33 results about "Vanadium(IV) oxide" patented technology

The invention provides spectrum locally-modified hot color nano-composite powder and a preparation method thereof. The powder is of a multilayer composite core-shell structure which consists of a V2O layer, a precious metal layer and a transparent oxide layer, wherein the V2O layer serves as a core layer; the precious metal layer and the transparent oxide layer are respectively positioned on the second layer or the third layer. According to the spectrum locally-modified hot color nano-composite powder and the preparation method thereof, the precious metal layer and the transparent oxide layer coat the surfaces of V2O nano-particles, so that the stability of the V2O nano-particles can be improved, the spectral characteristics of V2O nano-powder can be adjusted, and the transmission color and the reflection color of the V2O nano-powder are adjusted; therefore, the aim of improving the color of the V2O powder is fulfilled. The powder can be widely applied to the fields of heat insulation coatings, lamination and the like, can be applied to an intelligent energy-saving coating, and can also be applied to the heat insulation places of glass, outer walls and the like.

The invention relates to carbon-coated vanadium dioxide nanoparticles and a preparation method thereof. The particles consist of rutile-phase nano vanadium dioxide kernels and carbon shells covering the rutile-phase nano vanadium dioxide kernels, wherein the rutile-phase nano vanadium dioxide kernels are approximately square nanoparticles with a length-diameter ratio of being less than 3 and a three-dimensional size of being less than 100 nm; the thickness of the carbon shells are 1-10 nm; the carbon shells account for less than 20 percent by weight of the mass fraction of the particles. The preparation method comprises the following steps: synthesizing the rutile-phase vanadium dioxide nanopowder by using hydrothermal reaction; adding a carbon source into hydrothermal reaction liquid; then performing hydrothermal reaction to perform in-situ carbon coating. The carbon-coated vanadium dioxide nanopowder has superior thermochromic performance, good stability, low cost and high yield and is suitable for large-scale production. The nanopowder can be widely applied to energy-saving coatings, flexible energy-saving films or energy-saving glass of buildings and automobiles.

The invention relates to a preparation method of a vanadium dioxide nano material and application in a rechargeable magnesium battery. The vanadium dioxide nano material, of which the crystal structure is a phase B, is prepared by taking vanadium pentoxide, citric acid and a surfactant which are low in cost as raw materials and adopting a one-pot hydrothermal method; the vanadium dioxide nano material is high in purity and good in crystallization performance, and the preparation method is easy to control. When the phase-B vanadium dioxide nano material is used as a cathode material of the rechargeable magnesium battery, at the current density of 50 mA / g, the first specific discharge capacity can be up to 394.2 mAh / g; after the battery is cycled for 60 circles, the specific discharge capacity still can be kept at 205.9 mAh / g, and a discharge voltage platform reaches 2.1 V (vs.Mg<2+> / Mg), so that relatively high electrochemical magnesium removal and embedding performance is achieved.

The invention discloses a method for preparing hypovanadic oxide powder-doped material, which belongs to the production and preparation field of inorganic functional materials and relates to the preparation of hypovanaic oxide powder doped with W, Mo or W / Mo. The method comprises the following steps: mixing and evenly grinding a vanadium source, a doped raw material and an auxiliary agent, pouring the mixture after being molten at a high temperature and keeping the temperature for a certain period of time into cold water to be rapidly water-quenched, drying the formed gel to form dry gel, thermal-reducing the grinded dry gel in the reduction atmosphere, performing annealing treatment in a protective atmosphere, and realizing the crystalling phase conversion at a constant temperature so as to obtain M-phase VO2 with phase transition property. The phase transition temperature of the VO2 powder after doping can be effectively controlled by adjusting the W and Mo atom doping amount. The invention has remarkable advantage in the aspects of preparation cost, product performance, technique flow, friendly environment, economic profit, and the like, has easily available raw materials, simple and convenient synthesis, low requirement on the equipment and high product performance, is suitable for industrial production and has wide application of product.

The invention relates to a tungsten-doped vanadium dioxide powder material which comprises the following components by mass percent: 2.97-3.19 percent of reducing agent, 0-6.89 percent of industrial pure tungsten trioxide and balance industrial pure vanadium pentoxide; and the sum of the mass percent of the components is 100 percent. A preparation method of the tungsten-doped vanadium dioxide powder material comprises the steps of: first, weighing raw materials according to the mass percent, and mixing the raw materials for 4-6h; then, carrying out high temperature reduction on the evenly mixed powder under the protection of inert gas; and finally, dispersing and obtaining the tungsten-doped vanadium dioxide powder material. By adopting the tungsten-doped vanadium dioxide powder material and the preparation method thereof, vanadium dioxide is high in purity and single in crystal form, and the phase-transition temperature Tc can be controlled within the range of minus 2.9 to 67.04 DEG C according to the number of doped metal ions W6<+>, so that the optical, electrical, magnetic and other properties of the tungsten-doped vanadium dioxide powder material have mutation within the range of minus 2.9 to 67.04 DEG C, and the demand of special type functional material can be met.

The invention relates to a method of preparing vanadium dioxide by a double-temperature area reduction process. The method comprises the following steps: placing vanadium pentoxide and high-activity metal into a sealed system with negative pressure by spacing a certain distance; respectively heating vanadium pentoxide and the high-activity metal to different temperatures for thermally treating for determined time, so that oxygen partial pressure in the sealed system is lower than balanced oxygen partial pressure of vanadium pentoxide and vanadium pentoxide is reduced to obtain vanadium dioxide, wherein the high-activity metal is heated to a first temperature and vanadium pentoxide is heated to a second temperature lower than the first temperature; the heated high-activity metal reacts with oxygen gas in the sealed system to lower the oxygen partial pressure in the sealed system, so that the oxygen partial pressure of the sealed system is lower than the balanced oxygen partial pressure of vanadium pentoxide. The vanadium dioxide obtained by the method disclosed by the invention is controllable in crystalline phase and grain size, and has a morphology which is kept consistent or similar to that of a vanadium pentoxide precursor.

The invention provides a preparation method of vanadium oxide / carbon nanometer tube composite materials with interpenetrating network structures. The carbon nanometer tubes with good conductivity are adopted for self assembly with single-dimensional vanadium oxide nanometer materials on the nanometer scale, so the carbon nanometer tubes have the effects of conductive bridges between all interwoven single-dimensional vanadium oxide nanometer materials for building interpenetrating network structures under the microcosmic dimensions, and the composite material with the structure can be used as a lithium ion injection material with high capacity and high stability. The method comprises the following preparation processes: using V2O5 collosol prepared by a quenching method as a vanadium source; using the carbon nanometer tubes dressed by sulphuric acid and nitric acid as assembly initiation sources; mixing and stirring the V2O5 collosol and the carbon nanometer tubes for more than 1 hour; then taking the reaction for 1 to 7 days through the water heating technology at 150 to 190 DEG C; washing and filtering obtained materials by deionized water for 2 to 5 times; and baking materials at 60 to 100 DEG C for obtaining the vanadium oxide / carbon nanometer tube composite materials with the interpenetrating network structures. The composite material has wide application when being used as the lithium ion injection material in the fields such as secondary lithium ion batteries, electrochromic devices, photoelectric switches, catalysis and sensors and the like.

The invention discloses a method for quickly preparing monoclinic phase VO2. In the method, metastable phase reactant containing vanadium or VOOH reactant reacts for 1 minute to 12 hours at the temperature of 200-500 DEG C in the atmosphere of inert gases or inert gases doped with oxygen, and the monoclinic phase VO2 is obtained after cooling. The method can quickly convert the metastable phase reactant containing vanadium or VOOH into the monoclinic phase VO2 under the protection of normal-pressure inert atmosphere. The method has simple technology, low cost, high yield and favorable purity and can quickly prepare the intelligent energy-saving monoclinic phase VO2 powder on a large scale.

The invention relates to a high-performance vanadium-dioxide-based thermochromism composite. The high-performance vanadium-dioxide-based thermochromism composite comprises vanadium dioxide serving as an inorganic system thermochromic material and a dentate tronsformting body serving as an organic system thermochromic material, and the dentate tronsformting body comprises convertible metal ions, low absorbance ligands capable of forming low absorbance complexes with the convertible metal ions and high absorbance ligands capable of forming high absorbance complexes with the convertible metal ions. The high-performance vanadium-dioxide-based thermochromism composite has the advantages that the thermochromism wave band covers the whole solar radiation spectrum including visible light, and an extremely high total solar radiation adjustment rate is achieved compared with a traditional vanadium dioxide thermochromism material.