 351.70(2) pm, c= 1601.7(1) pm, β = 124.363(5)°, respectively. Tri-capped trigonal prismatic Ta9Si clusters stabilized by encapsulated Si atoms can be seen as the characteristic unit of the structure. The clusters are fused into twin columns which are connected by additional Ta atoms, thus forming corrugated layers. The remaining valences at the surfaces of the layered Ta-Si substructure are saturated by those of chalcogen atoms which are coordinated only from one side by three, four or five Ta atoms. Few bridging covalent Ta-S-Ta and Ta-Se-Ta bonds and, otherwise, dispersive interactions between the Q atoms hold these nearly one nanometer wide slabs together. The phases are moderate metallic conductors. There is no evidence for any electronic instability within 10-310 K in spite of the high anisotropy of the structures. Wiley-VCH Verlag GmbH, 2001.
The metal-rich layer structure of Ta6STe3
Debus,Harbrecht
, p. 173 - 179 (2008/10/08)
Ta6S1+xTe3-x was prepared from an appropriate mixture of 2H-Ta1.3S2, TaTe2, and Ta in a fused tantalum tube at 1273 K within 3 d. The results of a X-ray single crystal structure analysis for a phase near the Te-rich limit of the homogeneity range are reported. Ta6S1.00Te3.00(1) crystallizes in the triclinic space group P1?, a = 993.14(8) pm, b = 1032.18(8) pm, c = 1378.78(11) pm, α = 79.32(1)°, β= 81.36(1)°, γ = 85.74(1)°, Z = 6, Pearson symbol aP60, 6048 Io > 2σ (Io), 286 variables, wR2 = 0.067. The metal-rich layer structure of Ta6STe3 comprises distorted icosahedral Ta13 clusters and related deltahedral cluster fragments complemented by chalcogen atoms. The centred clusters consist of 11, 12, 13, 14, or 16 atoms. They interpenetrate into lamellae in which the tantalum and chalcogen atoms are spatially segregated according to 2∞[Q-Ta3-Q]. The signature of the structure is a lenticular heptagonal antiprismatic Ta30 cluster which seems to be excised from the pentagonal antiprismatic columnar structure of Ta6S. The Ta30 clusters and distorted icosahedral Ta13 clusters are connected and fused into puckered layers. The rest of the tantalum valences are used for heteronuclear bonding. The chalcogen atoms having three to six next tantalum atoms coat the corrugated, tetrahedrally close-packed layers. Ta6STe3 is a moderate metallic conductor (P293 K = 3 x 10-4 Ωcm) exhibiting typical temperature independent paramagnetic properties.
Solid-state tellurium-125 nuclear magnetic resonance studies of transition-metal ditellurides
Orion, Isabelle,Rocha, Joao,Jobic, Stephane,Abadie, Virginie,Brec, Raymond,Fernandez, Christian,Amoureux, Jean-Paul
, p. 3741 - 3748 (2007/10/03)
Solid-state 125Te NMR studies of inorganic compounds containing tellurium in oxidations states ranging from -II to VI have been made. The chemical shift tensors of Te(OH)6, TeCl4, TeO2 and elemental tellurium ha
125Te Moessbauer spectroscopic study of layered transition metal ditellurides with interlayer communication
Guzman, R.,Morales, J.,Tirado, J. L.,Moubtassim, M. L. Elidrissi,Jumas, J. C.,Langouche, G.
, p. 911 - 914 (2008/10/08)
The 125Te Moessbauer spectroscopy of different 1T-transition metal ditellurides shows that the values of the isomer shift are dependent on the degree of the Te-Te interlayer interactions which decrease the 5p population by Te(p)-M(d) electron d
