206results about "Metal borides" patented technology

The invention discloses a rare earth boride nano material as well as a preparation method and application thereof. The phase state of the rare earth boride nano material is REB6 or REB4; the preparation method comprises the following steps: S1, respectively weighing a compound raw material containing an RE element and a compound raw material containing a B element; s2, adding an additive, and fully grinding; s3, reacting under the protection of inert gas; s4, after the reaction is finished, excessive methanol is added, centrifugal separation is performed after no bubbles emerge, and a precipitate A is reserved; s5, adding diluted hydrochloric acid for soaking, and performing centrifugal separation again to reserve a precipitate B; and S6, washing the precipitate B with deionized water, and drying to obtain the rare earth boride nano material. According to the preparation method disclosed by the invention, a normal-pressure and low-temperature preparation method is adopted, the pure-phase rare earth hexaboride nanocrystal can be obtained at normal pressure and the temperature as low as 300 DEG C, and no active metal elementary substance needs to be introduced in the preparation process.

The invention provides a preparation method of prismatic titanium diboride powder, and belongs to the technical field of titanium diboride powder. The preparation method comprises the steps of titanium source preparation, boron source preparation, material mixing, cold isostatic pressing and carbon thermal reduction reaction. The step of preparing the titanium source comprises the following steps: heating TiO2 powder body liquid, raising the temperature to 52-55 DEG C, adding a tetrabutyl titanate solution, uniformly stirring, adding an ammonia water solution to adjust the pH value to 7.0, and carrying out heat preservation stirring for 2.7-3.2 hours to obtain the titanium source; the step of preparing the boron source comprises the following steps: adding B4C powder into absolute ethyl alcohol, carrying out ultrasonic dispersion, then adding a mixed solution, controlling the adding rate of the mixed solution to be 0.8-1.2 g / min, heating to 34-37 DEG C, and carrying out heat preservation and stirring for 3.8-4.2 hours to obtain the boron source; the titanium diboride powder obtained through the method is in a prism shape and is uniform in particle, high in density and purity and poor in high-temperature oxidation resistance.

The invention belongs to the technical field of electrocatalysis, and particularly relates to a preparation method of a nickel-iron-based transition metal boride / black phosphorus composite oxygen evolution reaction electrocatalyst. The invention provides a preparation method of a ferronickel-based transition metal boride / black phosphorus composite oxygen evolution reaction electrocatalyst, which is characterized by comprising the following steps: synthesizing a quasi-two-dimensional ethylenediamine modified black phosphorus nanosheet (eda-BP) by a hydrothermal method, and carrying out ultrasonic treatment on the surface of the obtained eda-BP to obtain the ferronickel-based transition metal boride / black phosphorus composite oxygen evolution reaction electrocatalyst. The nickel-iron-based transition metal boride / black phosphorus composite oxygen evolution reaction (OER) electrocatalyst (Ni < x > FeyB / eda-BP) is prepared by loading nickel-iron-based transition metal boride (Ni < x > FeyB) through an in-situ chemical reduction method, so that modification of a two-dimensional black phosphorus electrocatalyst is realized; the problems of instability of a quasi-two-dimensional black phosphorus catalyst, serious Fe loss of a nickel-iron-based catalyst, poor reaction kinetics and the like are solved to a great extent, and under the synergistic effect of the two parts, the electro-catalytic oxygen evolution reaction activity and the electro-catalytic stability of the composite catalyst are remarkably improved. The preparation method of the nickel-iron-based transition metal boride / black phosphorus composite oxygen evolution reaction electrocatalyst provides a new thought and a new way for designing and developing a novel efficient and stable oxygen evolution reaction electrocatalyst.

The invention discloses application of a metal boride nano material in preparation of an immunosuppressant, and belongs to the technical field of biological medicine. Specifically, through a series of researches, it is found that the metal boride nano material catalyzes an organic substrate containing a-CH-OH group in cells, and meanwhile, NAD (P) < + > is converted to generate NAD (P) H, GSH rising is promoted, and cell reductive stress is initiated. The immune cells are further induced to differentiate to an immunosuppressive phenotype, secretion of immunosuppressive factors is promoted, secretion of immune activating factors is inhibited at the same time, and finally the immunosuppressive effect is achieved. The catalytic action of the substance can provide a lasting and stable immunosuppression effect, and the feasibility of the substance in initiation of reduction stress and immunosuppression is proved through in-vivo and in-vitro experiments. The invention provides a new immunosuppression strategy, which is expected to make up the defects of the traditional immunosuppressor, and provides a new choice for related treatment of clinical organ transplantation, autoimmune diseases, inflammatory diseases and the like.

The invention discloses medium-entropy MAB-phase ceramic powder and a preparation method thereof, and belongs to the technical field of ceramic material preparation. The chemical formula of the ceramic powder is (Cr1 / 3Mn1 / 3Fe1 / 3) 2AlB2, and the ceramic powder is structurally characterized in that three transition metal atoms of Cr, Mn and Fe are in random solid solution distribution at an M position. The preparation method of the material comprises the following steps: taking Cr powder, Mn powder, Fe powder, Al powder and B powder as raw materials, burdening according to a stoichiometric molar ratio in a chemical formula (Cr1 / 3Mn1 / 3Fe1 / 3) 2AlxB2 (wherein x is equal to 1.0-1.3), uniformly mixing, and sintering in a non-pressure tube furnace by adopting a two-stage heating sintering process. And crushing, drying and sieving the sintered product to obtain the ceramic powder. According to the invention, excessive aluminum powder is added to compensate high-temperature volatilization, and a two-stage sintering process is combined, so that the generation of an impurity phase is effectively inhibited, and a high-purity target product is successfully prepared. The synthesis method is simple in process, low in equipment requirement and suitable for large-scale production, and a material basis is provided for application of the medium-entropy MAB phase ceramic in the fields of electromagnetic functions, high-temperature environments and the like.

The invention discloses a TiB2 / SiO2 composite material and a preparation method thereof, and relates to the technical field of new materials.The preparation method of the TiB2 / SiO2 composite material comprises the following steps that TiB2 is pretreated with a NaOH solution, then Na2SiO3. 9H2O and deionized water are mixed and then added into the pretreatment solution, the pH is adjusted to be 8.5, stirring is conducted for 2 h at the temperature of 85 DEG C, and the TiB2 / SiO2 composite material is obtained; and sequentially carrying out centrifugal filtration, washing and drying to obtain the product. The TiB2 / SiO2 powder product is prepared through a specific chemical solution process, the TiB2 / SiO2 powder product has excellent dielectric properties and can be used for manufacturing wave-absorbing materials and reducing reflection of electromagnetic waves, and TiB2 and SiO2 both have excellent oxidation resistance, so that the TiB2 / SiO2 powder product prepared through the method has greater application potential at high temperature.

To provide a superconducting material that can be used for a liquid hydrogen level meter and that offers a simple manufacturing process and has reproducibility.SOLUTION: The superconductor comprises a metal compound having a molar ratio of magnesium (Mg) and boron (B) of 1:2, does not contain SiC, and has a critical temperature (Tc) of about 32 K to about 34 K at which electrical resistance becomes substantially zero. Thus, a liquid hydrogen level meter that offers a simple manufacturing process and has reproducibility can be realized.SELECTED DRAWING: Figure 1

The invention provides a lithium supplement agent, and belongs to the technical field of energy storage, the lithium supplement agent comprises lithium phosphite and a coating layer coating the surface of the lithium phosphite; and the material of the coating layer comprises iron boride. According to the invention, the problems of poor safety and stability, high cost, residues in the lithium supplementing process and the like of the lithium supplementing material in the related technology can be solved.

The invention relates to two dimensional (2D) heterostructures and methods of fabricating the same. The 2D hetero structures are integration of borophene with graphene and 2D lateral and vertical hetero structures with sharp and rotationally commensurate interfaces. The rich bonding configurations of boron indicate that borophene can be integrated into a diverse range of 2D heterostructures.

The present invention provides: a MgB2 superconducting wire that has a barrier layer of highly uniform thickness covering a MgB2 core and that reduces MgB2 filament defects and is suitable for thinning and lengthening; a MgB2 superconducting wire manufacturing method for manufacturing the same; a superconducting coil using the same; and a magnetic generator including the superconducting coil. A MgB2 superconducting wire (200) comprises: a core material (210); a MgB2 filament (220) in which a MgB2 core (221) is covered with a barrier layer (222); and a metal sheath (230). The MgB2 filament (220) has a barrier layer (222) thickness on the outer peripheral side of the wire not more than three times the barrier layer (222) thickness on the core side of the wire. The method for manufacturing the MgB2 superconducting wire includes a step for forming a single core wire, a step for forming an embedded material, a surface reduction processing step, and a heat treatment step. The embedded material is formed by arranging the single core wire in a recess formed in the outer surface of the core material or by incorporating a spacer in a gap.

The invention relates to a method for fabricating a two-dimensional (2D) heterostructure comprising depositing graphene on a substrate in an ultrahigh vacuum (UHV) chamber at a first temperature and a first chamber pressure to form sub-monolayer graphene on the substrate; and subsequently depositing borophene onto the sub-monolayer graphene on the substrate in the UHV chamber at a second temperature and a second chamber pressure so as to couple the borophene with the graphene on the substrate to form a 2D borophene-graphene heterostructure comprising lateral and / or vertical heterostructures.

The invention provides high-purity superfine titanium diboride and a preparation method thereof, and relates to the field of titanium diboride preparation. The method comprises the following steps: mixing boron oxide, titanium hydride, a carbon source, nano rare earth oxide and an organic solvent, and drying to obtain a mixture; in a vacuum environment, performing first roasting on the mixture to obtain a first roasted material; and in an oxygen-containing atmosphere, carrying out second roasting on the first roasting material to obtain the high-purity superfine titanium diboride. In the first roasting process, boron oxide, titanium hydride and a carbon source are completely melted and fully contacted, then further, the carbon source forms a carbon skeleton, the contact area between the melted boron oxide and titanium hydride and the carbon skeleton is further enlarged, liquid-liquid mixing and the increase of the contact area can reduce the reaction kinetic conditions, the reaction temperature is greatly reduced, and the reaction time is greatly shortened. The particle size of the generated titanium diboride is reduced, and the molten boron oxide and titanium hydride react on the porous carbon skeleton in a liquid-liquid form to generate the high-purity superfine titanium diboride.

The invention provides a high-compaction coated modified lithium manganese iron phosphate positive electrode material as well as a preparation method and application thereof, and relates to the field of lithium ion battery materials. The positive electrode material is prepared by the following steps: mixing a phosphorus source, an iron source, a manganese source, a magnesium source, a titanium source, a cobalt source, a lithium source, a carbon source and a dispersing agent, grinding, performing spray drying, and performing primary sintering to prepare a lithium manganese iron phosphate semi-finished product; the preparation method comprises the following steps: uniformly mixing a lithium manganese iron phosphate semi-finished product with tungsten boride, carrying out three-stage grinding including coarse grinding, coarse and fine grinding and fine grinding, carrying out batch mixing on the ground reduced slurry according to different volume ratios to improve the compaction density of the material, uniformly mixing the slurry, carrying out spray drying, and carrying out high-temperature sintering to obtain the lithium manganese iron phosphate composite material. And carrying out airflow crushing and sieving to obtain the high-compaction coated and modified lithium manganese iron phosphate positive electrode material. After tungsten boride and lithium manganese iron phosphate are coated, chemical acting force is formed on the surface, the polarization phenomenon is remarkably weakened, and the positive electrode material shows good long-term cycle stability.

The invention discloses a lithium ion battery ultrahigh nickel positive electrode material and a preparation method and application thereof, and belongs to the technical field of lithium ion batteries. The ultrahigh nickel positive electrode material is formed by coating the surface of a boron-doped nickel cobalt lithium manganate positive electrode material with a hydrophobic transition metal diboride. The surface of the ultra-high nickel active material is coated with the thin and uniform transition metal diboride hydrophobic coating layer, transition metal diboride has high ionic conductivity, and the obtained lithium ion battery has good cycle performance; the transition metal diboride can ensure the hydrophobic property, so that the stability of the lithium ion battery in the environment is ensured; the surface transition metal diboride and internally doped boron ions are synergistically modified, so that the cycle performance, the rate capability and the safety performance of the material in battery application are remarkably improved.

The invention discloses a zirconium boride-carbon hybrid aerogel composite material and a preparation method thereof, and belongs to the technical field of aerogel materials. In order to solve the problem of insufficient oxidation resistance of a carbon aerogel material, a co-gel method is mainly adopted to introduce a zirconium boride precursor network, zirconium boride is generated in situ through pyrolysis reduction, and matrix oxidation resistance modification of carbon aerogel is realized. A stable anti-oxidation protection layer can be formed in a high-temperature aerobic environment, the high-temperature-resistant and anti-oxidation performance of the material is improved, and the material can be applied to the field of light thermal protection.

The invention belongs to the technical field of preparation of alkaline earth metal hexaboride powder, and provides a preparation method of strontium hexaboride nanopowder, which comprises the following steps: drying SrCl2. 6H2O powder to obtain SrCl2 powder; the preparation method comprises the following steps: grinding and mixing SrCl2 powder and NaBH4 powder to obtain mixed powder a; the mixed powder a and LiCl-KCl eutectic salt are mixed, and mixed powder b is obtained; performing high-temperature reaction on the mixed powder b to obtain mixed powder c; and dissolving the mixed powder c in water, and sequentially filtering, drying, pickling and washing to obtain the strontium hexaboride nano powder. The average particle size of the prepared nano powder is 30-80 nm, and the nano powder has good cubic morphology, has the characteristics of high surface activity, large specific area and the like, and has wide application prospects as multifunctional ceramic powder. Meanwhile, the preparation cost can be effectively reduced, and a new thought for preparing the SrB6 powder is provided.

The invention discloses a high-rate high-nickel cobalt-free positive electrode material and a preparation method and application thereof, the chemical formula of the positive electrode material is LiNi < x > Mn < 1-x-y-z > M < y > N < z > O < 2 >, M is one or more of Al, Zr, Y, W, Nb, Ce, Ti, Mg, Sr, B, P or Si, and N is an MBene material coating layer, 0.5 lt; xlt; 1.0, 0 lt; yt; Yt; 0.1, 0 lt; zlt, zlt; 0.1, 0 lt; x + y + zlt; the preparation method comprises the following steps: 1, selecting a porous precursor, carrying out lithium matching and sintering to obtain a positive electrode material matrix, polishing the positive electrode material matrix, separating out a polishing agent and fine powder generated by polishing, coating an MBene material, and annealing and sintering to obtain the high-nickel cobalt-free positive electrode material with a porous structure inside and a coating layer with stable chemical properties and high conductivity on the surface; when the composite material is used for a lithium ion battery, the pulping viscosity change is small, the rate capability is good, and the cycling stability is remarkably improved.

The invention provides a lithium manganese iron phosphate positive electrode material, a preparation method thereof and a lithium ion battery, and relates to the field of secondary batteries. The lithium manganese iron phosphate positive electrode material comprises an inner core and a coating layer located on the outer surface of the inner core, a material for forming the inner core comprises lithium manganese iron phosphate, a material for forming the coating layer comprises a high-conductivity compound, the high-conductivity compound comprises manganese and a non-metallic element, and the non-metallic element comprises any one of B, S, P, Si, As and Se. The coating layer containing the high-conductivity compound is formed on the outer surface of the lithium manganese iron phosphate, so that the resistivity of the material can be reduced, the dissolution of the manganese element in the lithium manganese iron phosphate can be inhibited, and the cycle performance of the material can be improved.

To provide a superconducting material that can be used for a liquid hydrogen level meter and that offers a simple manufacturing process and has reproducibility.SOLUTION: The superconductor comprises a metal compound having a molar ratio of magnesium (Mg) and boron (B) of 1:2, does not contain SiC, and has a critical temperature (Tc) of about 32 K to about 34 K at which electrical resistance becomes substantially zero. Thus, a liquid hydrogen level meter that offers a simple manufacturing process and has reproducibility can be realized.SELECTED DRAWING: Figure 1

The present invention discloses an in-plane ordered multi-component MAX phase material and MXene material and a preparation method and use thereof, wherein the chemical formula of the multi-component MAX phase material is expressed as (M x 'M" y ) n+1 AX n , wherein n is between 1 and 6, x+y=1, M' and M" are arranged in order in at least one crystal plane; the sum of the element types of M' and M" is at least three; wherein M' is selected from at least one or two elements of IVB, VB, VIB, VIIB, VIII, IB and IIB groups, and M" is selected from at least one or two elements of IIIB group, zirconium, lanthanide and actinide. By etching component A in the MAX phase material, an in-plane ordered multi-component MXene material is obtained. Due to its ordered structure and multi-component atomic composition, it belongs to a new type of super surface; further selectively etching the atoms in the in-plane ordered multi-component MXene material can obtain an ordered vacancy or multi-vacancy MXene material, which also belongs to a new type of super surface. It has application prospects in anti-corrosion coatings, high-temperature coatings, nuclear radiation protection, catalysis, and other fields.

Provided are methods of producing cobalt-based nanoparticles (CoxBy NPs) of a pre-selected diameter. The methods include reducing Co2+ ions with a sodium borohydride (NaBH4) solution having a selected ratio of tetrahydroxyborate (B(OH)4−) to tetrahydroborate (BH4−) based on the pre-selected diameter, where the ratio of B(OH)4− to BH4− is positively correlated with the pre-selected diameter. Also provided are methods of using the CoxBy NPs to produce hollow metal nanospheres (HMNs). Methods of producing CoxBy NP core / metal shell structures are also provided, such methods including combining in an anaerobic galvanic exchange reaction a deaerated solution including CoxBy NP scaffolds and a deaerated solution including a metal. Also provided are methods of producing HMNs from the CoxBy NP core / metal shell structures. Compositions and kits that find use in practicing the methods of the present disclosure and using HMNs produced in accordance with the methods of the present disclosure, are also provided.

The invention belongs to the technical field of preparation of high-purity cobalt boride, and particularly provides a preparation method of high-purity superfine cobalt boride powder, which comprises the following steps: 1) mixing Co3O4 with isopropanol, sanding and crushing to obtain Co3O4 slurry; b4C and isopropanol are mixed, sanded and crushed to obtain B4C slurry; then mixing the Co3O4 slurry with the B4C slurry and carbon black at a high speed to obtain a mixture; 2) sintering the mixture under the protection of inert gas to obtain a sintered material, and 3) scattering and sieving the sintered material to obtain the CoB. The CoB prepared by the invention has the advantages of low impurity content, small particle size and uniformity.

The invention relates to the field of batteries, and provides a preparation method and application of an electrode material aiming at the problem that strong acid and strong alkali dangerous solutions need to be used for preparing the electrode material MBenes. The preparation method comprises the following steps: dispersing transition metal boride powder in a solvent, and sequentially performing primary centrifugation, freezing and thawing, secondary centrifugation and drying to obtain the two-dimensional transition metal boride nanosheet MBenes. The transition metal boride powder is cracked into a special nanostructure by using simple mechanical means (stirring-centrifuging-freezing), and the preparation process is simple and harmless to the environment. The prepared electrode material can be applied to a lithium battery, a sodium battery, a potassium battery, an aluminum battery, a zinc battery, a magnesium battery, a fuel battery, a super capacitor or a solar battery.

The invention discloses a diboride hollow microsphere and a preparation method thereof, and belongs to the technical field of new material preparation. The invention aims to solve the problem of preparing diboride hollow microspheres with excellent performance. The preparation method comprises the following steps: preparing precursor sol; performing gelatinization treatment on the precursor sol in a high-temperature closed environment, performing normal-pressure drying in an open environment to obtain a diboride hollow microsphere precursor, grinding the diboride hollow microsphere precursor into powder in a crucible, then performing secondary grinding in an aqueous solution containing PEG-4000, performing ultrasonic treatment after uniform grinding, and then performing vacuum drying to obtain the diboride hollow microsphere. And carrying out high-temperature boron-carbon thermal reduction reaction on the obtained diboride hollow microsphere precursor to generate diboride hollow microspheres, and carrying out solution treatment on the diboride hollow microspheres under a high-temperature condition to obtain a final product. The preparation of the high-quality diboride hollow microspheres is realized, the high-quality diboride hollow microspheres have good dispersity, and the product forming rate can reach 80% or above.

The invention belongs to the technical field of photocatalyst composite materials, and particularly relates to a covalent bond bonded MoBTx / CdS composite material and a preparation method and application thereof.According to the MoBTx / CdS composite material, rod-shaped CdS and two-dimensional layered MoBTx are compounded through an in-situ growth strategy, covalent bonding between Mo atoms and S atoms is achieved at an interface, and the MoBTx / CdS composite material is obtained. Therefore, a strong-coupling heterogeneous interface is constructed. The covalent bond mediated composite structure can significantly enhance visible light absorption and optimize carrier separation and transmission kinetics, thereby improving the activity and stability of hydrogen production by photocatalytic decomposition of water. The material is excellent in environmental adaptability and can keep good hydrogen evolution performance under complex water quality and low-temperature conditions. The research provides a new interface engineering idea for designing an efficient and stable semiconductor-metal boride photocatalyst.

Provided is a method for preparing zirconium boride through electric smelting. The method includes: mixing a zirconium source, boric anhydride, and a carbon source to obtain a furnace charge; conducting a smelting by feeding the furnace charge into a three-phase electric arc furnace and melting, subjecting a resulting material to refinement, heat preservation, and homogenization in sequence; heat preserving a resulting product for 1 hour to 2 hours after the smelting, and turning off the three-phase electric arc furnace; removing a resulting furnace shell and natural cooling a resulting melt; and crushing the resulting melt, selecting and removing a material skin; crushing a resulting selected material and selecting again, and removing a loose lump and collecting a dense lumpy material; and crushing the dense lumpy material, and then testing to qualify as a finished product.

The present invention relates to a method for dissolving atoms in a metal, and provides a method for easily dissolving atoms in a metal having low solubility for the atoms by using, as a mediator, a metal which has high solubility for the atoms. Thus, elements such as carbon (C), boron (B), and nitrogen (N) can be stably introduced into metals in which these elements cannot be dissolved by using existing techniques or have very low solubility, thereby enabling the synthesis of new compounds and doped metals or alloys, resulting in improved physical properties of a metal, for example, properties such as strength, corrosion resistance, and conductivity.

[Problem] The present invention addresses the problem in realizing a superconducting material which can be used for a liquid level gauge for liquid hydrogen, enabling a simple production method, and achieving reproducibility. [Solution] The present invention provides a superconductor which is composed of a metal compound that has a molar ratio of magnesium (Mg) to boron (B) of 1:2, and does not contain SiC. This superconductor is characterized in that the critical temperature (Tc) thereof, at which the electric resistance is substantially zero, is about 32K to about 34K.　As a result, it is possible to realize a liquid level gauge for liquid hydrogen, which enables a simple production method and achieving reproducibility.

The invention relates to the technical field of thermoelectric materials, and discloses an Mg3Bi2-based thermoelectric material and a preparation method thereof. The method comprises the following steps: selecting a magnesium-containing raw material with relatively high (002) peak intensity as a magnesium raw material; weighing the magnesium raw material and bismuth according to a stoichiometric proportion, mixing the magnesium raw material and the bismuth, and carrying out ball milling to obtain mixed powder; and sintering the mixed powder to obtain the Mg3Bi2-based thermoelectric material. According to the preparation method provided by the invention, the Mg3Bi2-based thermoelectric material preferentially oriented in the (002) direction is prepared by taking an Mg metal raw material preferentially oriented in the (002) direction as a template and combining mechanical alloying and sintering technologies, and the magnetic resistance of the obtained thermoelectric material is 3342-5089% at the temperature of 2K and in a magnetic field of 14Tesla. The method is expected to provide a reference idea for preparation of preferred orientation structures of other Mg-based compounds. Wide application prospects are realized in the fields of energy recovery, waste heat utilization and the like. In an industrial waste heat recovery system, waste heat can be efficiently converted into electric energy, and energy waste is reduced.

The present disclosure relates to a boron powder having two or more peaks in a number distribution, and a peak frequency of a peak 2 having the second highest frequency relative to a peak frequency of a peak 1 having the highest frequency is more than 0.12. It is preferable that the peak diameter of the peak 1 is smaller than the peak diameter of the peak 2.