Method for preparing monoclinic phase vanadium dioxide and doped nano powder thereof

A kind of vanadium dioxide nanometer, monoclinic phase technology, applied in vanadium oxide and other directions, can solve the problems of industrial operation danger of combustion method, product purity is not particularly high, environment is not friendly, etc., to achieve superior intelligent infrared controllability, mature production equipment Simple, easy-to-industrial results

Inactive Publication Date: 2010-10-20
UNIV OF SCI & TECH OF CHINA
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  • Abstract
  • Description
  • Claims
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Problems solved by technology

[0003] So far, there are three main methods for preparing vanadium dioxide powder with intelligent infrared control properties: one is vapor deposition of VO2 powder under the protection of hydrogen or inert atmosphere. 2 (M) or high-temperature decomposition of suitable precursors, but this method requires harsh conditions and complex equipment. It not only requires expensive equipment and material costs, but it is also difficult to control the valence state of vanadium in it, and it is difficult to obtain a large amount of VO 2 (M) pure phase powder or film
Another method is by using V at high temperature 2 o 5 and V 2 o 3 Quantitative reaction to prepare, but the reaction temperature is too high, generally at 700-800 degrees Celsius, the reaction measurement is difficult to control, and the product is very impure
Another method is to dissolve certain soluble compounds containing V in ethanol, and...

Method used

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  • Method for preparing monoclinic phase vanadium dioxide and doped nano powder thereof
  • Method for preparing monoclinic phase vanadium dioxide and doped nano powder thereof
  • Method for preparing monoclinic phase vanadium dioxide and doped nano powder thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Embodiment 1 uses V0 2 (B) as a precursor

[0040] Add 5mmol V to a polytetrafluoroethylene reactor with a volume of 35ml 2 o 5 and 8mmolH 2 C 2 o 4 , then add 30ml of distilled water, stir for 30 minutes, put it into a metal kettle shell and seal it, then keep it at 200°C for 48 hours, after cooling down naturally, centrifuge the product, wash it with distilled water and industrial ethanol for 3 times, and then put the sample in a vacuum drying oven Bake at 60°C for 8 hours, then bake at 120°C for 4 hours to obtain dry VO 2 (B), then 1 g of dry VO 2 (B) Vacuum sealed into a glass tube with an inner diameter of 8mm, and annealed at 500°C for 20h to obtain pure VO 2 (M).

[0041] Its XRD and DSC charts are attached figure 2 and 3 , it can be seen from the figure that the obtained XRD peak intensity is particularly high and is in good agreement with the standard card spectrum, and the DSC peak area is large, indicating that the product has good crystallinity an...

Embodiment 2

[0042] Example 2 uses VO 2(A) as a precursor

[0043] Add 3mmol VO(acac) in a polytetrafluoroethylene reactor with a volume of 55ml 2 and 50ml of distilled water, after stirring for 30min, put it into a metal kettle shell, and then keep it at 220°C for 24h. Bake for 8 hours, and then bake for 4 hours at 120°C to obtain dry VO 2 (A), then 200mg dry VO 2 (B) Vacuum sealed into a glass tube with an inner diameter of 8mm, and annealed at 500°C for 20h to obtain pure VO 2 (M).

[0044] Its XRD and DSC charts are attached Figure 4 and 5 , it can be seen from the figure that the XRD of the obtained product is in good agreement with the standard spectrum, indicating that the product is pure VO 2 (M). attached Image 6 It is the SEM picture of the morphology of the final product. It can be seen that the obtained product is a particle powder of several hundred nanometers.

Embodiment 3

[0045] Example 3 uses Mo-doped VO 2 (B) as a precursor

[0046] Add 2.25mmol V in a polytetrafluoroethylene reactor with a volume of 35ml 2 o 5 , 0.25mmolNa 2 MoO 4 and 4 mmol H 2 C 2 o 4 2H 2 O, then add 30ml of distilled water, stir for 30 minutes, put it into a metal kettle shell and seal it, then keep it at 200°C for 48 hours, after cooling down naturally, centrifuge the product, wash it with distilled water and industrial ethanol for 3 times, and then dry the sample in vacuum Baked at 60°C for 8 hours in an oven, and then baked at 120°C for 4 hours to obtain dry Mo-doped VO 2 (B), then 200 mg of dry Mo-doped VO 2 (B) Vacuum sealed into a glass tube with an inner diameter of 8mm, and annealed at 500°C for 20h to obtain Mo-doped VO 2 (M).

[0047] Its XRD and DSC charts are attached Figure 7 and 8 , it can be seen from the figure that the XRD and VO of the final product 2 (M) The standard spectrum is very consistent, and the DSC peak is also reduced to about ...

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Abstract

The invention provides a method for preparing nano powder of monoclinic phase vanadium dioxide by using a hydrothermal-high temperature solid phase synthesis method. The method comprises the following steps of: a) reacting a vanadium source with a reducing agent to obtain vanadium dioxide (VO2)(B), VO2(A) or VO2 (paramontroseite) by using a hydrothermal method; b) washing the VO2(B), the VO2(A) or the VO2 (paramontroseite) and then thoroughly drying the VO2(B), the VO2(A) or the VO2 (paramontroseite) to form powder; c) vacuum-packaging the powder of the VO2(B), the VO2(A) or the VO2 (paramontroseite) in an airtight and high-temperature resistant container; and d) annealing the container at the temperature of between 350 and 1,200 DEG C for over 3 hours to obtain the nano powder of the monoclinic phase vanadium dioxide. The method has the characteristics of simple production technology, low production cost, environmental friendliness, higher product yield, higher product purity and easy industrial mass production.

Description

technical field [0001] The invention relates to the technical field of nanomaterial synthesis, in particular to the preparation of VO by hydrothermal-high temperature solid-phase synthesis 2 (M) The method of nanopowder. Background technique [0002] Vanadium (V) oxide compounds are recognized as an important class of thermochromic materials. As the ambient temperature changes, the crystal structure, electric domain structure, and magnetic structure of the vanadium oxide compound will change greatly, resulting in a huge change in its optical properties. Among various vanadyl compounds, the monoclinic phase VO 2 (M) has been receiving extensive attention from both scientific and industrial circles due to the appropriate phase transition temperature, i.e., at 68 °C, the monoclinic phase VO 2 (M) (low temperature insulating phase) will transform into tetragonal rutile phase VO 2 (R) (high temperature metal phase), while the conductivity will occur 10 5 With an order of mag...

Claims

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Application Information

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IPC IPC(8): C01G31/02
Inventor 谢毅白亮飞宋磊
Owner UNIV OF SCI & TECH OF CHINA
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