321 results about "Ammonium fluoride" patented technology

The invention discloses a plant-based deodorant and a preparation method thereof, and relates to the technical field of high polymer materials. When the plant-based deodorant is prepared, beta-cyclodextrin reacts with paratoluensulfonyl chloride and then reacts with ethylenediamine, and amino modified cyclodextrin is prepared; the plant-based extract is subjected to inclusion with amino modified cyclodextrin, and a cyclodextrin inclusion compound is prepared; the preparation method comprises the following steps: reacting hydroxyethyl cellulose with methacrylic anhydride to prepare double-bond modified cellulose; carrying out hydrothermal reaction on titanium sulfate, the carboxylated multi-walled carbon nanotube, ammonium fluoride and cerous nitrate to prepare a co-doped titanium dioxide / carbon nanotube; coating the co-doped titanium dioxide / carbon nano-tubes with oleic acid to prepare modified nano-particles; and reacting the double-bond modified cellulose with the cyclodextrin inclusion compound, and then copolymerizing with the modified nanoparticles and the comonomer to obtain the plant-based deodorant. The prepared plant-based deodorant has the advantages of good deodorization effect, slow release and photocatalytic degradation.

The invention provides porous alumina ceramic and a preparation method thereof, and relates to the technical field of ceramic materials. The invention relates to a preparation method of porous alumina ceramic. The preparation method comprises the following steps: dispersing alpha-cellulose powder in deionized water to form a cellulose suspension; stirring to fully swell the cellulose and form uniform gel, and freeze-drying to obtain a template; dissolving aluminum nitrate hexahydrate, magnesium nitrate hexahydrate and yttrium nitrate hexahydrate in absolute ethyl alcohol to obtain a precursor solution; putting gamma-Al2O3 micro powder and ammonium fluoride into a ball milling tank, adding the precursor solution and a dispersing agent, adding zirconium oxide balls and absolute ethyl alcohol into the ball milling tank, and performing ball milling to obtain ceramic slurry; dipping a template into the ceramic slurry, and performing dipping treatment under a vacuum condition to form a composite green body; and sintering to obtain the porous alumina ceramic. According to the porous aluminum oxide ceramic, the process stability is improved, and the problem that the strength is sharply reduced when the porosity is too high is solved.

The application discloses a kind of microspheroidal high-entropy spinel type ferrite wave-absorbing materials and preparation method thereof, belong to electromagnetic wave absorbing material technical field, the preparation method includes with the designed molar ratio six metal nitrate is weighed and dissolved in deionized water, then add ammonium fluoride, urea, after stirring, the obtained solution is hydrothermal reaction at a certain temperature for a certain time to obtain precursor, the precursor is calcined to obtain microspheroidal high-entropy spinel type ferrite.The obtained wave-absorbing material is single-phase spinel structure, micron-sized spherical morphology, its chemical formula is MFe2O4;Wherein M=Co, Ni, Cu, Zn, Cr.The microspheroidal high-entropy spinel type ferrite wave-absorbing material and preparation method thereof are used, and the performance of pure ferrite wave-absorbing material can be effectively improved, with the characteristics of simple preparation, strong absorption performance, absorption frequency bandwidth.

The invention relates to the technical field of etching solutions, and particularly discloses an etching solution for inhibiting etching of metallic titanium and application of the etching solution. The etching solution contains hydrofluoric acid, ammonium fluoride, an additive 1 and an additive 2; wherein the additive 1 is a fluorine capture type inhibitor, and the additive 2 is a surface adsorption type organic protective agent. The etching solution can effectively inhibit the corrosion of a titanium layer while keeping the high etching rate of silicon oxide, obviously improves the etching selection ratio of silicon oxide to titanium, has lower surface tension and higher uniformity, and is suitable for a wet etching scene with a complex structure. The additive 1 captures free fluorine ions through complexation or precipitation, the activity of the fluorine ions is reduced, and therefore the chemical attack on the titanium surface is reduced; and the additive 2 can form a transient adsorption protective film on the titanium surface to further delay the dissolution of titanium. The synergistic effect of the two additives can effectively inhibit titanium corrosion and maintain high etching efficiency.

The invention relates to the field of catalyst preparation and application thereof, in particular to a preparation method and application of zirconium dioxide catalysts with different crystal phases, a zirconium precursor and P123 are dissolved in deionized water, then ammonia water is added, and then the mixture is subjected to oil bath, product filtering and washing; and drying and then roasting to obtain tetragonal phase ZrO2. The preparation method comprises the following steps: dissolving a zirconium precursor and yttrium nitrate in deionized water, adding citric acid, adding ammonia water, carrying out oil bath, drying, and roasting to obtain cubic phase ZrO2; the preparation method comprises the following steps: dissolving a zirconium precursor in deionized water, adding ammonium fluoride, stirring, carrying out a hydrothermal reaction, cooling, carrying out centrifugal washing, drying, and roasting in a muffle to obtain the monoclinic phase ZrO2. Compared with a traditional metal supported catalyst, the problems of metal sintering, agglomeration, loss and the like are avoided. Therefore, the prepared ZrO2 catalyst with different crystal phases is an effective catalyst.

The invention discloses a ruthenium-loaded nickel-cobalt oxide heterostructure electrocatalyst and a preparation method thereof.The preparation method of the ruthenium-loaded nickel-cobalt oxide heterostructure electrocatalyst comprises the steps that nickel nitrate hexahydrate, cobalt nitrate hexahydrate, ammonium fluoride and urea are dissolved in deionized water and stirred for 30 min, the mixture and carbon cloth are subjected to a hydrothermal reaction, cleaning, drying and calcination are conducted, and the ruthenium-loaded nickel-cobalt oxide heterostructure electrocatalyst is obtained; forming a second intermediate product; ruCl3.xH2O and KCl are added into H2O, magnetic stirring is conducted for 30 min, and a second process solution is obtained; and performing electrochemical deposition of ruthenium on the second intermediate product through cyclic voltammetry to obtain a third intermediate product, and drying the third intermediate product to obtain the ruthenium-loaded nickel-cobalt oxide heterostructure electrocatalyst. According to the preparation method of the ruthenium-loaded nickel-cobalt oxide heterostructure electrocatalyst provided by the embodiment of the invention, the proportion of ruthenium in the product is more easily regulated and controlled, so that the optimal nitrate electrocatalysis reduction performance is obtained.

The invention provides a nitrogen-fluorine double-element doped porous carbon material, a silicon-carbon negative electrode material and a preparation method thereof, and the preparation method of the porous carbon material comprises the following steps: mixing porous carbon with ammonium fluoride and / or ammonium bifluoride, and carrying out vapor deposition coating or liquid phase coating; and calcining the coated porous carbon material in a closed environment in an inert atmosphere to obtain the nitrogen-fluorine double-element doped porous carbon material. According to the invention, by utilizing the characteristics of nano-scale micropores and super-large specific surface of porous carbon and the properties of low melting point and low boiling point of ammonium fluoride and ammonium bifluoride, a uniformly coated ammonium fluoride and ammonium bifluoride coating layer is obtained by adopting a vapor deposition or liquid phase coating method, and then the porous carbon material is obtained by utilizing high-temperature calcination treatment. According to the present invention, the characteristics of high specific surface and nano-scale micropores can be simultaneously retained, and after the silicon-carbon negative electrode material is prepared, the expansion of the silicon-carbon negative electrode material is substantially reduced, the cycle performance of the material is ensured, and the rate capability of the obtained silicon-carbon negative electrode material is improved.

The invention discloses a preparation method and application of a high-entropy layered double hydroxide oxygen evolution catalyst, and relates to the field of oxygen evolution reaction catalysis, and the preparation method comprises the following steps: S1, washing foamed nickel in absolute ethyl alcohol and deionized water, and then carrying out ultrasonic treatment in a hydrochloric acid solution to obtain pretreated foamed nickel; s2, adding ferric salt, cobalt salt, nickel salt, manganese salt, zinc salt and a proper amount of urea into deionized water, then adding ammonium fluoride, and uniformly stirring to obtain a mixed solution; and S3, transferring the mixed solution and the pretreated foamed nickel into a reaction kettle, carrying out a hydrothermal reaction, and washing and drying the obtained product to obtain the high-entropy layered double hydroxide oxygen evolution catalyst. According to the method, the key regulation and control effect of NH4F on the structure, chemical and electro-catalytic properties of HELDHs in the synthesis process of the HELDHs is analyzed, and the performance enhancement is attributed to NH4F-induced morphology and crystal engineering and catalytic active cation vacancies generated in situ through selective leaching of Zn < 2 + > and adsorption of sulfate under the alkaline condition.

The invention discloses a preparation method and application of double-doped biochar, and belongs to the technical field of biochar preparation, and the preparation method comprises the following steps: cleaning, drying and crushing apple branches to obtain branch powder with uniform particles; uniformly blending the branch powder, urea and potassium formate with deionized water, drying, and carrying out calcination reaction at 600-800 DEG C; cooling to room temperature, sequentially washing with diluted hydrochloric acid and deionized water until the pH is constant, and drying to obtain N-doped biochar; and uniformly blending the N-doped biochar and ammonium fluoride by using deionized water, drying, and carrying out calcination reaction at 400-600 DEG C to obtain the double-doped biochar. Compared with single N doping, the preparation method of the N and F double-doped biochar provided by the invention can more efficiently regulate and control pore development of the biochar, the step-by-step preparation method can accurately regulate and control the introduction effect of doped elements, the specific surface area of the prepared N and F double-doped biochar is greatly increased, and the preparation method is suitable for large-scale industrial production. And a sufficient structure bearing foundation is provided for the high-efficiency adsorption performance of the material.

This invention relates to a method for preparing carbon materials based on in-situ surface fluoride modification, comprising the following steps: ① dissolving carbon material powder, aluminum nitrate, and polyvinyl alcohol in anhydrous ethanol to obtain an aluminum nitrate solution; ② dissolving ammonium fluoride in a mixed solvent to obtain an ammonium fluoride solution; slowly adding the ammonium fluoride solution dropwise to the aluminum nitrate solution to carry out an in-situ AlF3 growth reaction to obtain a composite material precursor; ③ drying the composite material precursor and then calcining it using a programmed temperature rise method to solidify the coating layer, thereby obtaining the AlF3@C composite material. This invention also discloses the application of this carbon material. The preparation method of this invention is simple and low-cost, and can efficiently prepare AlF3@C composite materials. The obtained AlF3@C composite material, as a negative electrode material for potassium-ion or lithium-ion secondary batteries, can significantly improve a series of properties such as the initial coulombic efficiency, rate performance, cycle stability, and potassium ion diffusion kinetics of the battery.

The application provides a preparation method of a zeolite adsorbent, comprising the following steps: a) treating a zeolite in an oxalic acid solution, and drying to obtain a zeolite precursor; b) treating the zeolite precursor obtained in the step a) in an ammonium fluoride solution, and drying to obtain a zeolite adsorbent. The application also provides a zeolite adsorbent and an ammonia adsorption method. The preparation method provided by the application is mild and controllable in structure adjustment, and the zeolite is post-treated to make the zeolite framework selectively rearrange or slightly adjust in local areas, so that mesoporous channels with appropriate sizes and good connectivity are generated. The preparation method provided by the application can introduce mesopores while maintaining the integrity of the microporous framework structure as much as possible, avoids damage to the micropores or collapse of the framework, and has the characteristics of simple process route, wide range of control parameters, good repeatability and suitability for large-scale preparation.

The invention relates to a method for green recovery of lithium and fluorine in lithium-rich aluminum slag and preparation of battery-grade lithium dihydrogen phosphate and electronic-grade ammonium fluoride, and belongs to the technical field of comprehensive utilization of mineral resources. The method comprises the following steps: crushing and levigating lithium-rich aluminum slag obtained by electrolytic aluminum, adding deionized water, and then carrying out wet ball milling to obtain lithium-rich aluminum slag slurry; adding the lithium-rich aluminum slag slurry into a eutectic solvent for leaching, and carrying out suction filtration to obtain a leaching solution and insoluble slag; slowly dropwise adding ammonia water into the leachate, and filtering to obtain a neutralized solution and a precipitate; injecting the neutralization solution into a selective ion exchange column to obtain selective exchange resin enriched with lithium ions and ion exchange effluent; and eluting the lithium-rich resin with an H2C2O4 solution and preparing battery-grade lithium dihydrogen phosphate, and preparing electronic-grade ammonium fluoride from ion exchange effluent. According to the method, the production cost is effectively reduced through the modes of optimizing the process, reducing the energy consumption and the like, and maximization of economic benefits is achieved while the product competitiveness is improved.

A preparation method of a clean aluminum-vanadium alloy based on external electric ignition comprises the following steps that vanadium pentoxide, vanadium trioxide, metal aluminum and ammonium fluoride are mixed, ultrasonic treatment is conducted, and then vacuum treatment is conducted; and adding the obtained mixture into a preheated reactor, electrifying and igniting for reaction, and performing aging treatment after the reaction is completed, so as to obtain an aluminum-vanadium alloy product. According to the aluminum-vanadium alloy, the mass percentage of V is larger than or equal to 80%; the sum of the mass percentages of C, Si, Fe, P, S, B, O, N, H and unavoidable impurities is smaller than or equal to 0.2%.

The application relates to a substrate with micro-nano composite texture and a preparation method and application thereof, and belongs to the technical field of biological medicine. The preparation method comprises the following steps: S1, adopting a nanosecond laser to perform texture treatment on pretreated metal titanium, forming micro texture on the surface of the metal titanium, and obtaining micro texture metal titanium; S2, uniformly stirring ammonium fluoride in ethylene glycol, then uniformly stirring water in the ethylene glycol, and obtaining an electrolyte; S3, connecting the positive pole of a direct current power supply to the micro texture metal titanium as an anode, connecting the negative pole of the direct current power supply to a platinum electrode as a cathode, and performing magnetic field assisted anodic oxidation treatment on the micro texture metal titanium in the electrolyte, so that nano texture is formed on the surface of the micro texture metal titanium; and after cleaning and drying, a substrate with micro-nano composite texture is obtained. The substrate is applied to a drug-loaded coating of a metal implant, can realize micro-nano multi-scale cooperation, integrates the macrostructure advantage of the micron texture and the surface characteristics of the nanotube, and greatly improves the comprehensive performance of the drug-loaded coating.

This invention discloses an acetic acid-modified inorganic composite gel material and its preparation method, belonging to the field of organic material synthesis technology. The acetic acid-modified inorganic composite gel material comprises the following materials in parts by weight: 0.2-0.4 parts of acetic acid-Co3O4, 1.5-2.5 parts of acrylamide, 1-1.5 parts of glycerol, 0.05-0.1 parts of N-N-dimethylformamide, 0.25-0.5 parts of ammonium persulfate, 0.1-0.15 parts of sulfonated-Bi2O3, 0.6-0.9 parts of ethylenediamine, and 0.2-0.4 parts of PVP; the acetic acid-Co3O4 comprises materials in the following mass ratio: acetic acid:cobalt nitrate:thiourea:ammonium fluoride:sodium bicarbonate = 3-7:1.5-2.5:0.8-1.2:0.5-1:6; the sulfonated-Bi2O3 comprises materials in the following mass ratio: Bi2O3:sodium sulfite:H2O2:ammonium bicarbonate = 3-5:0.2-0.6:1-1.5:1. This material achieves efficient and stable catalysis for nitrogen reduction under mild conditions through structural defect regulation, interfacial functional group modification, heterojunction electronic regulation, and synergistic enhancement with organic gel.

The present invention relates to an etching solution for an active metal solder, which is used to etch an active metal solder layer containing Ag, Cu, and an active metal, and which contains ammonium fluoride, borohydrofluoride acid, and one or two elements selected from the group consisting of hydrogen peroxide and ammonium peroxydisulfate.

The invention discloses a method for preparing high-density yttrium oxyfluoride ceramic by combining a hydrothermal method and hot pressed sintering. The method comprises the following steps: (1) respectively preparing a yttrium nitrate (Y (NO3) 3.6 H2O) solution and an ammonium fluoride (NH4F) solution; (2) mixing the raw materials, and stirring for 10 to 20 minutes; (3) adding a sodium hydroxide solution into the mixed solution to adjust the pH value of the system to 10-12, and continuously stirring for 10-20 minutes to obtain a premixed solution; (4) transferring the premixed solution into a hydrothermal kettle, and carrying out hydrothermal reaction under a high-temperature condition; (5) carrying out centrifugal separation and drying treatment on the hydrothermal reaction product to obtain a yttrium oxyfluoride precursor; (6) calcining the precursor in a muffle furnace in an air atmosphere; and (7) carrying out hot pressed sintering on the obtained powder under the conditions of 750-1000 DEG C and 20-40 MPa, and carrying out heat preservation for 30-90 minutes. The obtained ceramic has high compactness and excellent plasma etching resistance.

This invention discloses a transition metal phosphide catalyst, its preparation method, and its application, belonging to the field of electrocatalysis technology. The process includes: firstly, dissolving nickel salt, lanthanum salt, urea, and ammonium fluoride in deionized water to synthesize a nickel-lanthanum layered hydroxide nanosheet precursor via a hydrothermal method; secondly, preparing a lanthanum-doped nickel phosphide catalyst using a phosphating reaction; and thirdly, utilizing a lanthanum doping strategy to modulate the electronic structure of nickel phosphide and improve its electrocatalytic reaction performance. This lanthanum-doped nickel phosphide material exhibits good catalytic activity when used to catalyze hydrogen evolution and sulfide ion oxidation reactions. In an integrated two-electrode electrolyzer for sulfide ion oxidation-assisted hydrogen production, it outputs 10 mA cm⁻¹. ‑2 This invention achieves the goal of producing hydrogen and high-value-added sulfur products with low energy consumption by requiring a relatively low voltage of 0.525 V at a current density. It has advantages such as simple preparation process, controllable operating conditions, and low raw material costs, possessing the potential for large-scale production and serving as a high-performance catalyst for electrocatalytic hydrogen production and sulfur ion oxidation reactions.

The invention discloses a preparation method of sodium fluorosulfate, which comprises the following steps: mixing sodium pyrosulfate and ammonium fluoride in an aprotic polar solvent, and reacting at 50-200 DEG C to generate sodium fluorosulfate; after the reaction is finished, separating to obtain a solution containing sodium fluorosulfate; concentrating the solution, and adding an anti-solvent to induce sodium fluorosulfate crystallization; and separating to obtain sodium fluorosulfate. According to the invention, safe and easily available ammonium fluoride and sodium pyrosulfate are adopted as raw materials, one-step reaction is carried out in a mild aprotic polar solvent system, and an anti-solvent crystallization process is combined, so that efficient preparation of sodium fluorosulfate with high purity, low acid value and no chloride ion residue is successfully realized; and the problems of dependence on high-risk raw materials and serious pollution of byproducts in the prior art are solved.

The application belongs to the technical fields of functional material preparation, catalysis and transition metal complex material, and discloses a selenium compound heterojunction catalyst coupled with hydrogen evolution, a method and application. In preparation, a cobalt source, urea, a foamed nickel and an ammonium fluoride mixed solution are mixed in a reaction, and after being hydrothermally synthesized and cooled to room temperature, the precursor Co(OH)2 / NF is obtained by washing with ethanol and water and drying. Then, selenium powder and a strong base are added into a reaction kettle, and heating is performed to obtain the heterojunction catalyst NiSe@CoSe2 / NF with high density. The obtained heterojunction material can be used for electrocatalysis of 5-hydroxymethylfurfural. When the current density is 10 mAcm ‑2 , the potential is 1.29 V, and the optimal conversion rate is more than 98%, and the catalyst has excellent catalytic activity for electrocatalysis of 5-hydroxymethylfurfural oxidation.

The invention discloses an iron fluoride / iron cyanamide and carbon coating layer composite electrode material and a preparation method thereof, and the method comprises the steps: 1, firstly adding ammonium fluoride into deionized water, fully and uniformly dissolving to obtain a solution A, and then adding hydrazine hydrate into the solution A to obtain a solution B; 2, adding FeNCN into the solution B, adding ammonia water to adjust the pH value to 6-10, stirring, carrying out suction filtration, and separating out a precipitate to obtain a sample F-FeNCN-1; 3, the sample F-FeNCN-1 is put into a tubular furnace, argon is introduced into the tubular furnace, the temperature is raised to 320-380 DEG C from the room temperature at the temperature raising rate of 10-15 DEG C / min, heat preservation is conducted for 30 min, and a sample F-FeNCN-2 is obtained; and 4, grinding a sample F-FeNCN-2, continuously putting the ground sample F-FeNCN-2 into the tubular furnace, introducing argon into the tubular furnace, heating from room temperature to 450-500 DEG C at a heating rate of 10-15 DEG C / min, and preserving heat for 30 minutes to obtain the ferric fluoride / iron cyanamide and carbon coated composite electrode material which has the advantages of high conductivity, stable interface, small volume expansion, high capacity and long cycle life.

This invention discloses a NiAlEu-LDHs photocatalyst, its preparation method, and its application in catalytic CO2 synthesis of syngas, belonging to the field of catalyst preparation technology. The NiAlEu-LDHs photocatalyst is a europium-doped layered double hydroxide prepared by a hydrothermal reaction using nickel, aluminum, and europium sources, possessing a multi-level nanoflower-like structure assembled from nanosheets. The preparation method includes the following steps: a one-step hydrothermal method is used to dissolve the nickel, aluminum, and europium sources, along with urea and ammonium fluoride, in deionized water; the solution is then transferred to a polytetrafluoroethylene-lined autoclave for hydrothermal reaction. This invention introduces europium through a one-step hydrothermal method, constructing a europium-doped nanoflower-like NiAlEu-LDHs photocatalyst. In production applications, this invention's preparation method is simple and novel, with low synthesis cost, easy mass production, and significant application value.

The invention discloses a preparation method and application of an H-Fe3O4 (at) C nanorod electrode material with a core-shell structure. Dissolving iron nitrate nonahydrate, urea, ammonium fluoride and other drugs in ultrapure water, immersing the carbon fiber cloth in the precursor solution, and carrying out a hydrothermal reaction; after the reaction is completed, cooling to room temperature, washing and sintering to obtain a Fe3O4 nanorod taking the carbon fiber cloth as the substrate; putting the Fe3O4 nanorod serving as a working electrode into a deposition solution of potassium chloride and a pyrrole monomer, and carrying out a constant-pressure deposition reaction; after deposition is completed, washing and sintering are carried out, and the Fe3O4 (at) C core-shell nanorod is obtained. And finally, carrying out rapid Joule heat treatment to further graphitize the carbon layer, cooling, and taking out to obtain the H-Fe3O4 (at) C nanorod. The H-Fe3O4 (at) C nanorod is used as a negative electrode to assemble the asymmetric supercapacitor, the capacitance retention rate of the supercapacitor is 93.7% after 25000 cycles of charge and discharge, the capacitance retention rate is far higher than that of most current pseudocapacitance supercapacitors, and the self-discharge rate of the capacitor is inhibited while good electrochemical stability is achieved.

This invention provides a method for producing high-purity aluminum-niobium-tantalum master alloys and co-producing ammonium fluoride, belonging to the fields of metallic materials and inorganic chemicals. The invention involves mixing fluoroniobic acid, fluorotantalic acid, and ammonia water for a precipitation reaction to obtain a precipitate and an ammonium fluoride solution. The ammonium fluoride solution is then concentrated, cooled for crystallization, dehydrated, and dried sequentially to obtain ammonium fluoride. The precipitate is then dried and oxidized and calcined sequentially to obtain an oxide. The oxide, aluminum powder, potassium chlorate, and calcium fluoride are mixed and subjected to a vacuum aluminothermic reaction to obtain the high-purity aluminum-niobium-tantalum master alloy. This invention, considering both broadening the range of raw material selection and optimizing the production process, reacts fluoroniobic acid, fluorotantalic acid, and ammonia water to produce niobium hydroxide and tantalum hydroxide precipitates, which are then oxidized and calcined to form niobium and tantalum oxides. The high-purity aluminum-niobium-tantalum alloy is then prepared using a vacuum aluminothermic reaction. Simultaneously, ammonium fluoride can be co-produced, resulting in high raw material utilization.

This application relates to a copper-aluminum brazed terminal block and its manufacturing method, belonging to the field of power fittings technology. It consists of an aluminum-based terminal block with a copper sheet welded to it. The flux used in the welding is a high-performance, non-corrosive copper-aluminum flux composed of the following components: potassium fluoroaluminate, cesium ammonium fluoride, 1-butyl-3-methylimidazolium tetrafluoroborate, potassium fluorotitanate, and nano-copper oxide. The process involves chemically stripping the dense alumina film using highly active fluorine species released from a pure fluorinated ionic liquid, achieving film removal and avoiding the thermal effects of high temperatures. Secondly, a nano-titanium transition layer is generated in situ through a liquid-phase displacement reaction of potassium fluorotitanate on the nascent aluminum surface, achieving a qualitative change in joint strength from mechanical interlocking to intrinsic metallurgical bonding. Finally, the elimination of chlorine and the presence of a self-cleaning mechanism prevent the flux from absorbing moisture and hydrolyzing or causing electrochemical corrosion, thus ensuring long-term reliability and durability of the joint under harsh environments while achieving good connection performance.

The application discloses a single-phase NiCoFe-LDH electrocatalyst, preparation of an electrode and application thereof. The application provides a hydrothermal synthesis method, in which pretreated nickel foam is immersed into a precursor solution containing a nickel source, a cobalt source, an iron source, urea and ammonium fluoride, and a catalyst is directly grown in situ on the substrate under controllable temperature. The core of the method is to control the total concentration of metal ions to be 30-35 mmol / L and the molar ratio to be (1-2):(1-2):(1-2), and to realize uniform compounding of nickel, cobalt and iron at an atomic scale by the synergistic effect of urea and ammonium fluoride, so that the generation of adverse impurities such as iron-rich or cobalt-rich is effectively avoided. The prepared catalyst is firmly combined with the substrate, exhibits high catalytic activity, low overpotential and excellent long-term stability in an alkaline oxygen evolution reaction, and is suitable for a high-efficiency water electrolysis hydrogen anode. The application has simple process, good reproducibility and large-scale production potential.

The utility model provides a wafer cleaning device, which belongs to the field of semiconductor equipment, and can effectively heat a liquid supply piece through the arrangement of a heating piece, thereby effectively preventing the formation of ammonium fluoride crystals. Due to the arrangement of the temperature detection piece and the controller, the temperature can be automatically and conveniently controlled; through the arrangement of the cooling part, rapid cooling of the liquid supply part / the liquid supply part shell can be achieved, and aging is improved; due to the arrangement of the passivation layer, reaction between ammonium fluoride crystals and metal materials can be avoided, and the probability of generation of metal impurities is reduced; by arranging the liquid supply piece shell, the liquid supply piece can be effectively protected, and reaction between the liquid supply piece and ammonium fluoride crystals is avoided; and the heat insulation piece is arranged, so that the influence of heat on the cleaning liquid in the liquid supply piece can be avoided, and ammonium fluoride crystals are effectively prevented from being generated in time. The wafer cleaning device provided by the utility model can improve the time efficiency, and can improve the productivity and quality of products.

The invention relates to the technical field of aluminum soldering flux, and particularly discloses flux core soldering flux for an aluminum brazing tin wire and a preparation method and application of the flux core soldering flux. The flux core soldering flux for the aluminum brazing tin wire comprises the following components in parts by mass: 15 to 25 parts of ammonium salt, 53 to 64 parts of triethanolamine, 10 to 19 parts of zinc citrate, 1 to 8 parts of stannous salt, 0.4 to 1.2 parts of fluorine surfactant, 0.5 to 2 parts of corrosion inhibitor and 0.1 to 0.8 part of defoaming agent. The amine salt is a compound of ammonium fluoride, ammonium fluoborate and ammonium dihydrogen phosphate. The method has the advantage of improving the aluminum material welding quality.

The invention discloses a synthesis process of tungsten hexafluoride, and relates to the technical field of special gas synthesis. The process comprises the following steps: mixing ammonium fluoride and hydrofluoric acid to prepare an activation solution, carrying out ultrasonic activation treatment on tungsten powder to obtain pretreated tungsten powder, and reacting the pretreated tungsten powder with fluorine gas at a certain temperature and pressure to prepare a liquefied crude product tungsten hexafluoride; the preparation method comprises the following steps: by taking aluminum sec-butoxide and the like as raw materials, carrying out sol-gel and ethanol supercritical drying and calcining to prepare highly porous activated aluminum oxide; gasifying the crude tungsten hexafluoride, adsorbing with activated aluminum oxide, and rectifying to obtain purified tungsten hexafluoride liquid; and finally, dissolving in liquid sulfur dioxide, treating under illumination with the wavelength of 395nm, and carrying out distillation separation to obtain high-purity tungsten hexafluoride. According to the method, the activation pretreatment is combined with multi-stage purification, so that the purity and the synthesis efficiency of tungsten hexafluoride are remarkably improved.

The invention relates to the technical field of energetic material synthesis, and particularly provides 5, 5 '-azotetrazole salt and a preparation method thereof.The preparation method comprises the following steps that 1, pretreated carbon cloth is immersed in a mixed solution formed by dissolving cobalt nitrate hexahydrate, ammonium fluoride and urea in deionized water, after a hydrothermal reaction, the carbon cloth is taken out and calcined in the air atmosphere, and a precursor is obtained; and finally, the cobaltosic oxide electrode material loaded on the carbon cloth is prepared. 2, dissolving 5-aminotetrazole in an alkaline solution to prepare an electrolyte, forming a three-electrode system by taking the electrolyte and cobaltosic oxide loaded on carbon cloth as a working electrode, a platinum sheet as a counter electrode and a mercury / mercuric oxide electrode as a reference electrode, and electrifying to carry out electrochemical reaction; 3, bromine water is dropwise added into the three-electrode system in the electrifying electrolysis process, hydrochloric acid is dropwise added to adjust the pH value after the reaction is finished, extraction and rotary evaporation are conducted, and the final product 5, 5 '-azotetrazole salt is obtained.