37results about How to "Synthesis temperature is low" patented technology

The invention discloses nanoscale high-entropy A2B2O7 type oxide ceramic powder and a preparation method of a nano ceramic block of the nanoscale high-entropy A2B2O7 type oxide ceramic powder, and the preparation method comprises the following steps: S1, uniformly dispersing a rare earth element source and a transition metal source in deionized water, stirring at room temperature, and then adding a polymerizing agent and an inducer to obtain a mixed solution; s2, continuously stirring at room temperature to form a transparent clear solution; s3, heating the transparent clarified solution until milk white gel is gradually formed; and S4, drying the milk white gel into dry gel. According to the nanoscale high-entropy A2B2O7 type oxide ceramic powder and the preparation method of the nano ceramic block of the nanoscale high-entropy A2B2O7 type oxide ceramic powder, discharge plasma sintering is combined with a two-step preparation process, the efficiency is high, sintering is compact, the grain size of a ceramic block material can be controlled, and the nano ceramic block can be used for preparing the nano-scale high-entropy A2B2O7 type oxide ceramic powder. And the synthesized oxide has the characteristics of fine powder particle size, uniform distribution, few impurities and the like, and the method is low in synthesis temperature and relatively low in cost.

The invention discloses a lithium zirconate material and a preparation method and application thereof. The preparation method comprises: weighing a lithium source material and a zirconium source material according to a stoichiometric ratio, placing the materials in a high-speed mixer, adding a sintering aid and mixing the materials uniformly to obtain a mixed material; subjecting the mixed material to a crystallization treatment, wherein the crystallization temperature is 750°C to 900°C and the crystallization time is 5 hours to 15 hours to obtain a precursor material; subjecting the precursor material to a crushing treatment to obtain a lithium zirconate material; wherein the particle size Dv50 of the zirconium source material is between 0.5 μm and 3 μm; the sintering aid is a fluoride; the rotation speed of the high-speed mixer is between 2000 rpm and 3500 rpm, and the mixing time is 5 min to 30 min.

The invention is applicable to the technical field of luminescent materials, and provides a long-wavelength ultra-wideband sulfide near-infrared luminescent material and a preparation method and application thereof, the general chemical formula of the luminescent material is Ca < 1-x > CrxS, and x is more than or equal to 0 and less than or equal to 0.125%; the preparation method comprises the following steps that raw materials are weighed according to the chemical general formula Ca < 1-x > CrxS and the molar ratio of Ca to Cr in the raw materials being 1-x: x, x is larger than or equal to 0 and smaller than or equal to 0.125%, and the raw materials are compounds containing Ca and Cr elements; the preparation method comprises the following steps: weighing raw materials, adding a dispersing agent into the weighed raw materials, fully grinding to obtain uniform white powder, pre-sintering the ground white powder at 700-800 DEG C for 2-3 hours, introducing vulcanizing gas, and sintering in a vulcanizing environment at 800-900 DEG C for 2-3 hours to obtain the long-wavelength ultra-wideband sulfide near-infrared luminescent material. The luminescent material provided by the invention is excellent in performance, can effectively meet the requirements of near-infrared LED devices, and is widely applied to the fields of modern food quality analysis, biological imaging, biomedicine and the like.

The application belongs to the technical field of comprehensive utilization of waste lithium-ion power battery, and discloses a deep eutectic lithium supplement and a method for repairing and regenerating positive electrode material of waste lithium-ion battery, wherein the deep eutectic lithium supplement is prepared by taking a solid-state reducing organic acid as a hydrogen bond donor and a solid-state lithium source as a hydrogen bond acceptor, mixing the hydrogen bond donor and the hydrogen bond acceptor, and reacting to obtain a deep eutectic melting state system; and the deep eutectic lithium supplement can be used for repairing and regenerating the positive electrode material of the waste lithium-ion battery. The application can prepare a liquid-state deep eutectic lithium supplement by using a solid-state reducing acid and a solid-state lithium source, is green and friendly, can realize self-limiting lithium supplement without strict control of the lithium supplement amount, has low energy consumption in the lithium supplement process, can greatly reduce the cost, and can be used for repairing and regenerating the positive electrode material of the waste lithium-ion battery.

The application provides a preparation method of a composite molecular sieve and application of the composite molecular sieve in heavy oil cracking, and the preparation method comprises the following steps: dissolving an aluminum source, a silicon source and a structure directing agent in water, and then performing crystallization treatment to obtain a ZSM-5 crystal seed solution; etching Y type molecular sieve in water by using an alkaline substance to form a hollow structure, and then mixing the hollow Y type molecular sieve with acidic silica sol to obtain a solution containing the hollow Y type molecular sieve; mixing the ZSM-5 crystal seed solution and the solution containing the hollow Y type molecular sieve, and then performing temperature crystallization, and then separating a crystallization product, and then performing washing, drying and calcination to obtain a ZSM-5 / Y composite molecular sieve, and then performing ion exchange reaction, and then performing calcination to obtain a H type ZSM-5 / Y composite molecular sieve product. The composite molecular sieve synthesized by the application has the advantages of high activity, good selectivity and the like when the composite molecular sieve is prepared into a catalyst, high liquefied gas and propylene yield can be obtained, and the composite molecular sieve is particularly suitable for the field of petrochemical catalytic cracking.

The application discloses high-entropy rare earth silicate ceramic nano powder and a preparation method and application thereof. The preparation method of the high-entropy rare earth silicate ceramic nano powder comprises the following steps: 1) dissolving rare earth oxide powder in an acid solution to prepare a rare earth salt solution; 2) mixing the rare earth salt solution and a sodium silicate solution, adding ammonia water to perform chemical co-precipitation, then performing standing and aging, and then taking the precipitate to perform drying to obtain a precursor powder; and 3) placing the precursor powder under the condition that the temperature is 1100 DEG C to 1200 DEG C to perform calcination. The high-entropy rare earth silicate ceramic nano powder has excellent characteristics such as small particle size, uniform element distribution, large component space and no impurity phase, and the preparation method has the advantages of low synthesis temperature, simple equipment, simple and controllable process, low industrialization cost and the like, is suitable for being used on a hot end part of an aerospace engine and has a very wide application prospect.

The invention provides a preparation method of sodium pyrrolidone carboxylate, and belongs to the technical field of chemical synthesis. The preparation method of the sodium pyrrolidone carboxylate comprises the following steps: 1) mixing sodium glutamate, ultrapure water and a catalyst, and adjusting the pH value to weak acidity to obtain a mixed solution; and 2) transferring the mixed solution into a micro-channel reactor, and reacting to obtain the sodium pyrrolidone carboxylate. The sodium pyrrolidone carboxylate prepared by the method provided by the invention is high in yield and purity, and the preparation method is simple and efficient.

The invention relates to a low-carbon high-belite / high-iron phase mineral material as well as a preparation method and application thereof, and the low-carbon high-belite / high-iron phase mineral material comprises the following raw materials in parts by mass: 90-110 parts of a calcium raw material, 0-26 parts of a siliceous raw material, 2-29 parts of an aluminum raw material, 7-45 parts of an iron raw material and 1-5 parts of a sintering additive. A calcium raw material, a siliceous raw material, an aluminum raw material and an iron raw material are used as main raw materials, the low-carbon high-belite / high-iron phase mineral material is generated by regulating and controlling the proportion of the raw materials and under the action of a firing additive, the content of belite and iron phase in the mineral material is high, and the mineral material also contains part of alpha '-type dicalcium silicate with high gelation activity; the cement admixture can be used as a cement admixture to be combined with cement clinker to grind cement or be used as an admixture to be directly added into concrete, so that the high compressive strength of the concrete is maintained, the hydration heat release is reduced, the crack resistance is improved, and the chloride ion penetration resistance is enhanced.

This invention discloses a method for preparing high-entropy ceramic matrix composites using a reactive infiltration process, belonging to the technical field of ceramic matrix composites. The steps are as follows: at least four single-component carbides are ball-milled and mixed with a carbon source, then dispersed in a dispersion liquid to obtain a slurry; continuous fibers are woven into a preform, and an interface layer and a matrix layer are deposited to obtain a semi-dense composite material; the slurry is introduced through vacuum or pressure impregnation; and a high-entropy carbide matrix is ​​generated in situ and densified by reactive infiltration after embedding with a transition metal and its alloy. This invention solves the problems of long process cycles, high porosity, high cost, and insufficient introduction of high-entropy ceramics in existing processes, achieving rapid densification and improving the material's high-temperature stability, oxidation resistance, and ablation resistance. It is suitable for the large-scale production of thermal protection materials for hypersonic vehicles.

The invention relates to a carbon quantum dot fluorescent material synthesized by efficient catalysis of cuprous oxide and a preparation method of the carbon quantum dot fluorescent material, and provides a synthesis method for preparing a bright carbon quantum dot fluorescent material by efficient catalysis of a dehydration decomposition reaction of isopropanol and organic amine by taking a Cu2O colloidal solution simultaneously synthesized by a one-step method as a catalyst. Copper salts such as copper chloride and copper acetate are used as starting raw materials of catalysts, isopropanol is used as a carbon source and a solvent, and organic amines such as ethylenediamine, o-phenylenediamine and 2, 3-diaminonaphthalene are used as nitrogen sources and organic alkali. Cu < 2 + > is hydrolyzed into a Cu (OH) 2 colloidal solution under the action of organic alkali; the Cu (OH) 2 colloidal solution is reduced into a Cu2O colloidal solution by glucose at a certain temperature; the Cu2O colloidal solution efficiently catalyzes the dehydration decomposition reaction of isopropanol and organic amine to synthesize the bright fluorescent carbon quantum dot material. According to the synthesis method, the reaction temperature and time for synthesizing the carbon quantum dots by a solvothermal method are greatly reduced. The method provided by the invention is an efficient, green and environment-friendly preparation method for synthesizing carbon quantum dot fluorescent materials with various colors.

The present invention discloses a chemical vapor deposition device for preparing particle products, wherein a cylinder is vertically arranged in the inner cavity of a chemical vapor deposition furnace, the upper end of the cylinder abuts against the upper cover, and the lower end abuts against the lower cover; at least three supporting rings are arranged on the inner wall of the cylinder; at least three porous plates are arranged in the cylinder; the porous plates have a plurality of through holes, and the edges of the porous plates are placed on the supporting rings; a plurality of nozzles are arranged between two adjacent porous plates, a plurality of perforations are arranged on the side walls of the nozzles, the lower end of the nozzle abuts against the porous plate below, and the upper end of the nozzle abuts against the porous plate above; the through holes of the porous plate below all correspond to the inner cavities of the plurality of nozzles, and the through holes of the porous plate above all correspond to the gaps between the plurality of nozzles. The present invention guides and controls the flow path of the reaction gas, thereby realizing the growth of high-purity silicon carbide powder in the raw material atmosphere through chemical vapor deposition, and can realize the preparation of large-particle-size, high-purity particles.

The invention relates to gadolinium oxysulfide powder based on a molten salt method and a preparation method of the gadolinium oxysulfide powder. The preparation method specifically comprises the following steps: preparing a precursor solution, and cleaning and drying an obtained precipitation product to obtain precursor powder; the precursor powder is one of Gd2O2CO3, Gd2 (SO4) 3.8 H2O, Gd2 (OH) 4SO4. XH2O and Gd2 (OH) 5NO3. XH2O, and the precursor powder is one of Gd2O2CO3, Gd2 (SO4) 3.8 H2O, Gd2 (OH) 4SO4. XH2O and Gd2 (OH) 5NO3. XH2O; uniformly mixing the prepared precursor powder, a sulfur source and fused salt, putting the mixture into a crucible, sintering at high temperature in a protective atmosphere to enable the mixed powder to form a molten state, and cleaning and drying after sintering and cooling to obtain gadolinium oxysulfide powder; and the molten salt is one of Li2CO3 and Na2CO3, Li2CO3 and K2CO3, Li2CO3 and K2CO3, and Na2CO3. The invention also discloses a preparation method of the lithium ion battery. Compared with the prior art, the method has the advantages that the Gd2O2S powder is synthesized in the air or the reducing atmosphere or the inert atmosphere, compared with a traditional high-temperature solid-phase synthesis method, the synthesis temperature is greatly reduced, and the generated Gd2O2S is good in crystallinity, high in purity, free of impurity phases and high in dispersity.

The invention provides a glass substrate, a preparation method thereof and an electronic device. The glass substrate comprises a bottom layer, a top layer, a glass plate lamination layer and a glass bonding lamination layer. The glass plate lamination layer comprises m glass plate single layers, and the glass bonding lamination layer comprises m + 1 glass bonding single layers. The melting point of the glass bonding single layer is lower than that of the glass plate single layer. The glass bonding single layer comprises 70-85% of glass powder and an organic bonding agent. The glass powder is prepared by adopting special process steps. The glass bonding single layer is low in melting point, low in glass transition point and high in uniformity, the raw materials are low in price and rich in source, the synthesis temperature is low, the process is simple, and industrial production is facilitated. The glass bonding single layer has a lower thermal expansion coefficient, higher strength and better chemical stability and thermal stability, has very high bonding force with high borosilicate glass and microcrystalline glass, and has good insulativity and higher safety.

This invention provides a method for preparing cubic phase zirconia nanoparticles based on the complexation confinement effect. Step 1 involves weighing ZrOCl2·8H2O, YCl3, and (C6H) 10 O5) n Step 1: Add deionized water to a beaker and stir until completely dissolved to obtain a mixed solution; Step 2: Weigh EDTA-2Na·2H2O into a beaker, add deionized water, and stir until completely dissolved; Step 3: Add the solution obtained in Step 2 to the solution obtained in Step 1, heat and stir in a water bath to obtain a zirconia precursor solution; Step 4: After centrifuging and washing the zirconia precursor solution, dry it in an oven and grind it to obtain zirconia precursor powder; Step 5: Place the zirconia precursor powder in a muffle furnace and calcine it at high temperature in air to obtain cubic phase nano-zirconia powder. This method is simple and easy to implement, and can be easily scaled up for industrial production. The product has high purity and can be used in SOFC and oxygen sensors, etc.

A preparation method and application of a titanium niobate / titanium tantalate / tungsten niobium oxide three-phase heterojunction material, belonging to the field of secondary batteries, uses a high-temperature solid phase method to first synthesize a titanium niobate material, and then evenly mixes the tantalum source, titanium source, niobium source, and tungsten source required for preparing the titanium tantalate and tungsten niobium oxide materials to obtain a precursor, and evenly mixes the precursor with the synthesized titanium niobate material, and sinters in a tubular furnace to generate a titanium niobate / titanium tantalate / tungsten niobium oxide three-phase heterojunction material. The present invention prepares a titanium niobate / titanium tantalate / tungsten niobium oxide three-phase heterojunction material for the first time, utilizes the unique advantages of the heterojunction material interface, and generates electronic structure complementarity and energy band rearrangement, combined with the built-in electric field effect of the heterojunction, significantly improves the electronic conductivity and ionic conductivity of the titanium niobate material, and improves its discharge capacity, high rate performance, long cycle life and other electrochemical properties in low-temperature batteries.

The invention discloses preparation and application of a molybdenite / ZnO nanorod with a pillared structure, and belongs to the technical field of gas sensing. The preparation method comprises the following specific steps: (1) dispersing commercially available molybdenite into a zinc acetate methanol solution to obtain a solution A; (2) adding a sodium hydroxide methanol solution into the solution A to obtain molybdenite / ZnO nanoparticles; (3), the molybdenite / ZnO nano particles are dispersed into deionized water, and molybdenite / ZnO nano particle suspension liquid is obtained; and (4) adding the molybdenite / ZnO nano-particle suspension into a sodium hydroxide solution of epsilon-Zn (OH) 2, heating, aging, stirring, washing, and drying overnight to obtain the molybdenite / ZnO nano-rod with the heterogeneous pillared structure. The gas sensitive material disclosed by the invention has the characteristics of simple preparation method, low cost and the like, and has relatively good response performance to ppb-grade NO2.

The invention provides a method for preparing high-crystallinity modified carbon nitride at low temperature, and belongs to the technical field of photocatalytic materials.The method comprises the steps that urea, solar salt and phosphonyl chloride tripolymer are mixed and then ground, and a mixture is obtained; calcining the mixture at the temperature of 300 to 400 DEG C to obtain a calcined product; performing washing and vacuum drying on the calcined product to obtain high-crystallinity modified carbon nitride; wherein in the mixture, the mass ratio of the urea to the solar salt to the phosphonyl chloride tripolymer is 20: 4: 1. The modified carbon nitride prepared by the method has the advantages of wide spectral response and high carrier separation efficiency, so that the modified carbon nitride has excellent photocatalytic performance, the synthesis temperature of the modified carbon nitride in the method is relatively low, and the modified carbon nitride has the advantages of low energy consumption and low cost. The invention also provides high-crystallinity modified carbon nitride and application thereof.

This invention relates to a method for preparing Co-based oxide nanosheets based on the oxygen vacancy-regulated reaction mechanism and their application in acidic oxygen evolution reaction (OER). The aim is to address the issue of insufficient efficiency in the electrocatalytic OER. The preparation method includes: 1. Ultrasonic cleaning of carbon cloth; 2. Electrodeposition of cobalt hydroxide precursor using a cobalt salt solution as the electrolyte and the cleaned carbon cloth as the working electrode; 3. Immersion of the cobalt hydroxide precursor in sodium borohydride solution; 4. Electrodeposition of the precursor with oxygen vacancies as the working electrode, a carbon rod as the counter electrode, and a ruthenium metal salt solution as the electrolyte; 5. High-temperature annealing at 400-500°C. The Co-based oxide nanosheets prepared by this invention successfully trigger the LOM mechanism, improving the utilization rate of the precious metal ruthenium, reducing the amount of ruthenium used, and significantly enhancing the catalytic activity and stability of the acidic OER compared to Co3O4.

The invention belongs to the technical field of fluorescent materials, and discloses fluorescent powder as well as a preparation method and application thereof. The chemical formula of the fluorescent powder is Ba < 2.92 > Mg < 0.08 > BP3O12: 12% Eu < 2 + > / Eu < 3 + >. The fluorescent powder not only can be applied to the field of optical temperature measurement, but also can be applied to the field of white light LED illumination. When being applied to optical temperature measurement, the optical temperature sensor has the advantages of quick effect, high resolution, high sensitivity, high temperature resistance, no need of direct contact with an object and the like, and can still ensure high discrimination degree of signals while performing high-sensitivity test. The fluorescent powder can be used as a white light LED device after being mixed with commercial fluorescent powder, white light emitted by the prepared LED device is high in color rendering index and high in luminous efficiency, and the light color does not change along with the change of current and temperature and is stable.

The invention discloses a synthesis method of lead ruthenate powder, which comprises the following steps: S1, weighing ruthenium dioxide powder and lead oxide powder, mixing, and adding a solvent; s2, coarsely and uniformly mixing the mixture of the powder and the solvent, and scattering possible dry powder agglomerates; s3, adding the mixture into grinding equipment for grinding; s4, adding a surfactant into the mixture; s5, carrying out drying treatment on the mixture for 12 to 24 hours at the temperature of 130 to 180 DEG C; s6, putting the dried mixture into a crucible, and calcining at the temperature of 550-800 DEG C for 2-8 hours to form lead ruthenate powder; s7, the lead ruthenate powder is ground; s8, drying the ground lead ruthenate powder at the temperature of 130 to 180 DEG C for 12 to 24 hours; and S9, the dried lead ruthenate powder is packaged. According to the invention, the particle size of the initial powder can be reduced, the synthesis temperature is obviously reduced, the mixing uniformity of the initial powder is greatly improved, and the electrical properties of the resistance paste are finally improved.

The invention discloses an S anion modified ReB2 catalyst, a preparation method and application of the S anion modified ReB2 catalyst in hydrogen production through wide-pH-value electro-catalytic water splitting, and belongs to the technical field of catalyst synthesis and application of electro-catalytic water splitting. According to the molten salt assisted preparation method of the S anion modified ReB2 catalyst, the S anion doped diboride electrocatalyst (S-ReB2) is synthesized in one step under the relatively mild condition, the nano-sheet-shaped morphology is beneficial to exposure of more catalytic active sites, meanwhile, the electronic structure of metal Re in the catalyst is adjusted through doping of S, and the performance of the catalyst is improved. Therefore, the S-ReB2 has excellent catalytic performance on electro-catalytic hydrogen evolution reaction (HER) in electrolytes with different pH values. According to the S anion modified ReB2 catalyst prepared by the invention, the problem that the catalyst is extremely easy to corrode under the strong acid / alkali strong oxidation condition of metal boride is solved, and the energy conversion efficiency of converting electric energy into chemical energy is improved.

The invention belongs to the technical field of electrocatalytic biomass conversion catalysts, and particularly discloses a CuNi catalyst and a preparation method and application thereof.The preparation method comprises the steps that a nickel foil serves as a substrate, and the surface of the nickel foil is pretreated to remove an oxidation film on the surface of the nickel foil; the pretreated nickel foil serves as a working electrode, Ag / AgCl serves as a reference electrode, a 2 * 1 cm platinum sheet serves as a counter electrode, deposition electrolyte is added, stirring is continuously conducted at the rotating speed of 600 rmp, deposition is conducted through CV circulation under the voltage of + 0.5 V to-2 Vvs Ag / AgCl, and the coulombic amount of deposition is 5-20 C; and washing the obtained precipitate with water and ethanol respectively, and then drying in a vacuum drying oven at 60-70 DEG C for 7 minutes to obtain the CuNi bimetallic catalyst. When the CuNi catalyst prepared by the method is used for synthesizing 2, 5-dimethylolfuran through electro-catalysis and hydrogenation of 5-hydroxymethylfurfural, HMF is successfully converted in a mild and clean mode, and the method has the advantages of being low in cost, high in yield, very high in practicability and very good in industrialization prospect.

The invention belongs to the technical field of energy storage materials, relates to a lithium ion battery electrode material, and discloses a titanium niobate material rich in stacking fault defects and a preparation method and application thereof. The crystal structure of the titanium niobate material at least comprises a fault defect, the fault defect is that an atomic layer is inserted into the normal sequence of the crystal of the titanium niobate, the stacking sequence of the atomic layer is different from that of the other atomic layers, and two reverse-sequence stacking layers appear at the position. The precursor subjected to heat treatment is subjected to quenching treatment, the fault defect structure is introduced, the electron energy band structure of the TNO crystal is changed through introduction of the fault defect structure, the forbidden band width of quenched TNO is shortened, the electronic conductivity of the material is improved, impedance is reduced, and the electrochemical performance of the material is improved. Meanwhile, the Li < + > diffusion rate is increased, the ionic conductivity is improved, and the electrochemical performance is improved.

The application relates to high-sphericity nano tetragonal barium titanate for MLCCs and a preparation method thereof. The technical scheme is as follows: a titanium source, a dissolving agent and potassium perchlorate are mixed to obtain mixed material A; the mixed material A is heated twice under air condition, is preserved, is naturally cooled to obtain a reaction product; the reaction product is washed with distilled water I, is separated, is dried to obtain titanium dioxide powder; the titanium dioxide powder and barium oxide are mixed to obtain mixed material B; the mixed material B, ethylene glycol, pure water and an anionic surfactant are mixed to obtain a mixed solution; the mixed solution is moved to a polytetrafluoroethylene reaction kettle, is placed in a microwave heating furnace, is heated, is preserved, is naturally cooled and is filtered; the filtered product is washed with distilled water II, is separated, is dried to obtain high-sphericity nano tetragonal barium titanate for MLCCs. The product prepared by the application has high purity, high sphericity, small particle size, good dispersity and high tetragonality.

The application discloses a high-entropy rare earth silicate ceramic powder and a preparation method and application thereof. The preparation method of the high-entropy rare earth silicate ceramic powder comprises the following steps: 1) mixing rare earth oxide powder, SiO2 powder, LiCl and KCl and grinding to obtain a mixed powder; and 2) calcining the mixed powder under the condition that the temperature is 700 DEG C to 900 DEG C, and then performing water washing and drying to obtain the high-entropy rare earth silicate ceramic powder. The high-entropy rare earth silicate ceramic powder has the excellent characteristics of high purity, small particle size, uniform element distribution and large component space, and the preparation method has the advantages of short preparation period, low synthesis temperature, small energy consumption and high efficiency, is suitable for being used on a hot end part of an aerospace engine and has a very wide application prospect.

The application discloses a kind of super narrow band purple light fluorescent powder, its chemical general formula is A2M (PO3) 4:zEu 2+ Wherein, A is one or more of Na, K, M is one or more of Ca, Sr, Ba;Super narrow band refers to the half-height width of fluorescent powder emission spectrum is less than 25nm.The application also discloses the preparation method of the super narrow band purple light fluorescent powder, including the following steps: raw material ball milling, slow pre-calcination, multi-section heat preservation and finally increase to 200~350 DEG C, cooling grinding;Finally, under reducing atmosphere, 550~700 DEG C is synthesized, after cooling grinding.The application further discloses the application of the super narrow band purple light fluorescent powder in display device and temperature sensing.The fluorescent powder obtained in the application is super narrow band purple light emission under near ultraviolet light excitation, high color purity, high luminous efficiency, good chemical stability;The production process of fluorescent powder is simple, synthesis temperature is low, green and environmental protection.

The present application discloses a method for preparing boron nitride nanotubes and boron nitride nanotubes, the preparation method comprising weighing raw materials into a reactor, the raw materials comprising carbonate, magnesium oxide and a boron precursor; heating the reactor to a reaction temperature under an inert atmosphere to generate a precursor, the reaction temperature being 850 to 1200°C; placing the reactor under an ammonia atmosphere, maintaining the reaction temperature, and continuously reacting to generate boron nitride nanotubes; cooling the reactor to room temperature under an inert atmosphere to obtain boron nitride nanotubes. The preparation method of the present application can grow boron nitride nanotubes at a relatively low temperature of 850°C, and a large amount of high-quality boron nitride nanotubes can be obtained at 950°C, effectively reducing the synthesis temperature of boron nitride nanotubes, reducing the preparation cost of boron nitride nanotubes, and contributing to the wide application and industrial production of boron nitride nanotubes.

The invention provides beta-MnOOH, the beta-MnOOH is a three-dimensional net-shaped spherical or sphere-like secondary particle formed by winding a ribbon-shaped primary particle, and the secondary particle is loose and porous; the beta-MnOOH has a specific surface area of 50 m2 / g or more. The beta-MnOOH is high in specific surface area and high in activity, and is an excellent manganese oxide precursor and catalyst. The invention also provides a preparation method of the beta-MnOOH, the beta-MnOOH is synthesized through a one-step liquid phase precipitation method, the synthesis efficiency is high, the synthesis temperature is low, the oxidation degree of manganese is controllable through process control, and the beta-MnOOH with stable valence state and excellent morphology is obtained. The preparation method is relatively high in process stability, simple in process, simple in equipment requirement, free of a complexing agent, relatively low in cost, capable of realizing large-scale production and easy to realize industrialization.

The invention provides a method for preparing a Schottky-type photocatalyst, which relates to the technical field of photocatalysis, and comprises the following steps: S1: acidifying, stripping and reorganizing layered KTiNbO5 in sequence to obtain H+-recombined HTiNbO5 nanosheets (HTiNbO5-Ns); S2: washing and drying the H+-recombined HTiNbO5 nanosheets (HTiNbO5-Ns); the invention uses KTiNbO5 as a raw material and undergoes three processes of acidification, stripping and reorganization to obtain H+-recombined HTiNbO5 nanosheets (HTiNbO5-Ns). + ‑Recombinant HTiNbO5 nanosheets (HTiNbO5‑Ns) have a larger surface area and porous structure. Ti3C2MXene is obtained by completely etching the Al layer in Ti3AlC2. A nanosheet Schottky heterojunction is constructed by combining it with a few-layer HTiNbO5 nanosheets using a simple hydrothermal method. The raw materials for the preparation are common and easily available, the process flow is simple, and the operation is convenient.

The invention is applicable to the technical field of boron phosphide polycrystalline synthesis, and provides a method for synthesizing a boron phosphide polycrystalline block by using an amorphous boron source and a phosphorus source through a one-step method, which comprises the following steps: fully ball-milling and mixing amorphous boron powder and amorphous phosphorus powder; pressing the raw materials into a cylinder; the cylinder is placed in a high-pressure assembly, then the high-pressure assembly is placed in a cavity of a cubic press, and heating is conducted for 60 min under the conditions that the pressure ranges from 2 GPa to 5 GPa and the temperature ranges from 950 DEG C to 1350 DEG C. The invention also provides a boron phosphide polycrystalline block and an application of the boron phosphide polycrystalline block in preparation of a high-heat-dissipation device. The boron phosphide polycrystalline ceramic sintered body is synthesized at high temperature and high pressure through a one-step method by adopting a domestic cubic press, the cost is low, the time is short, the process is simple, the pressure is relatively low, and the yield is high; the synthesized sample has the characteristics of simple process, high hardness, high heat conductivity and the like, has very wide application potential, can be used for superhard inorganic compounds, refractory materials, high heat dissipation devices or ships and the like, and can prevent ship bodies and parts from being corroded by seawater and the like.