JP2004168611A - Method of manufacturing orientation multilayer nanotube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel method of an orientation multilayer nanotube by which a multilayer boron nitride nanotube or a multilayer nanotube composed of boron, carbon and nitrogen atoms which is useful as a semiconductor material, a flat panel display material, an emitter material, a heat resistant filler, a high strength material, a catalyst or the like and has the high orientation property is simply manufactured. <P>SOLUTION: The multilayer boron nitride nanotube having the orientation property is produced by reacting boron oxide, copper oxide, molybdenum oxide (4) and nitrogen (5) with a multilayer carbon nanotube (2) at a high temperature of 1,500-2,500°K. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The invention of this application relates to a method for producing an oriented multi-walled nanotube. More specifically, the present invention relates to a method for producing an oriented multi-walled nanotube useful as a semiconductor material, a flat panel display material, an emitter material, a heat-resistant filling material, a high-strength material, a catalyst, and the like.
[0002]
[Prior art]
A tubular carbon material (carbon nanotube) having a nanometer size in which carbon atoms are arranged in a cylindrical shape is conventionally known [Reference 1: Nature, Vol. 354, p. 56, 1991]. It is also known that carbon nanotubes produced by an arc discharge method or a laser heating method do not show orientation [Reference 2: Book by MS Dresselhaus et al., Science of. Fullrens and Carbon Nanotubes, Academic, San Diego, 1996. Literature 3: PJF Harris, Carbon Nanotubes and Related Structures New Materials for the Twenty-first Century, Cambridge, Canada, United Kingdom. On the other hand, it has become possible to synthesize oriented multi-walled carbon nanotubes by using the chemical vapor deposition method [Reference 4: Science, vol. 274, p. 1701, 1996. Reference 5: Nature, 388, 52, 1997. Reference 6: Science 283, 512, 1999. Reference 7: Journal of Nanoscience and Nanotechnologies (J. Nanosci. Nanotechnol.) 1, 43, 2001].
[0003]
In recent years, it has been known that, compared to carbon nanotubes, multi-walled boron nitride nanotubes having a wider band gap and different conductivity and multi-walled nanotubes composed of boron-carbon-nitrogen atoms can be synthesized [Reference 8: Science]. 266, 1683, 1994. Reference 9: Science, 269, 966, 1995. Reference 10: Chemical Materials (Chem. Mater.) 12, p. 1808, 2000. Reference 11: Chemical Physics Letters (Chem. Phys. Lett.) 362, 185, 2002. Reference 12: Chemical Physics Letters (Chem. Phys. Lett.), 360, page 1, 2002. Reference 13: Chemical Physics Letters (Chem. Phys. Lett.) 359, 220, 2002. ].
[0004]
However, boron nitride nanotubes or nanotubes consisting of boron / carbon / nitrogen atoms are expected to have unprecedented properties as semiconductor materials, flat panel display materials, emitter materials, heat-resistant filling materials, high-strength materials, catalysts, etc. However, the nanotubes manufactured by the conventional method cannot be used as a functional material having the above-mentioned characteristics because the organization of the nanotubes is disordered.
[0005]
[Problems to be solved by the invention]
Therefore, the invention of this application has been made in view of the above circumstances, and has a high orientation that is useful as a semiconductor material, a flat panel display material, an emitter material, a heat resistant filling material, a high strength material, a catalyst, and the like. It is an object of the present invention to provide a new method for producing a multi-walled oriented carbon nanotube capable of easily producing a multi-walled boron nitride nanotube having a property or a multi-walled nanotube composed of boron / carbon / nitrogen atoms.
[0006]
[Means for Solving the Problems]
The invention of this application solves the above-mentioned problems. First, at a high temperature of 1500 K to 2500 K, boron oxide, copper oxide, molybdenum oxide, and nitrogen are reacted with multi-walled carbon nanotubes, The present invention provides a method for producing an oriented multi-walled nanotube characterized by producing a multi-walled boron nitride nanotube having the following.
[0007]
The invention of this application is directed to a method for producing the above-mentioned oriented multi-walled nanotubes, in which boron oxide, copper oxide, and molybdenum oxide are multi-layered by heating at 1500 K to 2500 K in a flowing nitrogen gas atmosphere. Thirdly, a method for producing an oriented multi-layered nanotube characterized by reacting with carbon nanotubes to produce multi-layered boron nitride nanotubes having an orientation, and thirdly, heating to 1500 K to 2500 K in a flowing nitrogen gas atmosphere. By reacting boron oxide, copper oxide, and molybdenum oxide with the multi-walled carbon nanotubes, after the reaction, the product generated by the reaction is cooled to room temperature in a flowing nitrogen gas atmosphere, and the multi-layer nitriding with orientation is performed. Oriented multi-layer nanotubes for producing boron nanotubes To provide a method of manufacturing a tube.
[0008]
Further, the invention of this application, the fourth, the high temperature of 1500K～2500K, boron oxide, copper oxide, and, nitrogen, reacted oriented multilayer nanotubes consisting of CN _X is a compound of carbon and nitrogen To provide an oriented multi-walled nanotube comprising boron, carbon, and nitrogen.
[0009]
The invention of this application is directed to a method for producing the above-mentioned oriented multi-walled nanotubes by heating boron oxide and molybdenum oxide in a flowing nitrogen gas atmosphere to 1500 K to 2500 K to convert CN oxide, a compound of carbon and nitrogen, into CN _X A method for producing oriented multi-walled nanotubes comprising reacting with oriented multi-walled nanotubes consisting of boron, carbon and nitrogen, and sixthly, in a flowing nitrogen gas atmosphere. And heating the mixture to 1500 K to 2500 K, thereby reacting boron oxide and molybdenum oxide with an oriented multi-walled nanotube composed of CN _X which is a compound of carbon and nitrogen. Cool to room temperature in a gas atmosphere and remove from boron, carbon and nitrogen. To provide a production method of the oriented multilayer nanotubes and generates orientation multi-walled nanotubes.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention of this application has the features as described above, and embodiments thereof will be described below.
[0011]
In the method for producing oriented multi-walled nanotubes according to the invention of the present application, under high temperature, boron oxide, copper oxide, molybdenum oxide, and nitrogen are reacted with carbon nanotubes to produce multi-walled boron nitride nanotubes having orientation. Generate At this time, the temperature of the atmosphere is preferably 1500 K to 2500 K, and it is preferable that carbon nanotubes, boron oxide, copper oxide, molybdenum oxide, and nitrogen are reacted in a flowing nitrogen gas atmosphere. Further, it is preferable to cool the product obtained after the reaction to room temperature in a flowing nitrogen gas atmosphere.
[0012]
In the production method of the invention a is oriented multi-walled nanotubes in this application, at high temperatures, boron oxide, copper oxide, and, nitrogen, be reacted nanotubes consisting of CN _X is a compound of carbon and nitrogen Thereby, an oriented multi-walled nanotube composed of boron, carbon, and nitrogen is generated. At this time, it is preferable that the temperature of the atmosphere be 1500 K to 2500 K, and that the carbon nanotubes, boron oxide, copper oxide, and nitrogen be reacted in a flowing nitrogen gas atmosphere. Further, it is preferable to cool the product obtained after the reaction to room temperature in a flowing nitrogen gas atmosphere.
[0013]
In order to produce oriented multi-walled boron nitride nanotubes, it is necessary to prepare multi-walled carbon nanotubes as a starting material. The multi-walled carbon nanotube is obtained by using a polished wafer made of stainless steel as a substrate, reacting nitrogen gas, hydrogen gas, and methane gas at a substrate temperature of about 773 K by a CVD method and depositing the reaction gas on the substrate.
[0014]
Further, in order to produce an oriented multilayer nanotubes consisting of boron, carbon and nitrogen atom, as a starting material, it is necessary to synthesize the orientation of multilayer nanotubes consisting of CN _X is a compound of carbon and nitrogen. Oriented multi-walled nanotubes composed of CN _X can be obtained by firing a mixture of ferrocene and melamine at a high temperature of 1273K to 1323K in an argon atmosphere.
[0015]
The starting material generated as described above acts as a reactive template material.
[0016]
FIG. 1 is a schematic diagram showing a configuration for carrying out the method for producing an oriented multi-walled nanotube according to the invention of the present application.
A starting material (2) is dispersed on a substrate (1) made of porous graphite, and this substrate (1) is placed on a cylindrical crucible (3) made of graphite. On the other hand, the lower part of the crucible (3) is filled with a reactant (4). Here, the reactant (4) is a substance that reacts with the starting material (2). That is, when the starting material (2) is a multi-walled carbon nanotube, the lower portion of the crucible (3) is filled with boron oxide, copper oxide, and molybdenum oxide as the reactant (4). ) Is an oriented multi-walled nanotube composed of CN _X, the lower portion of the crucible (3) is filled with boron oxide and copper oxide as a reactant (4).
[0017]
While flowing the nitrogen gas (5) into the crucible (3), the crucible (3) is heated at a high temperature of 1500K to 2500K in a high-frequency induction heating furnace. Further, annealing is performed for several tens of minutes while flowing nitrogen gas at a flow rate of several L / min. After the reaction, the inside of the high-frequency induction heating furnace is cooled for several hours while the nitrogen gas (5) flows into the crucible (3) until the temperature of the furnace becomes room temperature. Thereby, a multi-layer boron nitride nanotube having a high orientation or a multi-layer nanotube composed of boron, carbon, and nitrogen can be obtained.
[0018]
The above is an example of the mode in the invention of this application, and it is needless to say that the invention of this application is not limited to these, and that various details can be taken in detail.
[0019]
The invention of this application has the above-mentioned features, and will be described in more detail with reference to examples below.
[0020]
【Example】
Example 1
A polished stainless steel wafer was used as a substrate, and nitrogen gas (purity 99.999%), hydrogen gas (purity 99.999%), and methane gas (purity 99.9%) were used as a carrier gas and a carbon source. The gas flow rate was set to 80 (hydrogen) sccm and 20 (methane) sccm, and multi-walled carbon nanotubes were produced by a plasma CVD method. During the growth of the carbon nanotubes, the temperature of the substrate was maintained at 773K.
[0021]
The multi-walled carbon nanotubes as the reactive template substance thus produced were dispersed on a substrate made of porous graphite. This graphite substrate was placed on the upper part of a graphite crucible made of graphite. The lower portion of the crucible was filled with a powder of boron oxide, copper oxide, and molybdenum oxide so as to form a continuous layer. Then, it was heated to 1973K in a high-frequency induction heating furnace while flowing nitrogen gas into the crucible. Furthermore, annealing was performed for 30 minutes while flowing nitrogen gas at a flow rate of 3 L / min. Thereafter, the mixture was cooled to room temperature in 2 hours while continuously flowing nitrogen gas into the crucible.
[0022]
FIG. 2 shows the results of observing the produced multi-layer boron nitride nanotubes with a high-resolution transmission electron microscope. From FIG. 2, it was confirmed that the tissues were arranged linearly with high orientation. Its diameter was 8-15 nm.
[0023]
FIG. 3 shows the measurement results of the electron energy loss spectrum. From FIG. 3, as a result of the electron energy loss spectrum analysis, it was confirmed that the ratio of boron to nitrogen was 1: 1.
Example 2
A mixture of ferrocene and melamine and calcined at 1293K in an argon atmosphere, to produce an oriented multilayer nanotubes consisting of CN _X. The oriented multi-walled nanotube made of CN _X was dispersed on a substrate made of porous graphite in the same manner as in Example 1. This graphite substrate was placed on the upper part of a graphite crucible made of graphite. The lower portion of the crucible was filled with a powder of boron oxide, copper oxide, and molybdenum oxide so as to form a continuous layer. Then, the mixture was heated to 2113K in a high-frequency induction heating furnace while flowing nitrogen gas into the crucible. Furthermore, annealing was performed for 30 minutes while flowing nitrogen gas at a flow rate of 3 L / min. Thereafter, the mixture was cooled to room temperature in 2 hours while continuously flowing nitrogen gas into the crucible.
[0024]
FIG. 4 shows the result of observing the formed multi-walled nanotube composed of boron, carbon, and nitrogen with a high-resolution transmission electron microscope. From FIG. 4, it was confirmed that the tissues were arranged linearly with high orientation.
[0025]
FIG. 3 shows the measurement results of the electron energy loss spectrum. From FIG. 3, the result of electron energy loss spectrum analysis confirmed that the ratio of boron, carbon, and nitrogen was 0.46: 1.00: 0.22.
[0026]
【The invention's effect】
According to the invention of this application, as described in detail above, multi-oriented boron nitride nanotubes or boron-based materials having high orientation useful as semiconductor materials, flat panel display materials, emitter materials, heat-resistant filling materials, high-strength materials, catalysts, etc. There is provided a novel method for producing a multi-walled oriented nanotube which enables simple production of a multi-walled nanotube composed of carbon and nitrogen atoms.
[0027]
According to the method for producing oriented multi-walled nanotubes of the invention of this application, multi-walled boron nitride nanotubes having extremely high orientation or multi-walled nanotubes composed of boron / carbon / nitrogen atoms can be produced simply and inexpensively. These oriented multi-walled nanotubes have unprecedented properties as semiconductor materials, flat panel display materials, emitter materials, heat-resistant filling materials, high-strength materials, catalysts, etc., and are therefore used as advanced functional materials in advanced fields. There is expected.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration for implementing a method for producing an oriented multi-walled nanotube according to the invention of the present application.
FIG. 2 is a high-resolution transmission electron microscope image of a multi-layer boron nitride nanotube produced in an example of the present invention.
FIG. 3 is a graph showing an electron energy loss spectrum of a multi-layer boron nitride nanotube produced in an example of the present invention.
FIG. 4 is a high-resolution transmission electron microscope image of a multi-walled nanotube composed of boron, carbon, and nitrogen produced in an example of the present invention.
FIG. 5 is a graph showing an electron energy loss spectrum of a multi-walled nanotube composed of boron, carbon, and nitrogen produced in an example of the present invention.
[Explanation of symbols]
1 substrate 2 starting material 3 crucible 4 reactant 5 nitrogen gas

Claims (6)

At a high temperature of 1500 K to 2500 K, boron oxide, copper oxide, molybdenum oxide, and nitrogen are reacted with the multi-walled carbon nanotube to produce a multi-layered boron nitride nanotube having an orientation. Production method. In a flowing nitrogen gas atmosphere, by heating to 1500K to 2500K, boron oxide, copper oxide, and molybdenum oxide are reacted with the multi-walled carbon nanotubes to produce multi-walled boron nitride nanotubes having orientation. The method for producing an oriented multi-walled nanotube according to claim 1. By heating to 1500K to 2500K in a flowing nitrogen gas atmosphere, boron oxide, copper oxide, and molybdenum oxide react with the multi-walled carbon nanotube, and after the reaction, a nitrogen gas atmosphere in which a product generated by the reaction flows. The method for producing an oriented multi-walled nanotube according to claim 2, wherein the multi-layered boron nitride nanotube having an orientation is produced by cooling to room temperature in the inside. In high temperature 1500K～2500K, boron oxide, copper oxide, and, nitrogen, reacted oriented multilayer nanotubes consisting of CN _X is a compound of carbon and nitrogen, boron, carbon, oriented multilayer nanotubes consisting of nitrogen A method for producing oriented multi-walled nanotubes, characterized in that: In a nitrogen gas atmosphere to flow, by heating the 1500K～2500K, reacted oriented multilayer nanotubes comprising boron oxide and molybdenum oxide from CN _X is a compound of carbon and nitrogen, comprising boron, carbon, nitrogen The method for producing an oriented multi-walled nanotube according to claim 4, wherein the oriented multi-walled nanotube is produced. In a nitrogen gas atmosphere to flow, by heating the 1500K～2500K, reacted oriented multilayer nanotubes comprising boron oxide and molybdenum oxide from CN _X is a compound of carbon and nitrogen, after the reaction, it was generated by the reaction The method for producing an oriented multi-walled nanotube according to claim 5, wherein the product is cooled to room temperature in a flowing nitrogen gas atmosphere to produce an oriented multi-walled nanotube composed of boron, carbon, and nitrogen.

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