10 results about "Tungstate ion" patented technology

The invention belongs to the technical field of fluorine-containing fine chemicals, and particularly relates to a method for catalytically synthesizing perfluoroepoxide by using tungstate ionic liquid. Comprising the following steps: mixing hexafluoropropylene dimer, tungstate ionic liquid, a cocatalyst and hydrogen peroxide in a reactor, and stirring for reaction to prepare perfluoroepoxide; the anion of the tungstate ionic liquid is [WO4] < 2->. According to the method, the tungstate ionic liquid is used as a catalyst and a solvent, hydrogen peroxide is used as an oxidizing agent, a large amount of organic solvent does not need to be additionally added, the method is green and environment-friendly, the tungstate ionic liquid can be recycled, and the production cost is remarkably reduced; by designing the structures of the zwitterions of the tungstate ionic liquid, high conversion rate of raw materials and high selectivity of target products can be realized, and the tungstate ionic liquid has a wide market prospect.

The invention relates to a perovskite quantum dot capable of improving luminous intensity through light driving and a preparation method thereof, the perovskite quantum dot comprises a micro / mesoporous template and perovskite nanocrystals located in pore channels of the micro / mesoporous template, and tungstate ions are loaded in the pore channels of the micro / mesoporous template; under the irradiation of blue light, B-site metal cations in the perovskite nanocrystals react with tungstate ions to form a BWO4 passivation layer. According to the invention, the formation of the BWO4 passivation layer in the micro / mesoporous template is driven by blue light illumination, and the surface defects of the perovskite quantum dots are passivated, so that the luminous efficiency of the perovskite quantum dots is further improved.

The invention belongs to the technical field of thermal insulation coatings and photocatalytic degradation agents, and particularly relates to flaky cesium tungsten bronze powder and application thereof. The cesium tungsten bronze nanosheet is prepared by using a hydrothermal method and innovatively adopting alkyl sulfate and / or sulfonate and / or alkyl sulfonate and / or sulfate and / or disulfate as a morphology control agent. According to the method, a proper amount of stabilizer with a proper concentration is introduced, tungstate ions are compelled to be chelated with dissociated carboxyl, a relatively stable tungstate complex is formed in an acid solution, and the yield of the nano-sheet cesium-tungsten bronze can be increased as much as possible by matching with a shape control agent with a proper type and a proper concentration. The preparation process is simple and controllable, and the obtained product can be used for preparing a water-based transparent heat-insulating coating or film or used as a photocatalytic degradation agent. The infrared light shielding rate of the prepared film is greater than 95%. When the product is directly used as a photocatalytic degradation agent, the photocatalytic degradation efficiency and performance of the product are extremely excellent.

The present invention belongs to the technical field of tungsten metallurgy, and particularly relates to a flocculent spherical nano tungsten acid, a preparation method thereof and an application. The preparation method includes: S1. Add hydrochloric acid into a container, continuously stir during the addition process and keep the temperature in the container stable; S2. Drop 2-5 mL of ammonium tungstate solution B into the container, continuously stir during the addition process and keep the temperature in the container stable; S3. Add 0.6-1.0 L of ammonium tungstate solution A into the container, continuously stir during the addition process and keep the temperature in the container stable; the amount of hydrochloric acid added in step S1 is 1.5-2.0 times the theoretical amount of hydrochloric acid required for preparing tungstic acid according to the tungstate ion concentration in ammonium tungstate solution A; S4. Repeat steps S1 and S3; S5. Filter the prepared tungstic acid, wash it with hydrochloric acid and then dry it to obtain flocculent spherical nano tungstic acid. The prepared tungstic acid has good grain uniformity and is in a flocculent spherical shape, has porous characteristics, and the specific surface area is ≥80 m 2 / g.

The invention belongs to the field of tungsten alloy wire manufacturing, and particularly relates to a method for recovering sodium tungstate from tungsten filament alkali wash liquor, which comprises the following steps: obtaining the tungsten filament alkali wash liquor, adding activated carbon into the tungsten filament alkali wash liquor, and filtering to obtain filtrate; adding an organophosphate solvent into the filtrate, and separating out an organic phase and a water phase; removing water from the water phase to obtain a solid phase; and washing the solid phase with an alcohol solvent, and drying to obtain sodium tungstate. By utilizing the strong adsorption performance of the activated carbon, oil stains and emulsifiers in the waste alkali liquid can be effectively removed; effective separation of tungstate radicals from metal ions such as Co < 2 + >, Ni < 2 + > and Fe < 3 + > is realized by utilizing the solubility difference of the metal ions in an organic solvent and water; relatively pure sodium tungstate crystals are obtained; through simple filtration, extraction and reduced pressure distillation processes, efficient recovery of tungsten is realized, and the resource utilization efficiency is optimized.

This invention discloses a method for recovering tungsten and rhenium from tungsten-rhenium alloy waste, belonging to the field of waste metal recycling technology. The method includes: leaching pretreated tungsten-rhenium alloy waste by heating and stirring with a mixed solution of dilute hydrochloric acid and hydrogen peroxide, converting tungsten and rhenium into tungstate ions and perrhenate ions respectively into the solution; then, rapid acidification by quantitatively adding concentrated hydrochloric acid, causing tungsten to precipitate as crystalline tungstic acid; filtering to obtain a crystalline tungstic acid filter cake and a rhenium-containing filtrate; adsorbing the rhenium-containing filtrate through an anion exchange resin to load perrhenate ions onto the resin; subsequently eluting with an ammonia solution to obtain an ammonium perrhenate solution; evaporating, concentrating, and crystallizing to obtain ammonium perrhenate crystals; simultaneously washing and drying the tungstic acid filter cake to obtain the tungstic acid product. This invention features a simple process flow, thorough tungsten-rhenium separation, high recovery rate, is green and economical, and can obtain high-purity tungsten and rhenium products.

The invention provides a preparation method of a nickel-iron-tungsten oxygen evolution electrode, and belongs to the technical field of hydrogen energy. The method comprises the following steps: by taking a nickel-iron alloy matrix as a working electrode, carrying out electrochemical oxidation-reduction activation treatment at room temperature in a mixed solution of tungstate, nitrate and chloride, and then carrying out heat treatment on the nickel-iron alloy matrix. In the electrochemical oxidation process, nickel ions and iron ions are dissolved out of the nickel-iron alloy matrix, meanwhile, electrochemical oxidation of chloride ions is carried out to form active chlorine, and the nickel ions and the iron ions are further chemically etched out; in the electrochemical reduction process, nitrate radicals and water on the electrode are reduced to generate hydroxyl radicals; in the process, nickel and iron ions on the electrode are combined with tungstate radicals and hydroxyl radicals to form a nickel-iron-tungsten composite hydroxide; and a nickel-iron-tungsten composite oxide is formed in the subsequent heat treatment process, so that the oxygen evolution activity and stability are further improved.

The present invention belongs to the technical field of tungsten metallurgy, and particularly relates to a nano tungsten acid with a multi-stage structure and a preparation method thereof. The preparation method includes: S1. Add hydrochloric acid to a container, and continuously stir during the addition process to keep the temperature in the container stable; S2. Drop 2-5 mL of a sodium tungstate-ammonium tungstate mixed solution B into the container, and continuously stir during the addition process to keep the temperature in the container stable; S3. Add 50-200 mL of a sodium tungstate-ammonium tungstate mixed solution A to the container, and continuously stir during the addition process to keep the temperature in the container stable; the amount of hydrochloric acid added in step S1 is 2.2-2.6 times the theoretical amount of hydrochloric acid required to prepare tungstic acid according to the tungstate ion concentration in the sodium tungstate-ammonium tungstate mixed solution A; S4. Repeat steps S1 and S3; S5. Filter the prepared tungstic acid, wash it with hydrochloric acid, and then dry it to obtain a nano tungsten acid with a multi-stage structure. The nano tungsten acid with a multi-stage structure includes massive tungstic acid and flocculent tungstic acid, and the specific surface area is 50-75 m<supgt;2< / supgt> / g.

This invention discloses a method for controlling tungsten release from sediments using lanthanum-modified red clay, belonging to the field of sediment pollution control and water remediation technology. The invention uses natural red clay as raw material, reacting it with lanthanum chloride hexahydrate at room temperature to prepare lanthanum-modified red clay. This material is then uniformly applied to the surface of tungsten-contaminated sediments. Through the formation of stable lanthanum tungstate precipitates and inner spherical complexes between lanthanum ions and tungstate ions, the adsorption capacity and fixation efficiency for tungsten are significantly improved, effectively inhibiting the release of tungsten from sediments into overlying water. This invention features a simple preparation process, readily available raw materials, low cost, and environmental friendliness. The resulting stable product remains stable under reducing conditions, providing a long-lasting remediation effect. It can achieve a 56.1% fixation rate of dissolved tungsten in interstitial water of sediments, significantly reducing tungsten release flux and the content of unstable tungsten. This method is suitable for in-situ control and ecological remediation of tungsten-contaminated sediments in lakes, rivers, reservoirs, and other water bodies.

The invention discloses nano-coating modified intestinal probiotics and application thereof in treatment of inflammatory bowel disease, dopamine with excellent biocompatibility is adopted to synthesize mesoporous nanoparticles through a soft template method, and then tungsten ions are loaded through mesoporous adsorption of mesoporous polydopamine and ion exchange with tungstate ions, so that the nano-coating modified intestinal probiotics are obtained. And then forming a nano coating on the surface of the viable bacteria through the viscosity of dopamine. After oral administration, the mesoporous polydopamine nano coating wrapping the probiotics can well shield damage of severe environments such as high-level oxidative stress environment, pepsase and trypsin to the probiotics in an inflammatory environment, so that the probiotics still have relatively high biological activity after entering intestinal tracts; and meanwhile, the slowly released tungsten ions can effectively inhibit the breeding of enterobacteriaceae, so that the effects of relieving intestinal inflammation, regulating intestinal flora composition and further regulating the liver function metabolism condition are achieved.