160 results about "Vanadium doping" patented technology

A ceramic anode structure obtainable by a process comprising the steps of: (a) providing a slurry by dispersing a powder of an electronically conductive phase and by adding a binder to the dispersion, in which said powder is selected from the group consisting of niobium-doped strontium titanate, vanadium-doped strontium titanate, tantalum-doped strontium titanate, and mixtures thereof, (b) sintering the slurry of step (a), (c) providing a precursor solution of ceria, said solution containing a solvent and a surfactant, (d) impregnating the resulting sintered structure of step (b) with the precursor solution of step (c), (e) subjecting the resulting structure of step (d) to calcination, and (f) conducting steps (d)-(e) at least once.

The invention relates to a vanadium doping type titanium base fume denitration catalytic material and a preparation method thereof. The material is characterized in that a surface active agent is used as a pore structure guiding agent, a water solution system sol-gel method is used for preparing the vanadium doping type titanium base catalytic material, and the doping content of active component vanadium is 0.5 to 20wt percent measured by V2O5. Because an in-situ doping loading mode is adopted in the sol-gel process, the preparation method is simple, and the production cost is low; in addition, the prepared denitration catalytic material has larger specific surface area, higher heat stability, higher denitration efficiency and wider active temperature window, and is suitable for the field of removal of coal-fired fume nitrogen oxide. The laboratory simulation fume evaluation shows that when the air speed is 10,000/h, and under the condition that the content of NO is 1000ppm, the removal rate of NO achieves more than 95 percent at the temperature of 180 to 420 DEG C.

The invention relates to a method and device for growing a high-purity semi-insulating silicon carbide single crystal and belongs to the technical field of single crystal growth. A crucible and thermal insulation materials for growing a SiC single crystal are pre-processed by utilizing a specific device, specific gas is introduced in the single crystal growth process, the donor impurities N, acceptor impurities B and metal ions impurities in the SiC single crystal are effectively reduced, the specific resistance is enhanced, the power output of high-frequency and high-power devices is prevented from being affected by the deep capture center of vanadium-doped semi-insulating SiC, and the high-purity semi-insulating silicon carbide single crystal is obtained.

A current perpendicular to plane (CPP) giant magnetoresistive (GMR) sensor having an antiparallel coupled (AP coupled) pinned layer structure wherein the pinning layer have a greatly reduced negative contribution to dR. The pinned layer structure includes a first a first set of magnetic layers such as CoFe and a second set of magnetic layer comprising CoFeV that are antiparallel coupled with the first set of magnetic layers. The magnetic layers of the pinned layer structure alternate between a one of the first set of magnetic layers (eg. CoFe) and one of the second set of magnetic layers (CoFeV). The magnetic layers of the first set contribute to the GMR of the sensor and provide a positive magnetostriction that assists with the pinning of the pinned layer structure. The magnetic layers of the second set contribute pinning, but do not contribute to GMR. The presence of V in the second set of greatly reduces the negative contribution to dR that would otherwise be provided by these pinning layers of the second set by reducing the spin dependent electron scattering through these layers.

A sublimation grown SiC single crystal includes vanadium dopant incorporated into the SiC single crystal structure via introduction of a gaseous vanadium compound into a growth environment of the SiC single crystal during growth of the SiC single crystal.

Novel anode materials including various compositions of vanadium-doped strontium titanate (SVT), and various compositions of vanadium- and sodium-doped strontium niobate (SNNV) for low- or intermediate-temperature solid oxide fuel cell (SOFCs). These materials offer high conductivity achievable at intermediate and low temperatures and can be used as the structural support of the SOFC anode and/or as the conductive phase of an anode. A method of making a low- or intermediate-temperature SOFC having an anode layer including SVT or SNNV is also provided.

The invention provides a preparation method of vanadium doping molybdenum disulfide nanoflower with defects and electrocatalysis application thereof. Firstly, a molybdenum and sulfur pre-reaction solution is prepared, and the reaction solution is heated to synthesize defective molybdenum disulfide nano-powder; then hydrothermal reaction is carried out on the defective molybdenum disulfide nano-powder and vanadium source compound to synthesize vanadium doping molybdenum disulfide spherical nano-powder; under the protection of inert gases, annealing treatment is carried out to obtain vanadium doping molybdenum disulfide nanoflower-shaped nano-powder. Vanadium doping molybdenum disulfide with defects is applied to electrocatalysis hydrogen generation reaction (HER), the catalytic performanceis excellent, the overpotential is as low as -0.160V (relative standard hydrogen electrode), and the Tafel slope is as low as 46mV/dec.

The invention belongs to the field of semiconductor devices and relates to an opposite electrode structure, an SiC photoconductive semiconductor switch (PCSS) and manufacturing methods thereof. The opposite electrode structure comprises a semi-insulating SiC wafer, a hollow electrode post, a semitransparent or transparent electrode layer and a solid electrode post, wherein the semi-insulating SiC wafer is a high-purity semi-insulating or vanadium doped semi-insulating SiC wafer which is subjected to polishing treatment; the semitransparent or transparent electrode layer is an Au (500nm)/Pt (100nm)/Ti (100nm)/Ni (50nm) semitransparent electrode structure or a transparent conducting thin film, and the Au (500nm)/Pt (100nm)/Ti (100nm)/Ni (50nm) semitransparent electrode structure or the transparent conducting thin film is optionally selected for corresponding annealing; and the hollow electrode post and the solid electrode post are preferably a hollow aluminum electrode post and a solid aluminum electrode post respectively. The SiC PCSS is obtained by subjecting the opposite electrode structure to insulating package and air pumping package by using a Teflon mould. Compared with SiC photoconductive semiconductor switches in prior art, the SiC PCSS has the advantages that light pass areas can be increased, and simultaneously, high withstand voltage of the PCSS can be guaranteed.

An optically addressed light valve suitable for selectively limiting the transmission of radiation from high intensity light sources independent of wavelength using a TN liquid crystal cell and a photoconductive material (vanadium doped silicon carbide).

The invention relates to a preparation method of a vanadium-doped lithium nickel cobalt manganese oxide nanometer material. The material which can be taken as an active cathode material for lithium ion batteries is of an alpha-NaFeO2 laminated structure, and belongs to an R3m space group; the particle size of the material is 100-300 nm; and particles are stuck together. The vanadium-doped lithium nickel cobalt manganese oxide LiNi1/3Co1/3Mn1/3O2 nanometer material is prepared through the combination with a simple and practicable coprecipitation method and a solid phase sintering method; when the material is taken as the active cathode material for lithium ion batteries, the material has the characteristics of high power and good cycling stability; and secondly, the preparation method is simple in technology, a precursor slurry can be obtained through simple and practicable parallel flow feeding, and the vanadium-doped lithium nickel cobalt manganese oxide nanometer material can be obtained by carrying out centrifugal washing and drying and solid phase sintering in air atmosphere on the slurry. The method is high in practicability and easy for magnification, accords with the characteristic of green chemistry, and is beneficial for market popularization.

The invention provides a vanadium-doped silicon oxide-based mesoporous molecular sieve catalyst, as well as a preparation method and application thereof. According to the catalyst, a pure silicon mesoporous molecular sieve KIT-6 is taken as a carrier, vanadium oxide is taken as an active ingredient, and is doped into a framework of the pure silicon mesoporous molecular sieve KIT-6, and the molar ratio of V to Si is 0.1:100 to 8:100. The invention further provides the preparation method for the catalyst and the application of the catalyst to selective oxidative dehydrogenation of propane for production of olefin. According to the vanadium-doped silicon oxide-based mesoporous molecular sieve catalyst, the dispersity of the active ingredient vanadium is higher, the concentration of an active site is higher, and the stability of the active site is higher, so that the catalytic activity of the catalyst is higher. When the catalyst is applied to reaction of selective oxidative dehydrogenation of the propane for production of the olefin, the molar recovery rates of products propene and olefin of selective oxidation reaction of the propane can reach 35.6 percent and 38.6 percent respectively.

The invention discloses a preparation method of a graphene quantum dot/vanadium-doped mesoporous titanium dioxide composite photocatalyst. The catalyst disclosed by the invention is composed of a graphene quantum dot and a vanadium-doped mesoporous titanium dioxide micro-ball obtained by a solvothermal method. Under simulated sunlight, the catalyst not only can effectively mineralize methylene blue into CO2 and H2O, but also can reduce carbon dioxide generated by catalytic oxidation into a useful hydrocarbon compound. The preparation method has the advantages that 1, the energy gap of titanium dioxide is reduced by doping vanadium so that the response range of the titanium dioxide under visible light is improved; 2, photosensitization and ultra-strong electron conduction capability of the graphene quantum dot are utilized so that the compounding of photo-generated electrons and a cavity is inhibited and the utilization rate of light is also improved; and 3, raw materials are cheap and easy to obtain, a synthesis method is simple, the yield and purity of synthesis are relatively high, the experiment repeatability is good and the preparation method is suitable for requirements of enlarged production.

The invention relates to a method for preparing cyclohexanol and cyclohexanone by oxidizing cyclohexane, in particular to a method for preparing a vanadium-doped ZSM-5 molecular sieve and a catalytic property of the molecular sieve on preparation of cyclohexanol and cyclohexanone by oxidizing cyclohexane. A molar ratio of vanadium to silicon in the microporous molecular sieve is 0.02-0.03, oxygen and the like are taken as an oxidant, reaction is performed at the temperature of between 80 and 150DEG C under the pressure of between 0.5 and 2.5MPa for 1 to 10 hours, the conversion rate of the cyclohexane is 14.68 percent, and the sum of the selectivity on the cyclohexanol and the cyclohexanone is 97.3 percent. The method has the characteristic that transition metal V atoms in the V-ZSM-5 molecular sieve prepared by a direct hydrothermal synthesis method can enter the skeleton of the molecular sieve so as to greatly improve the activity and selectivity of oxidation reaction.

The invention belongs to the technical field of chemical products and preparation therefore, and specifically relates to preparation and applications of a cationic poly(quaternary ammonium salt) vanadium doped heteropolyacid supramolecular system. In the supramolecular system, poly(quaternary ammonium salt) cation is a homopolymer with a linear structure, and the homopolymer is prepared through free radical polymerization of dimethyl diallyl ammonium chloride monomers. The matched heteropolyacid anion is Dawson type vanadium doped P2Mo17VO62<-7>, P2Mo16VO62<-8>, and P2Mo15VO62<-9>. The supramolecular system is a heterogeneous catalyst, industrial hydrogen peroxide with a mass percentage of 3 to 5% is used as an oxidant, and cyclic ketone is oxidized to synthesize omega-dicarboxylic acid through one-step ring opening in the absence of solvent. The omega-dicarboxylic acid preparation method has the advantages of high catalytic activity, good selectivity, wide substrate range, friendly synthesis technology environment, mild operation conditions, large elasticity, and high product purity, and the catalytic system is reusable.

The invention belongs to the field of composite metal nano materials, and particularly relates to a vanadium-doped cobalt-iron layered double hydroxide/foamed nickel nano composite material and a preparation method thereof. According to the method, a hydrothermal synthesis method is adopted, vanadium-doped cobalt-iron layered double hydroxide grows on substrate foamed nickel at a lower temperature, and a vanadium-doped cobalt-iron layered double hydroxide/foamed nickel nanosheet array is directly obtained. The material has a sheet structure, and the structure can expose more active sites and has good stability; and moreover, foamed nickel has good conductivity, the electron migration rate is increased, and the material has good performance in electrolyzing aquatic oxygen. The vanadium-doped cobalt-iron layered double hydroxide/foamed nickel nano composite material has the advantages of simple and effective experimental conditions, high repeatability, environmental friendliness, low cost and easily available raw materials, and is expected to be applied to industrial production of high-efficiency electrocatalysts.

The invention mainly belongs to the field of photoelectrochemistry water-splitting for hydrogen production and particularly relates to a vanadium-doped ZnO nanorod array photo-anode, a preparation method of the vanadium-doped ZnO nanorod array photo-anode and an application of the vanadium-doped ZnO nanorod array photo-anode in photoelectrochemistry water-splitting for hydrogen production. The method comprises the steps of preparing a ZnO seed crystal solution, a vanadium-doped solution and a growth solution correspondingly; conducting spin-coating on conducting glass with the ZnO seed crystal solution and obtaining the conducting glass with the surface covered with a ZnO seed crystal layer after spin-coating and annealing; pulling the conducting glass with the surface covered with the ZnO seed crystal layer into a mixed solution of the vanadium-doped solution and the growth solution for a hydrothermal reaction, washing the conducting glass with deionized water after completion of the reaction, conducting annealing in a muffle furnace and then obtaining an vanadium-doped ZnO nanorod array. By adopting the vanadium-doped ZnO nanorod array photo-anode provided by the invention, the carrier life is prolonged, combination of electron holes is reduced, and the photoelectrochemistry water-splitting performance is improved.

The invention discloses a tin-oxide coated and vanadium-doped lithium iron phosphate material and a preparation method thereof. The surface of an active substance for the positive electrode of a lithium-ion battery is coated with a layer of an oxide film, the vanadium is doped for diffusion modification of irons, and the LiFe[1-x]VxPO4.ySnO which is the lithium iron phosphate positive material is synthesized by one-step reaction, wherein x is not less than 0.01 and not more than 0.05, and y is not less than 0.005 and not more than 0.05. The lithium iron phosphate positive material with a stable structure and high electrochemical activity is prepared by adopting a simple method, overcomes the technical defects of poor electrical conductivity, low tap density and poor high-temperature circulation stability of the existing lithium iron phosphate and has a strong competitive advantage in the aspects of cost control, process simplification, discharge capacity, circularity and high-current discharge capability. In addition, the lithium-ion battery composite positive material has high performance and good circulation stability.

The invention discloses a preparation method of a high-performance aluminum and potassium co-doped sodium vanadium fluorophosphate/carbon composite material. According to the preparation method, a uniform solution is formed from a reaction raw material and low-molecular polyethylene glycol, a high-activity aluminum-doped vanadium phosphate/carbon composite material is prepared by combining carbonthermal reduction reaction, and the high-performance Na<1-x>K<x>V<1-y>Al<y>PO<4>F/C composite material is obtained by high-temperature reaction under inert atmosphere by taking the aluminum-doped vanadium phosphate/carbon composite material as the raw material. Carbon with high electron conductivity is generated from polyethylene glycol and a carbohydrate under a high-temperature inert atmospherecondition in an in-situ way, carbon can generate a reduction agent in carbon thermal reduction reaction, and growth and agglomeration of product particles also can be prevented; a larger passage is provided for sodium ion mobility by sodium doped with potassium, and the structural stability of sodium vanadium fluorophosphate is improved by vanadium doped with aluminum; and by combining the advantages of high electron conductivity, large sodium ion mobility passage and structural stability, the aluminum and potassium co-doped sodium vanadium fluorophosphates/carbon composite material has excellent electrochemical performance.

The invention discloses a preparation method of a vanadium-doped tailings inorganic-foam thermal-insulation material for buildings, which comprises the following steps of dispersing vanadium tailings powder, polypropylene fibers, fly ash, common Portland cement, calcium stearate and triethanolamine in water so as to obtain non-foamed slurry; and adding hydrogen peroxide with a mass concentration of 30% into the non-foamed slurry, molding obtained pre-formed slurry by casting, and carrying out maintenance, demoulding and cutting on the obtained product so as to obtain the vanadium-doped tailings inorganic-foam thermal-insulation material for buildings. The heat transfer capability of the thermal-insulation material for buildings is reduced by over 100% in comparison with common wall bodies, so that the total thickness and total weight of a wall body can both be reduced by over 60%, thereby solving a bottleneck problem that current materials for wall bodies for housing industrialization are inconvenient to install. According to the invention, by controlling the adding amount and stirring time and strength of the hydrogen peroxide, the foaming effect is controlled, the coefficient of thermal conductivity is reduced, and the heat preservation effect is enhanced; by taking an early strength agent and an accelerator as anti-collapse agents, the rejection rate is reduced, and a novel vanadium-doped tailings inorganic-foam thermal-insulation material for buildings is prepared.

A preparation method of electrode materials for lithium batteries comprises the following steps: providing a vanadium source, iron salt and a phosphorus source and dissolving the vanadium source, the iron salt and the phosphorus source into a solvent to form mixed liquid; regulating the pH value of the mixed liquid to be 1.5-5 during mixing to ensure the mixed liquid to react so as to form vanadium-doped iron phosphate precursor particles; providing lithium source solution and a reducing agent and mixing the lithium source solution and the vanadium-doped iron phosphate precursor particles with the reducing agent uniformly to form mixed slurry; and drying and heating the mixed stock, thus forming the vanadium-doped lithium iron phosphate electrode materials.