Browse
Submit Data
Databases
API
Help

Dataset Information

20 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Induced 2H-Phase Formation and Low Thermal Conductivity by Reactive Spark Plasma Sintering of 1T-Phase Pristine and Co-Doped MoS2 Nanosheets.

ABSTRACT: Pristine and Co-doped MoS2 nanosheets, containing a dominant 1T phase, have been densified by spark plasma sintering (SPS) to produce a nanostructured arrangement. The structural analysis by X-ray powder diffraction revealed that the reactive sintering process transforms the 1T-MoS2 nanosheets into their stable 2H form despite a significantly reduced sintering temperature and time testifying to the fast kinetics of phase change. Together with the phase conversion, the SPS process promoted a strong texturing of the nanosheets, which drives additional scattering processes and alters the electronic and thermal transport properties. In the pristine sample, it produced one of the lowest thermal conductivities ever reported on MoS2 with a minimal value of 0.66 W/m·K at room temperature. The effect of Co substitution in the final sintered samples is not significant, compared to the pristine MoS2 sample, except for a non-negligible improvement of the electrical conductivity by a factor of 100 in the high-Co content (6% by mass) sample.

SUBMITTER: Bourges C

PROVIDER: S-EPMC8655900 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Phase-transfer induced room temperature ferromagnetic behavior in 1T@2H-MoSe2 nanosheets.

Project description:Manipulating electronic and magnetic properties of two-dimensional transitional-metal dichalcogenides has raised a lot of attention recently. Herein we report the synthesis and ferromagnetic properties of phase-transfer induced room temperature ferromagnetic behavior in 1 T@2H-MoSe2 nanosheets. Experimental results indicate the saturated magnetization of the 1 T@2H-MoSe2 compound increases first and then decreases as the increasing of 1 T-MoSe2 phase, where 65.58% 1 T-MoSe2 phase incorporation in 2H-MoSe2 could enhance the saturated magnetization from 0.32 memu/g to 8.36 memu/g. Besides, obvious magnetoresistance behaviors are observed in these samples, revealing their potential applications in future spintronics.

| S-EPMC5368601 | biostudies-literature

2H-SnS2 assembled with petaloid 1T@2H-MoS2 nanosheet heterostructures for room temperature NO2 gas sensing.

Project description:In this study, we explored the gas-sensing capabilities of MoS2 petaloid nanosheets in the metallic 1T phase with the commonly investigated semiconducting 2H phase. By synthesizing SnS2 nanoparticles and MoS2 petaloid nanosheets through a hydrothermal method, we achieve notable sensing performance for NO2 gas at room temperature (27 °C). This investigation represents a novel study, and to the best of our knowledge no, prior similar investigations have been reported in the literature for 1T@2HMoS2/SnS2 heterostructures for room temperature NO2 gas sensing. The formed heterostructure between SnS2 nanoparticles and petaloid MoS2 nanosheets exhibits synergistic effects, offering highly active sites for NO2 gas adsorption, consequently enhancing sensor response. Our sensor demonstrated a remarkable sensing response (Ra/Rg = 7.49) towards 1 ppm of NO2, rapid response time of 54 s, baseline recovery in 345 s, good selectivity and long-term stability, underscoring its potential for practical gas-sensing applications.

| S-EPMC11293367 | biostudies-literature

Direct solution-phase synthesis of 1T' WSe2 nanosheets.

Project description:Crystal phase control in layered transition metal dichalcogenides is central for exploiting their different electronic properties. Access to metastable crystal phases is limited as their direct synthesis is challenging, restricting the spectrum of reachable materials. Here, we demonstrate the solution phase synthesis of the metastable distorted octahedrally coordinated structure (1T' phase) of WSe2 nanosheets. We design a kinetically-controlled regime of colloidal synthesis to enable the formation of the metastable phase. 1T' WSe2 branched few-layered nanosheets are produced in high yield and in a reproducible and controlled manner. The 1T' phase is fully convertible into the semiconducting 2H phase upon thermal annealing at 400?°C. The 1T' WSe2 nanosheets demonstrate a metallic nature exhibited by an enhanced electrocatalytic activity for hydrogen evolution reaction as compared to the 2H WSe2 nanosheets and comparable to other 1T' phases. This synthesis design can potentially be extended to different materials providing direct access of metastable phases.

| S-EPMC6372596 | biostudies-literature

Microstructure and Electrical Properties of AZO/Graphene Nanosheets Fabricated by Spark Plasma Sintering.

Project description:In this study we report on the sintering behavior, microstructure and electrical properties of Al-doped ZnO ceramics containing 0-0.2 wt. % graphene sheets (AZO-GNSs) and processed using spark plasma sintering (SPS). Our results show that the addition of <0.25 wt. % GNSs enhances both the relative density and the electrical resistivity of AZO ceramics. In terms of the microstructure, the GNSs are distributed at grain boundaries. In addition, the GNSs are also present between ZnO and secondary phases (e.g., ZnAl₂O₄) and likely contribute to the measured enhancement of Hall mobility (up to 105.1 cm²·V-1·s-1) in these AZO ceramics. The minimum resistivity of the AZO-GNS composite ceramics is 3.1 × 10-4 Ω·cm which compares favorably to the value of AZO ceramics which typically have a resistivity of 1.7 × 10-3 Ω·cm.

| S-EPMC5509084 | biostudies-other

Simultaneous Spark Plasma Sintering of Multiple Complex Shapes.

Project description:This work addresses the two great challenges of the spark plasma sintering (SPS) process: The sintering of complex shapes and the simultaneous production of multiple parts. A new controllable interface method is employed to concurrently consolidate two nickel gear shapes by SPS. A graphite deformable sub-mold is specifically designed for the mutual densification of both complex parts in a unique 40 mm powder deformation space. An energy efficient SPS configuration is developed to allow the sintering of a large-scale powder assembly under electric current lower than 900 A. The stability of the developed process is studied by electro-thermal-mechanical (ETM) simulation. The ETM simulation reveals that homogeneous densification conditions can be attained by inserting an alumina powder at the sample/punches interfaces, enabling the energy efficient heating and the thermal confinement of the nickel powder. Finally, the feasibility of the fabrication of the two near net shape gears with a very homogeneous microstructure is demonstrated.

| S-EPMC6416649 | biostudies-literature

One-step assembly of 2H-1T MoS2:Cu/reduced graphene oxide nanosheets for highly efficient hydrogen evolution.

Project description:The transition metal dichagenides and their metallic 1T structure are attracting contemporary attentions for applications in high-performance devices because their peculiar optical and electrical properties. The single and few layers 1T structure is generally obtained by mechanical or chemical exfoliation. This work presents facile one-step synthesis of 2H-1T MoS2:Cu/reduced graphene oxide nanosheets. The experiment results indicated that the MoS2 and MoS2:Cu prepared by simple chemical solution reaction possessed 2H-1T structures. The reduced graphene oxide (rGO) incorporation further induced the phase transition from 2H-MoS2 to 1T-MoS2 and morphology transition from granular/nanosheet to more nanosheet. The 2H-1T structure and 2H → 1T phase transition, together with the Cu doping and interface effect between the MoS2 and rGO, remarkably enhanced the conduction and photoconduction of the nanostructures. Thus, Cu doping and rGO incorporation obviously enhanced the catalytic activity and its stability, making the MoS2:Cu/rGO nanosheet a most active and stable catalyst for hydrogen evolution. This work clearly indicates that the 1T-MoS2 nanosheets with high catalytic activity for hydrogen evolution can be easily obtained by the facile low temperature chemical method and induction of rGO.

| S-EPMC5390276 | biostudies-literature

Spark Plasma Sintering of LiFePO4: AC Field Suppressing Lithium Migration.

Project description:Our work proposes a comparison between Spark Plasma Sintering of LiFePO4 carried out using an Alternating Current (AC) and Direct Current (DC). It quantifies the Li-ion migration using DC, and it validates such hypothesis using impedance spectroscopy, X-ray photoelectron spectroscopy and inductively coupled plasma optical emission spectroscopy. The use of an AC field seems effective to inhibit undesired Li-ion migration and achieve high ionic conductivity as high as 4.5 × 10-3 S/cm, which exceeds by one order of magnitude samples processed under a DC field. These results anticipate the possibility of fabricating a high-performance all-solid-state Li-ion battery by preventing undesired Li loss during SPS processing.

| S-EPMC8198947 | biostudies-literature

Stable and scalable 1T MoS2 with low temperature-coefficient of resistance.

Project description:Monolithic realization of metallic 1T and semiconducting 2H phases makes MoS2 a potential candidate for future microelectronic circuits. A method for engineering a stable 1T phase from the 2H phase in a scalable manner and an in-depth electrical characterization of the 1T phase is wanting at large. Here we demonstrate a controllable and scalable 2H to 1T phase engineering technique for MoS2 using microwave plasma. Our method allows lithographically defining 1T regions on a 2H sample. The 1T samples show excellent temporal and thermal stability making it suitable for standard device fabrication techniques. We conduct both two-probe and four-probe electrical transport measurements on devices with back-gated field effect transistor geometry in a temperature range of 4?K to 300?K. The 1T samples exhibit Ohmic current-voltage characteristics in all temperature ranges without any dependence to the gate voltage, a signature of a metallic state. The sheet resistance of our 1T MoS2 sample is considerably lower and the carrier concentration is a few orders of magnitude higher than that of the 2H samples. In addition, our samples show negligible temperature dependence of resistance from 4?K to 300?K ruling out any hoping mediated or activated electrical transport.

| S-EPMC6102259 | biostudies-literature

New Synthesis Route for Complex Borides; Rapid Synthesis of Thermoelectric Yttrium Aluminoboride via Liquid-Phase Assisted Reactive Spark Plasma Sintering.

Project description:YxAlyB14 ceramics are of high interest as high temperature thermoelectric materials with excellent p, n control. In this study, direct synthesis of dense polycrystalline YxAlyB14 (x ~0.64, 0.52???y???0.67) ceramics was successfully carried out by spark plasma sintering using commercially available precursors. YB4, AlB2 and B powders were reactively sintered with an additive AlF3 at 1773 K for 5-60?min in reduced Ar atmosphere. The sinterability was remarkably enhanced by liquid phase sintering comparing to conventional synthesis techniques. Phase composition analysis by X-ray diffraction showed that main peaks belong to YxAlyB14 with the MgAlB14 structure type and no peaks of AlF3 were detected. The thermoelectric behavior was changed from p-type to n-type with increasing Al occupancy. Power factor and ZT values measured in this study were found to be in the same range as the best values previously reported. This original synthesis process is found to be less precursor-consuming as compared to previous synthesis processes, and strikingly, less time-consuming, as the synthesis time, is shortened from 8?h to 5?min for p-type and to 1?h for n-type. The total process time is shortened from ?3 days to ~4-5?h. This discovery opens the door for more accessible synthesis of complex borides.

| S-EPMC7265475 | biostudies-literature

1T-MoS2 Coordinated Bimetal Atoms as Active Centers to Facilitate Hydrogen Generation.

Project description:Anchoring single metal atoms has been demonstrated as an effective strategy to boost the catalytic performance of non-noble metal 1T-MoS2 towards hydrogen evolution reaction (HER). However, the dual active sites on 1T-MoS2 still remain a great challenge. Here, first-principles calculations were performed to systematically investigate the electrocatalytic HER activity of single and dual transition metal (TM) atoms bound to the 1T-MoS2 monolayer (TM@1T-MoS2). The resulted Ti@1T-MoS2 exhibits excellent structural stability, near-thermoneutral adsorption of H* and ultralow reaction barrier (0.15 eV). It is a promising single metal atom catalyst for HER, outperformed the reported Co, Ni and Pd anchoring species. Surprisingly, by further introducing Pd atoms coordinated with S atoms or S vacancies on the Ti@1T-MoS2 surface, the resulted catalyst not only maintains the high HER activity of Ti sites, but also achieves new dual active moiety due to the appropriate H* adsorption free energy on Pd sites. This work is of great significance for realizing dual active centers on 1T-MoS2 nanosheets and offers new thought for developing high-performance electrocatalysts for HER.

| S-EPMC8347348 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data