Method for preparing boron nitride nanotube by magnesium reduction

A boron nitride nanotube and magnesium heating technology, applied in chemical instruments and methods, nitrogen compounds, inorganic chemistry, etc., can solve the problems of large size span of nanotubes, affecting the service life of equipment, unstable chemical properties, etc. The effect of no structure, low preparation cost and easy purification

Inactive Publication Date: 2009-01-21
BEIJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If an aqueous system such as water or hydrochloric acid is used as a growth accelerator for boron nitride nanotubes, the obtained nanotubes have a large size span, usually about ten to two hundred nanometers, and most of them are bamboo-shaped nanotubes, while water-containing or The acid gas will cause great damage to the reaction vessel and equipment at high temperature, which will affect the service life of the equipment and lead to an increase in production cost; using magnesium oxide-ferrous oxide as a catalyst for preparing boron nitride nanotubes, a certain process can be used to obtain Boron nitride nanotubes with higher purity and uniform size have the potential to be mass-produced, but this method requires expensive high-purity boron powder as a boron source, and uses ferrous oxide, which is chemically unstable, as a catalyst. Higher preparation cost

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  • Method for preparing boron nitride nanotube by magnesium reduction

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] 1) Under the protection of argon, place boron oxide, magnesium and ferrous chloride in a molar ratio of 1:1:0.1 in an agate mortar and thoroughly grind to completely mix the reactants, then pass through a 300-mesh sieve;

[0018] 2) Put the mixture sieved in step 1) into an aluminum oxide porcelain boat and place it in the constant temperature zone of a horizontal tube furnace, feed 50 sccm of argon gas, start to heat up, and when the temperature reaches 900°C, turn off the argon Gas and feed 50sccm ammonia gas to continue to heat up, when it reaches 1200°C, keep the temperature constant for 5 hours;

[0019] 3) At the end of the constant temperature, close the air inlet and exhaust port at the same time, and cool down to room temperature with the furnace. The product in the porcelain boat is a white spongy block, which is full of elasticity. After washing away impurities containing magnesium and iron with nitric acid, the product is uniform. White powder with no signif...

Embodiment 2

[0021] 1) Under the protection of argon, place boron oxide, magnesium and ferrous sulfate in a molar ratio of 1:2:0.05 in an agate mortar and thoroughly grind to completely mix the reactants, then pass through a 300-mesh sieve;

[0022] 2) Put the mixture sieved in step 1) into an aluminum oxide porcelain boat and place it in the constant temperature zone of a horizontal tube furnace, feed 100 sccm of argon gas, start to heat up, and when the temperature reaches 1100°C, turn off the argon Gas and feed 100sccm ammonia gas to continue heating up, when it reaches 1400°C, keep the temperature constant for 2 hours;

[0023] 3) At the end of the constant temperature, close the air inlet and exhaust port at the same time, and cool down to room temperature with the furnace. The product in the porcelain boat is a white spongy block, which is full of elasticity. After washing away impurities containing magnesium and iron with nitric acid, the product is uniform. White powder with no sig...

Embodiment 3

[0025] 1) Under the protection of argon, place boron oxide, magnesium and ferrous oxalate in a molar ratio of 1:3:0.01 in an agate mortar and thoroughly grind to mix the reactants completely, then pass through a 300-mesh screen;

[0026] 2) Put the mixture sieved in step 1) into an aluminum oxide porcelain boat and place it in the constant temperature zone of a horizontal tube furnace, feed 200 sccm of argon gas, start to heat up, and when the temperature reaches 1200°C, turn off the argon Gas and feed 200sccm ammonia gas to continue heating, when it reaches 1600°C, keep the temperature constant for 1 hour;

[0027] 3) At the end of the constant temperature, close the air inlet and exhaust port at the same time, and cool down to room temperature with the furnace. The product in the porcelain boat is a white spongy block, which is full of elasticity. After washing away impurities containing magnesium and iron with nitric acid, the product is uniform. White powder with no signif...

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Abstract

The invention provides a method for preparing a borazon nano pipe by the magnesium-thermic reduction, belonging to the inorganic nano material field. In the prior method for preparing the borazon nano pipe, the problems of low yield and high cost exist. The method of the invention comprises the following steps that : (1) under argon shield, according to the mol ratio of 1:1-3:0.01-0.1, borazon, magnesium and ferrous salt are ground, mixed and screened; (2) under argon shield, the screened mixture is heated, and at a temperature of between 900 and 1,200 DEG C, argon gas is closed and the ammonia gas is filled, and when the temperature reaches between 1,200 and 1,600 DEG C, the temperature is maintained for 1 to 5h; (3) after the temperature decreases to the room temperature, the mixture is immersed in nitric acid, the product obtained has impurities removed, and the borazon nano pipe is obtained. The method of the invention has the advantages of simple process, easy control and amplification of reaction, low cost, high yield and uniform size and high purity of the prepared borazon nano pipe.

Description

technical field [0001] The invention belongs to the field of inorganic nanometer materials, and in particular relates to a method for preparing boron nitride nanotubes by a magnesia thermal reduction method. Background technique [0002] Hexagonal boron nitride and graphite are isoelectronics with very similar layered structures. Like carbon nanotubes, boron nitride can also form corresponding tubular nanostructures. In addition to the high modulus and high toughness comparable to carbon nanotubes, boron nitride nanotubes also have good chemical and thermal stability. In addition, boron nitride nanotubes have completely different electrical properties from carbon nanotubes, and behave as semiconductors with wide bandgap (~5.5eV), and their electrical properties are independent of tube diameter, helicity and tube wall number. The unique characteristics of boron nitride nanotubes make them have very attractive application prospects in nano-semiconductor devices, nano-composi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B21/064
Inventor 李永利张久兴
Owner BEIJING UNIV OF TECH
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