Showing papers on "Ammonium tetrathiomolybdate published in 2019"
TL;DR: In this article, a simple strategy to synthesize the hierarchical MoS2/Ti3C2Tx hybrid by combining liquid nitrogen-freezing and subsequent annealing was reported.
Abstract: Developing highly efficient noble-metal-free electrocatalysts for hydrogen evolution reaction (HER) has attracted increasing attentions. Here, we report a simple strategy to synthesize the hierarchical “nanoroll” like MoS2/Ti3C2Tx hybrid by combining liquid nitrogen-freezing and subsequent annealing. The quick freezing of the Ti3C2Tx nanosheets and ammonium tetrathiomolybdate mixture causes a sudden change in the strain of Ti3C2Tx, which leads to an interesting “nanoroll” like hierarchical structure. After annealing at H2/Ar atmosphere, vertically aligned molybdenum sulfide (MoS2) crystallites are in situ formed in and on the nanoroll like Ti3C2Tx. Notably, this hierarchical MoS2/Ti3C2Tx hybrid exhibits excellent HER catalytic activity with a small onset overpotential of 30 mV, and a more than 25-fold increase in the exchange current density compared with MoS2 was observed.
195 citations
11 Mar 2019
TL;DR: Bi2Te3-MoS2 layered heterostructures have been prepared by a hydrothermal reaction of ammonium tetrathiomolybdate with hydrazine as mentioned in this paper.
Abstract: Bi2Te3–MoS2 layered heterostructures have been prepared by a hydrothermal reaction of ammonium tetrathiomolybdate with hydrazine in the presence of preformed Bi2Te3 hexagonal nanoplatelets as templ...
15 citations
TL;DR: In this paper, the impact of ammonium tetrathiomolybdate ((NH4)2MoS4) on the tribological behavior of choline ricinoleate ionic liquid (cho-ricinoleates) in water-glycerol mixture was investigated.
Abstract: Ammonium tetrathiomolybdate ((NH4)2MoS4) is usually used as a precursor for preparing MoS2 nanomaterials. Herein, we added (NH4)2MoS4 to water-glycerol mixture containing choline ricinoleate ionic liquid ([cho][ricinoleate]) and investigated the impact of (NH4)2MoS4 on the tribological behavior of [cho][ricinoleate] in water-glycerol mixture considering different factors including concentration, load, and temperature. There are significant synergistic effects between (NH4)2MoS4 and [cho][ricinoleate] on the lubricity: a small amount of (NH4)2MoS4 can remarkably enhancing the antiwear and friction-reducing properties of [cho][ricinoleate] in water-based fluid, and the optimal concentration of (NH4)2MoS4 is 0.01%. The antiwear capability of the optimal formulation increases with the increase of temperature and load. We further carried out SEM–EDS, Raman, and XPS analyses of the wear tracks to investigate the underlying lubrication mechanism. The dominant improvement of (NH4)2MoS4 on the lubricating ability of [cho][ricinoleate] in water-glycerol mixture is ascribed to the generation of the stable hybrid tribofilm consisting of the carbon film, MoS2, FeS2, and Mo oxides.
6 citations
Patent•
06 Sep 2019
TL;DR: In this article, a three-dimensional nitrogen-doped transition metal oxide/nickel sulfide composite catalyst was proposed, which consists of nickel foam, nitrogen doped metal oxide and nickelsulfide.
Abstract: The invention discloses a three-dimensional nitrogen-doped transition metal oxide/nickel sulfide composite catalyst. The catalyst includes nickel foam, nitrogen-doped transition metal oxide and nickelsulfide, wherein the nickel foam serves as a substrate, and the nitrogen-doped transition metal oxide grows on the nickel foam in situ. The invention further discloses a preparation method of the three-dimensional nitrogen-doped transition metal oxide/nickel sulfide composite catalyst. The method includes the following steps that the nickel foam substrate is impregnated in an ammonium tetrathiomolybdate solution and dried after impregnation, and an ammonium tetrathiomolybdate contained nickel foam precursor is obtained; the nickel foam precursor is subjected to vacuum high-temperature calcination, and the molybdenum dioxide/nickel sulfide composite catalyst is obtained; the molybdenum dioxide/nickel sulfide composite materials are subjected to thermal ammoniation, and the three-dimensional nitrogen-doped transition metal oxide/nickel sulfide composite catalyst is obtained. The invention further provides the application of the composite catalyst as a cathode catalyst material in an electrolytic water cathode HER reaction, the composite catalyst shows excellent electrocatalytic performance in alkaline electrolyte and has good stability, and the possibility of hydrogen energy development and utilization is further improved.
6 citations
TL;DR: A simple and scalable fabrication process for defect-rich MoS2 directly from ammonium tetrathiomolybdate precursor using intense pulse light treatment in milliseconds durations is demonstrated, showing high activity for the hydrogen evolution reaction (HER) in acidic media.
Abstract: We have demonstrated a simple and scalable fabrication process for defect-rich MoS2 directly from ammonium tetrathiomolybdate precursor using intense pulse light treatment in milliseconds durations. The formation of MoS2 from the precursor film after intense pulsed light exposure was confirmed with XPS, XRD, electron microscopy and Raman spectroscopy. The resulting material exhibited high activity for the hydrogen evolution reaction (HER) in acidic media, requiring merely 200 mV overpotential to reach a current density of 10 mA cm-2. Additionally, the catalyst remained highly active for HER over extended durability testing with the overpotential increasing by 28 mV following 1000 cycles. The roll-to-roll amenable fabrication of this highly-active material could be adapted for mass production of electrodes comprised of earth-abundant materials for water splitting applications.
6 citations
Patent•
08 Jan 2019
TL;DR: In this paper, an amorphous phase molybdenum trisulfide cathode material of a lithium sulfide battery and a preparation method thereof was provided, which adopts porous hollow carbon spheres to adsorb thiomolybdate ion and calcine at high temperature.
Abstract: The invention provides an amorphous phase molybdenum trisulfide cathode material of a lithium sulfide battery and a preparation method thereof. Ammonium tetrathiomolybdate is added into deionized aqueous solution, PH is adjusted to acidity, porous carbon spheres are used for adsorption and evaporation drying solvent, the adsorbed carbon spheres are calcined in hydrogen/argon atmosphere, and annealed after calcination to obtain carbon-coated amorphous molybdenum trisulfide cathode material. The invention adopts porous hollow carbon sphere to adsorb thiomolybdate ion and calcine at high temperature, the thiomolybdate salt inside is converted into amorphous phase molybdenum trisulfide, in the process of recombination with lithium ions, S-S bond of amorphous phase molybdenum trisulfider ruptures to form short chain low sulfide and lithium composite which is not easy to dissolve in the electrolyte, thus reducing the shuttle of sulfide and overcoming the problem of cycle performance degradation caused by the large shuttle effect of the existing cathode materials of lithium-sulfide batteries.
3 citations
Patent•
20 Sep 2019
TL;DR: In this article, a super-hydrophilic super-gas-repelling transition metal molybdenum sulfur gel electrocatalyst is applied to water electrolysis. But the preparation method comprises following steps: impregnating an electrode carrier in an ammonium tetrathiomolybdate solution (0.05-0.2 mol/L) and a transition metal salt solution in sequence; then exposing the electrode carrier to the air in a still state; washing the electrode carriers; and drying.
Abstract: The invention relates to a preparation method of a super-hydrophilic super-gas-repelling transition metal molybdenum sulfur gel electrocatalyst. The preparation method comprises following steps: impregnating an electrode carrier in an ammonium tetrathiomolybdate solution (0.05-0.2 mol/L) and a transition metal salt solution in sequence; then exposing the electrode carrier to the air in a still state; washing the electrode carrier; and drying. The provided electrocatalyst can be applied to water electrolysis. According to the preparation method, a transition metal molybdenum sulfur gel catalyst is loaded on the electrode carrier; the catalyst is uniformly distributed on the surface of the electrode; the electrode then has a wrinkled multistage micro-nano structure and is amorphous; unsaturated sites and defects exist in the interior and surface of the catalyst; electro-catalysis for producing hydrogen and oxygen can be stably and efficiently performed; due to the super-hydrophilic and super-gas-repelling properties, the catalyst still has good and stable catalytic characteristics when the industrial current density is large; moreover, the operation of the preparation method is simple, the repeatability and the controllability are good, the equipment requirements are low at a room temperature under a normal pressure, the energy consumption is low, and the electrocatalyst is suitable for large scale industrial application.
2 citations
Patent•
19 Jul 2019
TL;DR: In this article, a preparation method and application of a bifunctional electrocatalyst of a molybdenum disulfide composite material is described, which belongs to the technical field of electrocatalysts.
Abstract: The invention discloses a preparation method and application of a bifunctional electrocatalyst of a molybdenum disulfide composite material, and belongs to the technical field of electrocatalysts. Thepreparation method comprises the following steps: preparing a precursor ZIF-8@ZIF-67 at first, carrying out carbonization to obtain C-N/Co, then adding C-N/Co, ammonium tetrathiomolybdate and hydrazine hydrate into N,N-dimethylformamide together, preliminarily preparing a molybdenum disulfide composite material through a solvothermal method, and finally, stabilizing molybdenum disulfide compositematerial by heat treatment to obtain a molybdenum disulfide composite material C-N/Co4S3@MoS2. The molybdenum disulfide composite material can be used in hydrogen evolution reactions or oxygen evolution reactions. The molybdenum disulfide composite material has strong conductivity, high atom utilization rate and excellent catalytic performance, and has the advantages of low cost, high efficiency,stability and the like.
2 citations
Patent•
22 Nov 2019
TL;DR: In this paper, a preparation method of a molybdenum disulfide/graphene/carbon composite material with a hierarchical pore structure is presented, which consists of the following steps: firstly preparing a polyacrylonitrile/polyvinylpyrrolidone/ammonium tetrathiomolybdate/ graphene composite nanofiber membrane by an electrostatic spinning method, and then decomposing polyvinylpolymorphic pore structures in the axial direction of the fiber, and meanwhile decomposing ammonium
Abstract: The invention discloses a preparation method of a molybdenum disulfide/graphene/carbon composite material with a hierarchical pore structure. The preparation method comprises the following steps: firstly preparing a polyacrylonitrile/polyvinylpyrrolidone/ammonium tetrathiomolybdate/graphene composite nanofiber membrane by an electrostatic spinning method; then decomposing polyvinylpyrrolidone at ahigh temperature to form a large number of mesoporous structures in the axial direction of the fiber, and meanwhile decomposing ammonium tetrathiomolybdate at a high temperature into single-layer molybdenum disulfide to be dispersed in the fiber; then soaking the product with a saturated KOH solution; and performing high-temperature activation to obtain the composite material. The composite material has the advantages of being high in specific surface area, developed in pore structure, controllable in pore size and structure, wide in application range and the like.
1 citations
Patent•
15 Nov 2019
TL;DR: In this article, a preparation method of an amorphous MoS2-modified CoS/Co0.85Se heterogeneous nanotube array electrocatalyst was described.
Abstract: The invention relates to a preparation method of an amorphous MoS2-modified CoS/Co0.85Se heterogeneous nanotube array electrocatalyst. The preparation method is characterized in that selenium powder (Se) used as a selenium source, ammonium tetrathiomolybdate ((NH4)2MoS4) used a molybdenum source and a sulfur source and a Co(CO3)0.5(OH) nanorod used as a self-sacrificial template undergo a solvothermal reaction to obtain the amorphous MoS2-modified CoS/Co0.85Se heterogeneous nanotube array. The diameter of the nanotubes of the amorphous MoS2-modified CoS/Co0.85Se heterogeneous nanotube array prepared in the invention is 30-60 nm. The amorphous MoS2-modified CoS/Co0.85Se heterogeneous nanotube array prepared in the invention exhibits an excellent electrocatalytic overall water-splitting performance, and the method of the invention has the characteristics of low cost, easiness in control, high uniformity and good repeatability.
1 citations
Patent•
13 Dec 2019
TL;DR: In this paper, a 3D porous cobalt-tin-molybdenum three-metal catalyst was proposed for hydrogen catalytic electrolysis under an acidic condition, which combines sulfide having high catalytic activity with oxide having good conductivity so synergistic effect among the compounds can be exerted, and the performance of the catalyst in all aspects is improved.
Abstract: The invention belongs to the technical field of inorganic nanomaterial preparation, and particularly relates to a preparation method of a 3D porous cobalt-tin-molybdenum three-metal catalyst. The preparation method comprises the following steps: dispersing a CoSn(OH)6 precursor and ammonium tetrathiomolybdate in water, and carrying out hydrothermal and calcining reactions to obtain the 3D porous cobalt-tin-molybdenum three-metal catalyst. The catalyst is of a porous cubic structure composed of cobalt disulfide, stannic oxide and molybdenum disulfide. The method disclosed by the invention is simple in synthesis and low in cost; and the prepared 3D porous cobalt-tin-molybdenum three-metal compound combines sulfide having high catalytic activity with oxide having good conductivity, so synergistic effect among the compounds can be exerted, and the performance of the catalyst in all aspects is improved. The catalyst has good application prospects when used as an electrode material for preparing hydrogen through catalytic electrolysis of water under an acidic condition.