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Preparation method of M-phase vanadium dioxide

A technology of vanadium dioxide and vanadium salt, applied in vanadium oxide, nanotechnology for materials and surface science, nanotechnology, etc. Treatment and other problems to achieve the effect of reducing vanadium-containing wastewater, reducing production costs and uniform distribution

Inactive Publication Date: 2017-05-31
SOUTHWEST UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

This patent is a hydrothermal reaction under acidic conditions. From the XRD results, it can be judged that the particle size of the obtained product is relatively large, which does not meet the small particle size requirements of nano-products. Moreover, the precursor is very easy to dissolve under acidic conditions. It is difficult to obtain the target product
In addition, in the process of centrifuging the reaction product to obtain precipitation in step 1, a large amount of vanadium-containing waste liquid will be produced, which is highly toxic and difficult to handle

Method used

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  • Preparation method of M-phase vanadium dioxide
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  • Preparation method of M-phase vanadium dioxide

Examples

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Effect test

Embodiment 1

[0030] Weigh 1 g of ammonium metavanadate, add 30 mL of deionized water, heat to 100 ° C to dissolve, and then quickly add a 5% hydrazine solution (the molar ratio of hydrazine to ammonium metavanadate is 1:4), Incubate at 100°C for 10 minutes, heat at 100°C to evaporate the solvent; then add deionized water to form a suspension, and ultrasonically disperse for 10 minutes to obtain a precursor dispersion (in terms of the mass of vanadium dioxide, the mass of the precursor dispersion concentration of 5%). The dispersion was transferred to a 20 mL reactor, hydrothermally treated at 260°C for 24 hours, after the hydrothermal crystallization was completed, the product was obtained by centrifugation, washed three times with water and ethanol, and then washed once with acetone. After drying at ℃, 0.7g M-phase VO can be obtained 2 Nano powder. The obtained powder particle size is as figure 1 As shown, most of the particles have a particle size of about 20 nm, and the largest does ...

Embodiment 2

[0032] Weigh 0.1g of ammonium metavanadate, add 5mL of deionized water, heat to 100°C to dissolve, and then quickly add a 5% diluted hydrazine solution (the molar ratio of hydrazine to ammonium metavanadate is 1:1) Incubate at 100 ° C until the solvent is completely evaporated; then add deionized water to form a suspension, and ultrasonically disperse for 10 minutes to obtain a precursor dispersion (in terms of the mass of vanadium dioxide, the mass concentration of the precursor dispersion is 0.5%). The dispersion was transferred to a 20 mL reaction kettle, and hydrothermally treated at 240 ° C for 48 hours. After the hydrothermal crystallization was completed, the product was obtained by vacuum filtration, washed three times with water and ethanol, and then once with acetone. After drying at 40℃, 0.07gM phase VO can be obtained 2 Nano powder. The powder can be directly added into 10 mL of deionized water to form a vanadium dioxide colloid, and the colloid has good stabilit...

Embodiment 3

[0034] Weigh 2g of ammonium metavanadate, add 30mL of deionized water, heat to 80°C to dissolve, then quickly add L-ascorbic acid (the molar ratio of L-ascorbic acid and ammonium metavanadate is 1:2), keep at 80°C for 10 minutes , heated at 100 ° C to evaporate the solvent; then added deionized water to form a suspension, ultrasonically dispersed for 10 minutes to obtain a precursor dispersion (in terms of the mass of vanadium dioxide, the mass concentration of the precursor dispersion is 5%) . The dispersion was transferred to a 20 mL reaction kettle, and hydrothermally treated at 180 ° C for 240 hours. After the hydrothermal crystallization was completed, the product was obtained by centrifugal separation, washed three times with water and ethanol, and then once with acetone. ℃ drying, you can get 1.4gM phase VO 2 Nano powder.

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Abstract

The invention relates to a preparation method of M-phase vanadium dioxide. The preparation method comprises the following steps of preparation of a precursor and hydrothermal crystallizing, and is characterized in that the prepared precursor is directly subject to hydrothermal crystallizing without separation. A preparation method of the precursor comprises one of the following steps of (A) dissolving soluble vanadium salt into water, adding a reductant, heating to evaporate out solvent after reaction is finished, adding water, and dispersing by ultrasonic waves, so as to obtain precursor dispersing liquid; (B) adding the soluble vanadium salt and a complexing agent into water, and dissolving to form a complexing precursor. The preparation method has the advantages that no gas is produced in the hydrothermal crystallizing process, so that the solid content of the precursor after hydrothermal treatment is high; the preparation method is suitable for industrial scaled production, the production cost is directly reduced, the production efficiency is improved, and the requirements of actual application are met.

Description

technical field [0001] The invention belongs to the technical field of functional materials, and relates to a preparation method of M-phase vanadium dioxide. Background technique [0002] M-phase vanadium dioxide has metal-insulator transition characteristics, when the temperature is raised to the phase transition temperature, VO 2 The transformation from the low temperature monoclinic phase to the high temperature tetragonal phase is reversible. Before and after the phase transition, in the infrared region, its optical properties have changed greatly, that is, from infrared transmission to infrared blocking. Therefore, as the ambient temperature changes, the vanadium dioxide-based film can realize the regulation of infrared rays in sunlight, making it useful in smart windows. [0003] The phase purity, crystallinity, particle size, and particle dispersibility of the powder will directly affect the VO 2 The phase transition control performance. And as a practical applica...

Claims

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Application Information

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IPC IPC(8): C01G31/02B82Y30/00
CPCC01G31/02C01P2002/72C01P2002/88C01P2004/04C01P2004/64
Inventor 邹建
Owner SOUTHWEST UNIVERSITY
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