Method of preparing catalyst for manufacturing carbon nanotubes

Abstract

A novel method of forming catalyst particles, on which carbon nanotubes grow based, on a substrate with increased uniformity, and a method of synthesizing carbon nanotubes having improved uniformity are provided. A catalytic metal precursor solution is applied to a substrate. The applied catalytic metal precursor solution is freeze-dried, and then reduced to catalytic metal. The method of forming catalyst particles can minimize agglomeration and / or recrystallization of catalyst particles when forming the catalyst particles by freeze-drying the catalyst metal precursor solution. The catalyst particles formed by the method has a very uniform particle size and are very uniformly distributed on the substrate.

Description

CLAIM OF PRIORITY [0001] This application claims the priority of Korean Patent Application No. 10-2004-0046552, filed on Jun. 22, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a method of preparing a catalyst for manufacturing carbon nanotubes and a method of manufacturing carbon nanotubes using the same. [0004] 2. Description of the Related Art [0005] A carbon nanotube has a cylindrical structure having a diameter of several nano-meter and a very large aspect ratio of about 10 to 1,000. In the carbon nanotube, carbon atoms are generally arranged in a hexagonal honeycomb pattern. One carbon atom bonds to three adjacent carbon atoms. The carbon nanotube may be a conductor or a semiconductor according to its structure. As a conductor, the carbon nanotube has high electroconductivity. Also, the carbon nanot...

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Benefits of technology

[0013] It is a further object of the present invention to provide a novel method of forming catalyst particles with increased uniformity, on which carbon nanotubes grow based, on a substrate.

[0017] The method of forming catalyst particles can minimize the agglomeration and / or recrystallization of the catalytic metal particles when forming the catalytic metal particles by freeze-drying the catalytic metal precursor solution. Therefore, the catalytic metal particles formed by the method of the present invention have particle sizes with very high uniformity and are very uniformly distributed on the substrate.

Problems solved by technology

The arc discharge and the laser deposition have relatively low yields of carbon nanotubes.

When using the arc discharge and the laser deposition, It is difficult to control the diameter and the length of the carbon nanotube.

Further, in the arc discharge and the laser deposition, clusters of amorphous carbon besides the carbon nanotubes are produced in a large amount, and thus a complicated purifying process must be performed.

However, in this case, recrystallization and agglomeration of the catalytic metals occur during the drying and heat-treatment processes so that uniformity of the catalyst particles formed on the substrate is deteriorated.

Due to the deterioration in the uniformity of the catalyst particles formed on the substrate, the uniformity of the diameter and production density of the carbon nanotubes grown on the basis of the catalytic particles are both deteriorated.

The uniformity of the catalyst particles formed by the conventional methods is not sufficient.

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