21results about "Metal borides" patented technology

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 application provides a preparation method of high-purity superfine diboride powder and relates to the field of metal borides. The preparation method comprises the following steps: introducing BCl3 and H2 into a vacuum environment to obtain a mixed gas; mixing the mixed gas and metal wires and performing electric explosion treatment to obtain a reaction powder; and performing passivation ball milling treatment on the reaction powder in a mixed atmosphere of argon and oxygen to obtain the high-purity superfine diboride powder; and the metal wires comprise at least one of titanium wires, magnesium wires and aluminum wires. The method does not introduce by-products and impurities in the whole process, the obtained diboride powder is small in particle size, uniform in distribution and free of agglomeration, the preparation method is short in process and high in efficiency, and the method has a good industrialization prospect.

The application is a preparation method and application of ternary metal boride MoCoB electrocatalyst. 2 / 3 Y 1 / 3 )2AlB2 as a precursor, cobalt bromide as an etchant and a cobalt source, one-step removal of Al / Y and in-situ doping of Co to prepare MoCoB electrocatalyst with Mo / Co / B three-site synergy; Mo site efficiently adsorbs and activates nitrate, Co site dissociates water to provide active hydrogen, and B site builds an electronic bridge through orbital hybridization, thereby strengthening the electron transfer between active sites and the directional migration of active hydrogen. The electrocatalyst prepared by the application shows a faradaic efficiency of up to 61890 μg h ‑1 mg ‑1 and 98.73% in the reaction of nitrate reduction to synthesize ammonia, not only realizing high yield and high faradaic efficiency at the same time, but also showing the industrial application potential of green and sustainable synthesis of ammonia.

This invention relates to the field of hydrogen energy storage technology, specifically disclosing a layered transition metal boride-modified lithium-magnesium-boron-hydrogen composite hydrogen storage material and its preparation method. This material uses 2LiH+MgB2 as a matrix and adds layered Mo... 4 / 3 B2 MBene was prepared as a modifier; Mo was used as a modifier. 4 / 3 B2 MBene by (Mo 2 / 3 Y 1 / 3 The 2AlB2 MAB phase precursor was prepared by selectively etching with HF to remove Al and Y atoms, followed by intercalation, layering, and freeze-drying. This invention utilizes mechanical ball milling to process Mo... 4 / 3 B2 MBene introduces the Li-Mg-B-H (LMBH) composite system, utilizing Mo 4 / 3 The unique layered structure of B2 MBene, combined with its inherent catalytic activity, significantly reduces the hydrogen desorption temperature of the LMBH system and improves its hydrogen desorption kinetics and cycle stability. This material can release 8.1 wt% H2 within 60 minutes at 420℃, and maintains a capacity retention of 68.7% after three cycles. Its performance surpasses that of bulk MoB-doped and undoped LMBH systems, providing a new approach for performance regulation of lightweight hydrogen storage materials and demonstrating promising practical application prospects.

The application relates to the technical field of ultrahigh-temperature ceramic materials, and discloses a nano ZrB2-SiC composite ceramic powder based on gradient proportioning regulation and a low-temperature preparation method thereof; in view of the technical bottlenecks such as high reaction temperature (>=1600 DEG C), large powder particle size (>=10 mu m) and difficult two-phase proportion regulation in the prior art, the application innovatively proposes a gradient temperature-subsection proportioning preparation process. By accurately controlling the raw material proportioning of n(ZrO2):n(B4C):n(Si):n(C)=3:(1.8-2.0):1:(5.5-6.0), adopting a two-stage heating procedure (SiC crystal nuclei are preferentially generated at 1200 DEG C, and ZrB2 synthesis is completed at 1500 DEG C), the low-temperature and high-efficiency synthesis of ZrB2-SiC composite powder is realized in a single process. The complete reaction temperature is successfully reduced to 1500 DEG C, the average particle size of the obtained powder is 0.5-0.6 mu m, the oxygen content is <=0.8 wt%, and the ZrB2:SiC molar ratio can be accurately regulated in the range of 2:1 to 4:1 by adjusting the Si content. The ZrB2 (101) plane and the SiC (111) plane in the powder form a semi-coherent interface, and the crystal lattice distortion rate is <=3%.

The application provides a rare earth hexaboride submicron crystal or nanocrystal material and a preparation method thereof. 1‑ x RE x )B6 powder, La powder or RE powder, MeB2 powder is prepared through SPS sintering, the content of the La powder or RE powder is 1wt.%-5wt.%, the content of the MeB2 powder is 8wt.%-30wt.%, and the rest is (La 1‑x RE x )B6 powder, RE is Ce, Pr, Nd, Sm, Eu, Gd, Ca, S or Ba, Me is Ta, Cr, Nb, V, Hf, Ti or Zr, and 0 1‑x RE x )B6 submicron crystal is successfully obtained at a working temperature through SPS sintering in combination with La / RE sintering aids and MB2 powder with high melting point and high elastic modulus, and the thermal emission performance and mechanical properties of the material are improved.

The application discloses monodisperse rare earth boride nanomaterials with a size less than 20 nm, a preparation method and application thereof, and the phase state of the rare earth boride nanomaterials is REB6 or REB4; the preparation method comprises the following steps: S1, weighing compound raw materials containing RE elements and compound raw materials containing B elements respectively; S2, adding an additive and grinding thoroughly; S3, then performing a reaction under the protection of an inert gas; S4, after the reaction is completed, adding excessive methanol, performing centrifugal separation after no bubbles are generated, and reserving a precipitate A; S5, adding dilute hydrochloric acid for soaking, performing centrifugal separation again, and reserving a precipitate B; S6, washing the precipitate B with deionized water, drying, and obtaining the rare earth boride nanomaterials. The application adopts a normal-pressure low-temperature preparation method, and pure-phase rare earth hexaboride nanocrystals can be obtained at normal pressure and a temperature as low as 270 DEG C, and any active metal element is not needed to be introduced in the preparation process.

This provides a superconducting wire with high Tc and excellent flexibility. [Solution] A superconducting wire comprises a core material formed of a first material having superconducting properties, and a covering material formed of a second material different from the first material, which also has superconducting properties and covers the core material. In this superconducting wire, one of the first and second materials is MgB2, and the other of the first and second materials is a Cu oxide-based superconducting material.

This invention relates to the field of electrochemical-colorimetric analysis and detection technology, specifically to a bifunctional Ru / MoB MBene sensing probe, its preparation method, sensor, and applications. The key technical points are: mixing surface-modified Ru with a two-dimensional MoB MBene nanosheet suspension, and preparing a Ru / MoB MBene composite material via electrostatic self-assembly as a bifunctional sensing probe. This probe is used to construct an electrochemical-colorimetric dual-mode sensor, employing a dual-mode signal output strategy to fully leverage the advantages of electrochemical methods in terms of sensitivity, linear range, and precise quantification. It also integrates rapid colorimetric visualization and on-site screening capabilities. The two modes can operate independently or mutually verify each other, significantly improving the reliability of detection results, resistance to matrix interference, and practical applicability. This overcomes the problems of poor portability, long detection cycles, and insufficient sensitivity to trace micro / nanoplastics found in traditional equipment.

This invention belongs to the field of electromagnetic absorbing materials technology. It relates to a layered high-entropy MBene material, its preparation method, and its applications. This invention utilizes high-temperature Joule heating to prepare the layered high-entropy MBene material. This layered high-entropy MBene material possesses many significant advantages, such as abundant defect density, good conductivity loss, high specific surface area, a large number of exposed surface atoms, and excellent mechanical and electronic properties. It can effectively control electromagnetic parameters and achieve excellent electromagnetic absorption performance. Furthermore, it exhibits nanoscale effects, which can induce lattice distortion, defects, and microstrain, significantly optimizing impedance matching and enhancing dipole polarization and conductivity loss, thus demonstrating outstanding microwave absorption performance. The high-temperature Joule heating synthesis strategy proposed in this invention provides a new approach for the development of advanced high-entropy electromagnetic absorbing materials and offers a general method for the development of other layered materials with tunable structures.

Systems and methods for manufacturing ceramic powders are provided. In some embodiments, a method for forming a ceramic powder includes: adding a sufficient amount of an additive to a plurality of reagents to form a precursor mixture, such that when the precursor mixture is subjected to a carbothermal reaction, the precursor mixture forms a ceramic powder, wherein the additive comprises at least one of: an oxide, a salt, a pure metal, or an alloy of an element having an atomic number ranging from 21 to 30, 39 to 51, and 57 to 77, and combinations thereof; and subjecting the precursor mixture to a carbothermal reaction to form a ceramic powder, wherein the ceramic powder comprises: a) a morphology selected from the group consisting of: irregular, equiaxed, platy, and combinations thereof, and b) a particle size distribution selected from the group consisting of: fine, medium, coarse, and combinations thereof.

The application discloses a low-temperature preparation method of alkaline earth metal doped lanthanum hexaboride nano powder, relates to the technical field of inorganic functional material preparation, and comprises the following steps: S1, dehydrating lanthanum chloride heptahydrate and alkaline earth metal chloride hydrate by heating at 200-300 DEG C to obtain anhydrous mixed powder; S2, uniformly grinding the mixed powder after adding sodium borohydride to the mixed powder to obtain a boron-containing mixture; S3, mixing KCl / LiCl mixed molten salt with the boron-containing mixture for 25-40 hours to obtain a reaction precursor mixture; S4, placing the reaction precursor mixture in an inert atmosphere, heating to 900-1000 DEG C at a heating rate of 10-20 DEG C / min, and keeping the temperature for 0.5-1.5 hours to obtain a reaction product; and S5, dissolving, filtering, acid washing, water washing and drying the reaction product to obtain the alkaline earth metal doped lanthanum hexaboride nano powder. The alkaline earth metal doped lanthanum hexaboride nano powder prepared at a low temperature is single-phase, has a cubic morphology, and has uniform particle size distribution.

The present invention relates to a method (100) for obtaining supercapacitors in which the structure obtained by growing molybdenum boride (Mo2B), a member of the metal boride family, homogeneously, atomically thick and in crystalline form on a copper substrate by using chemical vapor deposition technique is used as an electrode, and to a supercapacitor obtained by the method (100).

The application provides a high-activity high-purity titanium boride powder for lithium ion battery energy storage and a preparation method thereof, and belongs to the technical field of titanium boride powder preparation. Through the conversion of iron oxide / nitrogen-doped carbon quantum dots into iron-based catalytic phases dispersed in the interface at high temperature and the provision of a high-activity carbon source, the conversion of titanium dioxide into titanium boride is facilitated and the generation of titanium carbide and free carbon is inhibited; the polyhydric alcohol-boric acid ester prepolymer serves as a dispersant and a coating layer, improves the mixing uniformity of titanium dioxide, boron carbide and other particles and supplements the boron source, and is converted into amorphous carbon and boron oxide glass phases after heating, thereby providing a local reduction and mass transfer channel and limiting the grain growth and hard agglomeration of titanium boride through the glass phase coating; through the synergy of double carbon sources and double boron sources and the catalysis-glass phase environment, fine titanium boride powder with good dispersity is obtained at a low reaction temperature, which can be used as a conductive ceramic component in a lithium ion battery energy storage electrode and can be used for energy storage battery related electrode coating materials.

The application discloses a preparation method of a recombinant collagen dressing and belongs to the technical field of medical dressings. The method comprises the following steps: preparing a hyaluronic acid aqueous solution and a collagen A solution, filtering and defoaming the two solutions respectively, and sterilizing the two solutions by high-temperature steam; filling the two solutions into different cavities of a mask bag respectively, and sealing the mask bag by nitrogen; placing C mixed solution and degradable non-woven fabric sterilized by high temperature and ultraviolet rays on a heating mold, and heating and evaporating the C mixed solution and the non-woven fabric to obtain a modified substrate with a surface wrinkle structure. The modified substrate is prepared by mixing the C mixed solution and the non-woven fabric, and the surface wrinkle structure is formed in the evaporation process, so that the tightness problem caused by solvent evaporation after the dressing is applied on the skin surface and the problem that the dressing components are broken to cause uneven application effect are effectively solved. The modified substrate can still maintain the surface wrinkle structure after being cyclically stretched and reset for 100 times, and the tensile strength retention rate reaches more than 95%, which proves the mechanical stability and durability of the wrinkle structure.

The application belongs to the technical field of functional composite materials, and relates to an electrochemical etching preparation method and application of Fe-based MBene two-dimensional material. The existing chemical etching technology has the problems of insufficient etching selectivity, severe reaction conditions and difficult regulation and control when preparing Fe-based MBene, which leads to defects such as oxidation of Fe element, residual Al layer, damage of Fe-B skeleton and collapse of two-dimensional morphology. Technical scheme: a three-electrode system is constructed by taking a conductive substrate loaded with Fe2AlB2 powder as a working electrode, a platinum sheet as a counter electrode and Ag / AgCl as a reference electrode; the three-electrode system is placed in a 70 DEG C, 15% to 20% sodium hydroxide solution, and electrochemical etching is carried out at a constant current density of 0.5 mA / cm2; after etching, the Fe-based MBene two-dimensional material is obtained through ultrasonic peeling in N-methyl pyrrolidone, magnetic separation, deionized water washing and freeze-drying.

The application belongs to the technical field of tungsten-rhenium alloy, and particularly relates to a tungsten-rhenium alloy wire and a preparation method thereof. The preparation method of the tungsten-rhenium alloy wire comprises the following steps: adding ammonium rhenate, rare earth nitrate, osmium-rhenium-boron compound and tungsten powder into water, stirring under heating conditions until a viscous paste is obtained, and obtaining a mixed powder after drying; pre-sintering the mixed powder under a hydrogen atmosphere, then roasting, and then performing spheroidization treatment to obtain a pre-alloy powder; performing static pressing on the pre-alloy powder, calcining the pre-alloy powder under a hydrogen atmosphere to obtain a sintered blank, then performing rotary swaging on the sintered blank, and then performing drawing, electrolytic cleaning and annealing to obtain the tungsten-rhenium alloy wire. The application simultaneously introduces the osmium-rhenium-boron compound and the medium and heavy rare earth elements into the tungsten-rhenium alloy matrix, and realizes the synergistic improvement of the normal-temperature mechanical property, high-temperature strength and oxidation resistance.

This invention provides a Pr6O 11 This invention relates to a core-shell structured ZrB2 / SiC composite powder, its preparation method and application, and a thermal protective coating, belonging to the field of anti-oxidation and corrosion-resistant coating technology. It also provides a Pr6O... 11 A core-shell structured ZrB2 / SiC composite powder, with ZrB2 / SiC powder as the core material and Pr6O as the outer shell. 11 The shell material is formed by coating rare earth Pr6O. 11 Modification of ZrB2 / SiC powder to form Pr6O 11 The core-shell structure can minimize the oxidation of ZrB2 / SiC powder during the spraying process, and also utilize Pr6O 11 The lower melting point allows for further filling of defects such as pores in the coating during the spraying process, improving the density of the coating and thus effectively enhancing the coating's ultra-high temperature oxidation and ablation resistance.

The present disclosure is a boron powder having two or more peaks in a number distribution, and having a ratio of a peak frequency of a peak having a second highest frequency, peak 2, to a peak frequency of a peak having a highest frequency, peak 1, of greater than 0.12. Preferably, a peak diameter of peak 1 is smaller than a peak diameter of peak 2.

This method for producing a metal boride comprises preparing: a first unheated raw material containing a metal source that is a metal, a metal oxide, a metal-containing carbonate or a metal-containing hydroxide, boron oxide or boric acid, silicon dioxide, and metallic sodium; or a second unheated raw material containing the metal source, boron oxide or boric acid, and silicon dioxide. Further, this method for producing a metal boride further comprises: heating the first unheated raw material if the first unheated raw material has been prepared; and heating the second unheated raw material in Na vapor if the second unheated raw material has been prepared.

The invention relates to the field of anion membrane water electrolysis hydrogen production, and discloses a boron-doped composite catalyst and a preparation method and application thereof, an oxygen evolution electrode and an electrolytic bath, the composite catalyst contains Fe, Ni, B and Co, and the molar ratio of Fe to Ni to B to Co is (0.1-1): (0.2-3): (1-3): 1. The composite catalyst has a two-dimensional layered structure, and boron is doped in a ternary metal compound catalyst of nickel, iron and cobalt, so that the valence state of Ni in an active center is improved, the alternating current resistance is reduced, and the oxidation activity and stability of the composite catalyst are improved.