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Process for preparing vanadium dioxide nano powder

A vanadium dioxide nanometer and powder material technology, applied in vanadium oxide and other directions, can solve the problems of adverse effects on the environment and operator's health, difficult process control, high heating furnace power, etc., and achieves less equipment investment and obvious phase change. Features, the effect of small power requirements

Inactive Publication Date: 2005-11-09
SICHUAN UNIV
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  • Application Information

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Problems solved by technology

The problem that said method exists is: 1, contain ammonium in the raw material, therefore must control the content of ammonium to guarantee to obtain accurate VO 2 structure, which brings difficulties to process control; 2. The temperature rise rate of the precursor pyrolysis is at least 100°C / min, so the power of the heating furnace is relatively large, which increases the cost of the equipment; 3. The particle size of the prepared vanadium dioxide particles is Micron-scale (dimensions smaller than a micron)
The above-mentioned method not only has more complicated process steps, but also has adverse effects on the environment and the health of operators due to the use of hydrochloric acid and ammonia-containing substances as raw materials.

Method used

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  • Process for preparing vanadium dioxide nano powder
  • Process for preparing vanadium dioxide nano powder
  • Process for preparing vanadium dioxide nano powder

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Experimental program
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Effect test

Embodiment 2

[0059] Embodiment 2: Preparation of Mo-doped vanadium dioxide nanopowder material

[0060] The first group: choose industrial grade V 2 o 5 , V 2 o 5 with MoO 3 The formula is calculated by weight percentage: V 2 o 5 99%, MoO 3 1%; V 2 o 5 The weight ratio with oxalic acid is 1:1.

[0061] (1) Preparation of precursor

[0062] The above ratio of V 2 o 5 with MoO 3 Mix well and place in a container. , heated to 800°C under normal pressure to become a molten state, then pour the melt into a reaction vessel equipped with water and stir (the amount of water added is such that V 2 o 5 with MoO 3 melt), then add metered oxalic acid to the above solution and continue to stir until the reduction reaction is completed (about 3 hours). After the reduction reaction is completed, a blue liquid without precipitation is obtained. The solid precursor of vanadyl oxalate doped with Mo ions was obtained by evaporating to dryness at ℃.

[0063] (2) Thermal decomposition of pr...

Embodiment 3

[0087] Embodiment 3: Preparation of W-doped vanadium dioxide nanopowder material

[0088] The first group: choose industrial grade V 2 o 5 , V 2 o 5 with N 5 h 37 W 6 o 24 The formula is calculated by weight percentage: V 2 o 5 99%, N 5 h 37 W 6 o 24 1%; V 2 o 5 The weight ratio with oxalic acid is 1:1

[0089] (1) Preparation of precursor

[0090] The ratio of V 2 o 5 , oxalic acid, N 5 h 37 W 6 o 24 and V 2 o 5 Put polyethylene glycol with 2% of the total weight of oxalic acid into a reaction vessel, add water and stir at normal pressure and 40°C for about 3 hours to complete the reduction reaction. After the reaction was completed, a blue liquid without precipitation was obtained, and the obtained solution was evaporated to dryness at 80° C. to obtain a solid vanadyl oxalate precursor doped with W ions.

[0091] (2) Thermal decomposition of precursors

[0092] Put the obtained vanadyl oxalate precursor into a tubular heating furnace after pulveri...

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Abstract

A process for preparing VO2 nanoparticles includes such steps as proportionally adding V2O5 and oxalic acid to reactor, adding water, stirring at 40-70 deg.C while reaction, evaporating to obtain solid vanadium oxalate, vacuum heating to 350-500 deg.C, holding the temp for 20-40 min for thermodecomposing, and cooling. It is possible to add MoO3 or N5H37W6O24 for preparing the doped product.

Description

technical field [0001] The invention belongs to a method for preparing a vanadium dioxide powder material, in particular to a method for preparing a vanadium dioxide nanometer powder material. Background technique [0002] VO 2 It is a typical phase change compound. As the phase change occurs, the resistivity, magnetic susceptibility, optical refractive index, transmittance and reflectance change suddenly, and the phase change process is reversible. These characteristics can make VO 2 Applications to intelligent temperature-controlled glass for buildings, photoelectric switch materials, thermistor materials, erasable optical storage materials, laser blinding weapon protection devices, photochromic materials, modulators for submicron wave radiation, etc. Therefore, for VO 2 The research on its preparation method has very important value. [0003] The Chinese patent application with the application number 95196132.2 discloses a method for ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01G31/02
Inventor 黄维刚林华范樵乔涂铭旌
Owner SICHUAN UNIV
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