252 results about "Tungstate" patented technology

The invention provides application of a silver-bismuth tungstate catalyst in preparation of methanol from light-driven CO2, and belongs to the technical field of CO2 conversion and reduction. Bismuth tungstate nanosheets, silver salt and water are mixed, the size of silver particles is controlled by adjusting the pH value, the silver-bismuth tungstate catalyst is obtained, and the size of the silver particles is 20-50 nm; silver is evenly distributed on the surface of bismuth tungstate, the obtained silver-bismuth tungstate catalyst is large in specific surface area and high in light response capacity, the silver-bismuth tungstate catalyst can generate a large number of high-energy hot electrons during illumination, in-situ photo-thermal conversion is achieved, no external heat source is needed for heat supply, the photo-thermal effect is enhanced, CO2 conversion is promoted, and the methanol yield is increased.

The invention provides a rapid preparation method of tungsten trioxide, which specifically comprises the following steps: step 1, weighing crude tungstic acid, dissolving in ammonia water, heating and stirring to obtain an ammonium tungstate solution; step 2, slowly dropwise adding the ammonium tungstate solution in the step 1 into a poor solvent to obtain an ammonium paratungstate suspension, and step 3, filtering the ammonium paratungstate suspension in the step 2 to obtain an ammonium paratungstate filter cake, and leaching the ammonium paratungstate filter cake with the poor solvent; 4, the ammonium paratungstate filter cake in the step 3 is placed in a drying oven to be dried; and (5) roasting the ammonium paratungstate filter cake in the step (4) at high temperature to obtain a faint yellow irregular flaky tungsten trioxide product. According to the preparation method, a mixed solvent crystallization and high-temperature roasting two-step process is adopted, the solubility of ammonium tungstate in water is reduced by adding a poor solvent, so that an ammonium tungstate solution rapidly reaches a saturated state and is separated out, the crystallization process of ammonium paratungstate is accelerated, and the preparation speed and the crystallization rate of a tungsten trioxide product are high.

The application relates to a preparation method and application of a ball milling-calcination process-prepared cesium vanadium tungstate mixed heat insulation coating, and belongs to the technical field of heat insulation coatings. The application aims to solve the problems of high preparation cost, strict requirement on equipment, long preparation time and difficult morphology control of vanadium dioxide and cesium tungsten bronze used in the existing cooling coating. The prepared cesium vanadium tungstate mixed heat insulation coating is coated on the surface of glass, mainly aiming at blocking the infrared light thermal radiation in sunlight, the new type of high-efficiency heat insulation film utilizes the light absorption and phase change reflection characteristics of nanometer cesium tungsten bronze and vanadium dioxide to realize heat insulation. The application adjusts the proportion of cesium, vanadium and tungstate to adjust the heat insulation performance, the heat insulation coating is prepared through different proportions of acrylic resin / organic silicon resin, solvent, cesium vanadium tungstate mixed heat insulation coating and the like, and the heat insulation film with excellent infrared blocking property, good stability and excellent light transmittance is obtained.

The invention discloses a high-voltage lithium nickel manganese oxide positive electrode material and a preparation method thereof, a battery positive electrode and a battery, and belongs to the technical field of lithium ion battery materials. Comprising an inner core composed of a lithium-containing compound, the inner core is coated with a shell composed of tungstate, and a transition layer is arranged between the inner core and the shell. The tungstate has good chemical and thermodynamic stability, can prevent erosion of HF in the electrolyte, inhibit dissolution of transition metal, reduce the shuttle effect, and can greatly improve the capacity retention rate of the battery. The preparation method is simple in process steps and convenient for large-scale preparation. Meanwhile, the cathode material coated with magnesium tungstate, calcium tungstate or bismuth tungstate has good dynamic performance, the capacity and the rate capability are remarkably improved, meanwhile, the stability of the material is also remarkably improved, and a good application way is provided for application of the high-voltage type lithium nickel manganese oxide cathode.

The invention relates to a WO-NiSe CeO2 self-supporting heterostructure catalyst and a preparation method thereof. The preparation method comprises the following steps: preparing Ni LDH at CeO2 on foamed nickel through a hydrothermal method, then realizing high-valence tungstate radical doping through impregnation exchange, and finally carrying out secondary hydrothermal selenylation to obtain a porous nanosheet heterojunction material with CeO2 nanoparticles attached to the surface, namely WO-NiSe at CeO2. The introduction of high-valence tungstate radicals and the coupling of CeO2 form a strong electron coupling interface on the surface of NiSe, and HER / OER charge transfer is accelerated. And according to a hard-soft acid-base (HSAB) theory, the high-valence metal serving as a relatively hard Lewis acid shows higher selectivity on OH <-> than Cl <->, so that accumulation of Cl <-> on the surface of the catalyst can be inhibited, the catalytic activity is remarkably improved, and the corrosion-resistant life is remarkably prolonged. According to the strategy, a new'activity-stability-cost 'ternary equilibrium normal form with the advantages of low overpotential, long-period stability and salt corrosion resistance is provided for seawater electrolytic hydrogen production, and the theoretical value and the industrialization potential are both achieved.

The invention belongs to the technical field of functional materials, and particularly relates to ultra-thick tabular tungsten oxide and a preparation method thereof.The preparation method of the ultra-thick tabular tungsten oxide comprises the following steps that S1, ammonium tungstate is added into deionized water and stirred to be dissolved at the temperature of 70-90 DEG C, and a clarified ammonium tungstate solution is obtained; s2, cooling the clarified ammonium tungstate solution to normal temperature at a cooling rate of 0.5-2 DEG C / h, and then carrying out suction filtration to obtain plate-shaped ammonium tungstate crystals; s3, calcining the tabular ammonium tungstate crystal to obtain ultra-thick tabular tungsten oxide; ammonium tungstate is adopted as a raw material, controllability is high, tungsten oxide which is uniform in particle size and complete in plate shape is obtained through optimized crystallization and calcination, the purity is larger than or equal to 99%, the problems that traditional tungsten oxide is agglomerated and disordered in shape are solved, functional adaptability is high, the plate-shaped structure can be directionally oriented, the dielectric performance, the breakdown performance and other performance are improved, and the method is suitable for multiple high-end scenes; parameters are easy to control, and operation is simple, green and safe.

The invention belongs to the technical field of electro-catalysis water decomposition, and relates to a self-supporting W-NiCoP / NF composite material and a preparation method and application thereof. Cobalt salt, terephthalic acid, acetic acid and foamed nickel are subjected to a first solvothermal reaction, and defect type Co-MOF / NF is obtained; immersing the defect type Co-MOF / NF into a tungstate solution, and then carrying out a second solvothermal reaction to obtain a defect type W-Co-MOF / NF precursor; and carrying out phosphating heat treatment on the defect type W-Co-MOF / NF precursor and a phosphorus source in an inert atmosphere to obtain the W-Co-MOF / NF composite material. According to the preparation method disclosed by the invention, the tungsten-doped nickel-cobalt bimetallic phosphide with rich defect structures is successfully constructed on the foamed nickel substrate through a step-by-step solvothermal and gas-phase phosphating strategy, so that organic combination of a bimetallic synergistic effect and defect engineering is realized; the prepared self-supporting composite material has more active sites, a better electronic structure regulation effect and better stability.

The invention provides a cobalt tungstate and bismuth vanadate photocatalytic material as well as a preparation method and application thereof, and belongs to the technical field of material synthesis and photocatalytic application. In the presence of monoclinic-phase decahedron BiVO4, CoWO4 nanoparticles grow in situ on an electron-rich (010) crystal face of the CoWO4 nanoparticles through a hydrothermal reaction, and the cobalt tungstate and bismuth vanadate photocatalytic material is obtained. According to the cobalt tungstate and bismuth vanadate photocatalytic material, a simple hydrothermal method is adopted, in the synthesis process, a CoWO4 precursor is guided by electrostatic interaction, preferentially adsorbed and subjected to nucleation growth on the (010) crystal face of BiVO4, a compact chemical bonding interface is constructed through selective growth, the charge migration distance is effectively shortened, and the photocatalytic performance of the material is improved. The interface charge transfer resistance is reduced to the greatest extent, and the formed binary photocatalyst has excellent effects on photocatalytic hydrogen evolution and tetracycline degradation.

The invention belongs to the technical field of tungsten hydrometallurgy, and particularly relates to a method for improving the crystallization rate of ammonium paratungstate, which comprises the following steps: S1, obtaining an ammonium tungstate solution which comprises metatungstate ions; s2, adding a supersaturation degree regulator into the ammonium tungstate solution, wherein the supersaturation degree regulator comprises hydrogen peroxide and ammonia water; s3, heating the ammonium tungstate solution to a first temperature, and then adding superfine ammonium paratungstate; s4, the ammonium tungstate solution is heated to a second temperature, heat preservation and continuous stirring are conducted, and ammonium paratungstate crystals are obtained; by adjusting parameters such as temperature, pH value, solvent type and concentration, optimizing crystallization conditions with metatungstate ions and ammonium paratungstate at the same time, improving the crystallization rate, and by controlling the degree of supersaturation of the solution, the situation that the crystallization rate is affected due to non-uniform crystal growth caused by too high crystallization rate is avoided, and the quality of the product is improved. The supersaturation degree can be controlled by adjusting parameters such as solution concentration and temperature.

The invention discloses a post-treatment liquid and application thereof in an anode foil formation post-treatment process, and the post-treatment liquid comprises the following components in percentage by mass: 0.1-5% of a main film-forming agent, 0.05-3% of a synergistic stabilizer and the balance of a solvent, the main film-forming agent is selected from at least one of a waterborne polyurethane emulsion and a silane coupling agent; the synergistic stabilizer is selected from at least one of organophosphate, molybdate and tungstate. The main film-forming agent and the synergistic stabilizer are compounded to obtain the post-treatment liquid, on one hand, the synergistic stabilizer is firmly combined with an aluminum oxide substrate to carry out deep passivation treatment on an oxidation film on the surface of the anode foil, and on the other hand, the synergistic stabilizer is subjected to network crosslinking with a hydrophobic protection layer formed by the main film-forming agent; the three-dimensional composite protective film can effectively isolate water molecules, repair microdefects on the surface of an oxidation film, prevent the phenomena of specific volume attenuation, leakage current increase and the like of the anode foil, and improve the long-term working reliability of the capacitor.

The invention relates to the technical field of catalysts, and particularly discloses a composite catalyst for preparing acrolein through catalytic oxidation of propylene and a preparation method of the composite catalyst, the composite catalyst comprises an active component I and an active component II, and the use mass ratio of the active component I to the active component II is 1: (1-19); the active component I is bismuth tungstate microspheres obtained by a hydrothermal synthesis method, and the general formula of the active component I is BiaW1Ox; the active component II is a multi-metal oxide obtained by a coprecipitation method, and the general formula of the active component II is Mo < 12 > Bi Co < c > Ni < d > Fe < e > A < f > B < g > O < y >; the bismuth tungstate microspheres obtained by a hydrothermal synthesis method and the multi-metal oxide obtained by a coprecipitation method are mixed to obtain the composite catalyst, so that the bismuth tungstate microspheres with microsphere structures can be used as active phases of reaction, and the specific surface area and the pore volume of the composite catalyst can be increased; the catalyst is suitable for a reaction for preparing acrolein through propylene catalytic oxidation under high load.

The invention discloses a method for recycling process water in an APT (ammonium paratungstate) production process, and relates to the field of water recovery in an APT production process, and the method comprises the following steps: S1, recycling wastewater of an alkali extraction system; s2, evaporating strip liquor and recovering ammonia water; s3, chemical treatment of pure ammonium tungstate evaporation ammonia water; s4, ammonium molybdate evaporation ammonia water closed-loop utilization; and S5, recycling ammonia gas in a crystallization section. According to the method, the recovery rate of tungsten and molybdenum in the tail liquid is remarkably increased by optimizing the processes of wastewater reuse of the alkali extraction system, strip liquor evaporation, ammonia water recovery and the like; one part of the tail liquid is recycled in the pulping process, the other part of the tail liquid is subjected to evaporation treatment, zero emission of wastewater is achieved, evaporated condensate water can be recycled to be used for preparing a stripping agent, the utilization rate of water resources is further increased, the production cost is reduced, and meanwhile the environment-friendly requirement is met.

Provided in the present invention is a preparation method for a metal oxide / ruthenium-tungsten composite catalyst and the use of the metal oxide / ruthenium-tungsten composite catalyst in the catalysis of the cleavage of a C-O bond in lignin. The preparation method comprises: weighing a tungstate, dissolving same in deionized water, and stirring the resulting solution until uniform, so as to obtain a solution a; weighing ruthenium chloride, dissolving same in deionized water, and stirring the resulting solution until uniform, so as to obtain a solution b; mixing the solution a with the solution b, so as to obtain a solution c; dissolving a nanometer metal oxide in deionized water, and stirring same, so as to obtain a solution d; S4, adding, in a dropwise manner, the solution c to the solution d, so as to obtain a solution e, and subjecting the solution e to rotary evaporation and a vacuum drying treatment, so as to obtain a catalyst precursor; and S5, placing the catalyst precursor into a tubular furnace, and reducing same in a H2 / Ar atmosphere, so as to obtain a metal oxide / ruthenium-tungsten composite catalyst. In the present invention, a metal oxide carrier is loaded with ruthenium and tungsten by means of an impregnation method, the preparation process is simple, and environmental pollution and energy consumption are low; and a lignin model compound is efficiently catalytically cracked into an aromatic compound under mild conditions, and few by-products are produced.

The invention belongs to the technical field of high-activity tungsten powder preparation, and particularly relates to high-specific-surface-area high-activity tungsten powder and a preparation method thereof.The preparation method comprises the steps that diluted hydrochloric acid is added into an ammonium tungstate solution to adjust the pH to be acidic, then hydrogen peroxide is added, and a mixed solution is obtained; carrying out vacuum drying on the mixed solution at the temperature of less than or equal to 80 DEG C to obtain a solid substance; and in the hydrogen atmosphere, the solid matter is reduced, the tungsten powder with the high specific surface area and the high activity is obtained, and the specific surface area is larger than or equal to 10 m < 2 > / g. According to the technical scheme, ammonium chloride and peroxotungstic acid are creatively applied to be subjected to low-temperature heating decomposition to generate a large amount of gas to form a porous framework, and therefore the nano tungsten powder controllable in granularity, good in dispersity, high in specific surface area and high in activity is prepared; the performance of the high-specific-surface-area and high-activity nano tungsten powder can be controlled by simply controlling process conditions; and the application potential of the nano tungsten powder as a novel high-performance tungsten material is increased.

The invention relates to the technical field of photocatalytic materials, in particular to a multi-ion doped TiO2 nanosheet material suitable for degradation of dyes in water and a preparation method of the multi-ion doped TiO2 nanosheet material. The preparation method comprises the following steps: pre-embedding a self-sacrifice template in a germanium-tungsten composite doping solution, carrying out hydrothermal conversion to construct a Ge-W synergetic optimized regular TiO2 substrate, carrying out atomic layer deposition to realize nitrogen / silver uniform doping, and carrying out synergetic surface modification on silver nitrate-ethanolamine and perfluorosilane to prepare the TiO2 nanosheet material. Germanate serves as lattice strain guidance to guide TiO2 lattice growth to form a low-defect matrix, tungstate is cooperatively doped in the matrix to construct a strong built-in electric field to improve the charge separation efficiency, Ge-W elements cooperate to stabilize a bulk phase and a grain boundary, and a gradient protection barrier is constructed with selective shielding of a fluorosilane layer. The TiO2 catalyst is synergistically improved in the aspects of high catalytic activity and long-acting environmental stability, and is suitable for efficient pollutant purification in a complex water quality environment.

The invention discloses a preparation method and application of a heterojunction catalyst based on a two-dimensional zinc porphyrin metal organic framework, and belongs to the field of photochemical energy conversion and photocatalytic degradation. The invention aims to solve the technical problems of high-quality preparation of the artificial photosynthetic photocatalytic composite material and how to effectively improve the photochemical energy conversion efficiency. The method comprises the following steps: 1, dissolving bismuth nitrate pentahydrate, sodium tungstate dihydrate and sodium dodecyl dimethyl benzene sulfonate in deionized water, fully stirring, and transferring the solution to a reaction kettle for hydrothermal reaction; cooling to room temperature, washing and drying to obtain bismuth tungstate solid powder; 2, adding bismuth tungstate and meso-tetra (4-carboxyl phenyl) porphin into a mixed solution of N, N-dimethylformamide and ethanol, carrying out ultrasonic treatment, and fully stirring to obtain a solution A; dissolving zinc nitrate hexahydrate, pyrazine and polyvinylpyrrolidone in a mixed solution of N, N-dimethylformamide and ethanol, and fully stirring to obtain a solution B; after the solution is fully dissolved, dropwise adding the solution B into the solution A under ultrasonic and stirring conditions, and then putting the beaker into an oil bath pan for heating; and cooling to room temperature, washing, and storing in an ethanol solution to obtain the Zn-MOF / Bi2WO6 heterojunction composite material.

The invention discloses a phosphorus-modified cobalt tungstate difunctional electrode material, a preparation method thereof and application of the phosphorus-modified cobalt tungstate difunctional electrode material in water electrolysis hydrogen production, and the electrode material is obtained by taking foamed nickel as a substrate material and synthesizing phosphorus-modified cobalt tungstate nanoparticles on the substrate material; the preparation method comprises the following steps: firstly, pretreating a substrate material, then carrying out hydrothermal reaction on the pretreated substrate material, cobalt salt and a tungstate solution, then carrying out phosphorus modification, and finally obtaining the phosphorus-modified cobalt tungstate difunctional electrode material. The bifunctional electrode material disclosed by the invention not only has excellent water electrolysis hydrogen production performance, but also has good oxygen evolution performance; the preparation method is simple, only simple hydrothermal reaction and calcination are needed, and the preparation raw materials are low in cost and easy to obtain, so that the bifunctional electrode material can be produced on a large scale at low cost, and large-scale application of hydrogen production by water electrolysis is facilitated.

The application belongs to the technical field of metallurgy, and particularly relates to a preparation method of high-purity ammonium tungstate solution. The application provides a preparation method of high-purity ammonium tungstate solution, which comprises the following steps: performing first adsorption on a crude ammonium tungstate solution to obtain saturated adsorption resin; sequentially performing elution and desorption on the saturated adsorption resin to obtain tungsten-containing desorption solution; performing purification on the tungsten-containing desorption solution to obtain tungsten-containing purified solution; and performing second adsorption on the tungsten-containing purified solution to obtain the high-purity ammonium tungstate solution. Compared with the existing solvent extraction, the application adopts the chromatography column method to separate and purify tungsten, and the tungsten can be obtained through adsorption, elution, desorption, purification and secondary adsorption, so that the process flow is simple, and the reagent consumption is small. The experimental results show that the purity of the ammonium tungstate solution obtained by the application can reach more than 99.9995%.

The invention relates to a rare earth metal tungstate nanosheet material as well as a preparation method and application thereof. The rare earth metal tungstate nanosheet material comprises a PO4 < 3->-LnWO4 nanosheet, and Ln is at least one of lanthanide series rare earth metals. The preparation method comprises the following steps: dissolving phosphotungstic acid and a precursor in a solvent, and stirring to form a solution; adding an organic amine ligand, and stirring to form a transparent solution; performing solvothermal reaction on the solution; and centrifuging, washing with ethanol and drying to obtain the rare earth metal tungstate nanosheet material. A solvothermal reaction method is adopted to successfully construct a two-dimensional sheet structure material formed by interweaving nanowires, the material has high specific surface area, abundant pores and excellent structural stability, and the problems that a traditional photocatalytic material is single in structure and insufficient in active site are effectively solved. The photocatalyst shows excellent degradation capability on various typical antibiotic pollutants, breaks through the limitation that most photocatalytic materials are only effective on single pollutants, and realizes relatively high pollutant degradation universality.

The present application relates to a kind of preparation methods of sulfur vanadium co-doped bismuth tungstate visible light catalyst, the catalyst is assisted by urea hydrothermal method, with sodium tungstate, bismuth nitrate, thiourea, citric acid, ammonium metavanadate, urea as raw material, configuration certain concentration of thiourea and citric acid aqueous solution as sulfur source;Configuration certain concentration of ammonium metavanadate aqueous solution as vanadium source.Sulfur source and vanadium source are mixed after drop by drop to be added to bismuth nitrate solution, after stirring, transfer to hydrothermal kettle, the hydrothermal kettle is placed in blast oven and hydrothermal treatment cooling, centrifugal separation product, washing and drying obtain sulfur vanadium co-doped BWO visible light catalyst.The method is obtained by one-step hydrothermal treatment flower cluster of bismuth tungstate nanosheet composition, simple process, low equipment requirement, the composite photocatalyst prepared has stronger response under visible light condition, has higher application value in pollution control, environmental protection, new energy preparation and other fields.

The present application relates to the technical field of ore-dressing wastewater treatment, and particularly relates to a magnetized photocatalyst through magnetic separation concentrate, and a preparation method and application thereof. The present application disperses the magnetic separation concentrate after ball milling into a mixed solution of anhydrous ethanol, water and ammonia water to obtain a suspension 1; a mixed solution of tetraethyl orthosilicate and anhydrous ethanol is added into the suspension 1 to perform coating to obtain gamma-Fe2O3@SiO2; the photocatalyst, a solvent and gamma-Fe2O3@SiO2 are mixed to obtain the magnetized photocatalyst; the photocatalyst is bismuth tungstate or bismuth oxyiodide. Under the optimal conditions, the degradation efficiency of the photocatalyst on xanthate can reach 100%, and the photocatalyst can be recycled through magnetism, so that the operation cost is greatly reduced, and the photocatalyst has a good application prospect. The present application utilizes the natural magnetic hematite gamma-Fe2O3, avoids the problems of numerous artificial synthesis steps and high cost, and has a wide application prospect in the field of magnetic photocatalysts.

The invention belongs to the technical field of photothermal conversion materials, and discloses a preparation method and application of an inorganic-organic hybrid polyoxotungstate photothermal material with wide spectrum absorption. The structural formula of the photo-thermal material is Per4W10O32, the crystal structure belongs to a triclinic system, the space group is P-1, and the photo-thermal material has specific unit cell parameters. The preparation method comprises the following steps: oxidizing perylene molecules through constant current electrolysis in a mixed solvent system containing perylene molecules and a decatungstate precursor in an electrochemical oxidation manner, and assembling the oxidized perylene molecules with decatungstate anions to form bulk crystals; the photo-thermal material has continuous strong absorption in a region from ultraviolet light to short wave infrared, the photo-thermal conversion efficiency is as high as 98.24%, when the photo-thermal material is applied to the fields of solar driven interface photo-thermal evaporation and water treatment, the evaporation rate of a two-dimensional system is 1.89 kg.m <-2 >. H <-1 >, the evaporation rate of a three-dimensional hydrogel system is increased to 3.02 kg.m <-2 >. H <-1 >, salt deposition can be inhibited in long-term seawater desalination operation, and the photo-thermal material has a good application prospect. Fresh water quality meets drinking water standards.

The application belongs to the field of antibacterial two-dimensional nanomaterial Mxene catalysts, and particularly relates to a monolayer W@MoS2 nanosheet as well as a preparation method and application thereof. The method comprises the following steps: 1) dissolving water-soluble molybdate and water-soluble tungstate in water to obtain a mixed solution; 2) adding a sulfur source and an organic solvent to the mixed solution, and then performing reaction after mixing, and drying to obtain a powder. The monolayer W@MoS2 nanosheet has a unique two-dimensional planar structure, a large specific surface area, and good optical and electronic properties, and has high light-heat absorption in the near-infrared two region, i.e., the light-heat conversion efficiency is improved. Meanwhile, the peroxidase-like activity of the monolayer W@MoS2 nanosheet material realizes efficient light-heat amplification, can treat methicillin-resistant Staphylococcus aureus infection, and avoids heat therapy damage to normal tissues.

This invention discloses a high-temperature conductive graphene solution and its preparation method, comprising the following components by weight: 1800-2000 parts of a dispersion containing 3-5 nm graphene quantum dots, wherein the quantum dot content is 5-10 wt%; 450-510 parts of tin dioxide with a particle size ≤0.2 μm; 15-20 parts of ammonium tungstate and 15-20 parts of lanthanum oxide; 30-40 parts of manganese chloride tetrahydrate, 20-30 parts of nickel chloride, and 20-30 parts of copper chloride; 8000-10000 parts of a solvent system, wherein deionized water ≤4000 parts, anhydrous ethanol ≤5000 parts, isopropanol ≤100 parts, and n-butanol ≤50 parts; 800-1000 parts of tri-n-butyltin hydride and 100-300 parts of citric acid. Due to the adoption of the above technical solutions, this application has achieved breakthroughs in the stability of conductive networks through quantum dot bridging mechanisms; the standard deviation of electron migration path length has been reduced from 1.2 μm to 0.08 μm; the heterojunction interface has been optimized and a Type-II band structure has been formed, resulting in an 82% reduction in contact resistance.

This invention relates to the field of metal protection and lubrication materials, and discloses a silent, vibration-damping, film-forming, long-lasting rust-preventive oil for bearings and its preparation method. The rust-preventive oil comprises a base oil, a dynamic borate ester-organosilicon-tungsten bridging synergistic modifier, itaconic acid hydrazine, a dimer ester, calcium petroleum sulfonate, polyisobutylene, a phosphate extreme pressure agent, and an antioxidant. The dynamic borate ester-organosilicon-tungsten bridging synergistic modifier forms a reversible dynamic covalent network of borate esters with phenylboronic acid through a diol-based compound, and then undergoes a confined sol-gel polymerization reaction with vinyltriethoxysilane to form silicon-oxygen segments. These segments are then coordinated and bridged by tungstate and diol groups to construct a three-dimensional coupled structure. The rust-preventive oil of this invention has advantages such as high film density, strong adhesion, good vibration damping and noise reduction effect, and strong rust prevention durability, making it suitable for the storage and operational protection of high-end bearings.

The application discloses a method for homogenizing a chemical synthetic multi-component alloy, and the method comprises the following steps: dissolving ammonium molybdate and ammonium tungstate in deionized water to obtain a mixed solution of ammonium molybdate and ammonium tungstate; dissolving polyethyleneimine in deionized water to obtain a polyethyleneimine solution; adding the polyethyleneimine solution into the mixed solution of ammonium molybdate and ammonium tungstate to uniformly disperse the precipitate; completely evaporating the solvent by using a rotary evaporation method to obtain a powder; performing secondary reduction on the powder to obtain a reduced powder; sintering the reduced powder in a graphite mold; heating the sintered product to 1500-1600 DEG C by using a medium-frequency induction furnace, extruding the sintered product on a horizontal extruder, naturally cooling the sintered product, and then annealing the sintered product at 1300-1400 DEG C. Compared with solid-state mixing, the method can save a mechanical alloying process and reduce sintering forming power in solidification forming; compared with liquid-phase mixing, the method can improve the uniformity of element mixing; compared with gas-phase mixing, the method can improve material utilization, reduce preparation cost and homogenization difficulty, and has no environmental pollution.

This invention belongs to the field of metal powder preparation technology, specifically relating to a uniform ultrafine tungsten powder and its preparation method. The preparation method includes the following steps: S1, obtaining an ammonium tungstate solution and a first solvent; the first solvent is obtained by mixing water and ethanol; S2, adding the ammonium tungstate solution and hydrazine hydrate solution dropwise into the first solvent to obtain a first system; the molar ratio of hydrazine hydrate to WO3 in the ammonium tungstate solution is (4-9):1; S3, continuously stirring the first system to allow it to crystallize, then filtering and drying to obtain a precursor powder; S4, heating the precursor powder under a protective gas atmosphere to cause the precursor powder to self-reduction to obtain uniform ultrafine tungsten powder. The prepared uniform ultrafine tungsten powder has a uniform particle size, with an average particle size of 100-400 nm. This invention allows for controllable dosage of the reducing agent, thorough reduction, and uniform tungsten powder particle size; it can obtain high-purity tungsten powder and avoids the introduction of impurities; it has advantages such as simple operation, high reproducibility, short process, simple equipment, easy industrialization, and cost savings.

Provided is a method for preparing a diol. In the method, a saccharide and hydrogen as raw materials are contacted with a catalyst in water to prepare the diol. The employed catalyst is a composite catalyst comprised of a main catalyst and a cocatalyst, wherein the main catalyst is a water-insoluble acid-resistant alloy; and the cocatalyst is a soluble tungstate and / or soluble tungsten compound. The method uses an acid-resistant, inexpensive and stable alloy needless of a support as a main catalyst, and can guarantee a high yield of the diol in the case where the production cost is relatively low.

The invention belongs to the technical field of recycling of rare and noble metal secondary resources, and discloses a method for preparing a tungsten compound and chloroplatinate from a waste catalyst and application of the method. The method comprises the following steps: (1) firing and crushing the waste catalyst, (2) reacting the waste catalyst with acid, (3) filtering and discarding filtrate, (4) reacting the precipitate with ammonia water, filtering to obtain an ammonium tungstate solution, and retaining filter residues; (5) concentrating the ammonium tungstate solution, crystallizing, separating and drying to obtain an ammonium paratungstate finished product; and (6) reacting the filter residues retained in the step (4) with aqua regia to prepare chloroplatinate. And (7) firing the ammonium paratungstate at a high temperature to obtain tungsten trioxide. According to the method, tungsten and platinum can be effectively separated from the carrier, and the recovery rate of rare and precious metals is increased.

The application discloses preparation and application of a kind of antimony tungstate material with catalytic Fenton reaction activity, the molecular formula of the antimony tungstate material is H 11 [Ln2Sb2W7O 23 (OH)(DMF)2(SbW9O 33 )2]·xH2O, abbreviated as 1-Ln, wherein Ln=Dy, Ho, Er, Tm, Y, Yb or Lu;DMF=N or N-dimethylformamide;The crystal structure of the antimony tungstate material is that two three-defect {B-alpha-SbW9O 33} units sandwich one four-core heterometallic cluster {Sb2Ln2O 10 (DMF)2} and one {W7O 29 (OH)} cluster unit to form a high 1.9nm capsule-like isolated cluster structure, which has good water solubility and stability under physiological conditions.The antimony tungstate material with catalytic Fenton reaction activity can generate a large number of ·OH to kill cancer cells by catalyzing H2O2 decomposition and consuming glutathione through Fenton-like reaction, has high cytotoxicity and selectivity to various cancer cells, can significantly inhibit the growth of tumor in vivo, has small toxic and side effects to normal cells and organs, and can be used as an antitumor drug, applied to the field of biological medicine.