# US 8,541,054 B2 · Methods for preparation of one-dimensional carbon nanostructures

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- Number: US 8,541,054 B2
- Document ID: US8541054B2
- Status: Granted
- Kind: B2
- Application number: 10/658,711
- Filed: 2003-09-08
- Published: 2005-03-10
- Granted: 2013-09-24
- Earliest claimed: 2003-09-08
- Assignees: Honda Motor Co., Ltd.
- Applicants: Avetik Harutyunyan
- Inventors: Avetik Harutyunyan
- Web page: https://patentgrep.com/patent/US8541054B2

## CPC

- C01B 32/162: characterised by catalysts
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- B82Y 40/00: Manufacture or treatment of nanostructures
- C23C 14/042: {using masks}
- C23C 14/12: Organic material
- D01F 9/12: Carbon filaments; Apparatus specially adapted for the manufacture thereof
- D01F 9/1271: {Alkanes or cycloalkanes}
- D01F 9/1272: {Methane}
- C01B 2202/02: Single-walled nanotubes
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS

## Abstract

A method for synthesizing carbon nanostructures is provided. A metalorganic layer is deposited on a substrate that has a deposition mask. The mask is removed, which also removes the portion of the metalorganic precursor deposited on the mask. The remaining portions of the metal organic layer are oxidized to produce a metal growth catalyst on the substrate that can be used for synthesis of carbon nanostructures.

## Claims

### Claim 1

A method for synthesizing single wall carbon nanotubes, the method comprising the steps of:
providing a substrate having a deposition mask;
depositing a bimetallic or trimetallic metalorganic layer on the substrate, wherein at least a portion of the bimetallic or trimetallic metalorganic layer is deposited on an unmasked portion of the substrate, and wherein the bimetallic or trimetallic metalorganic layer comprises an organic portion and an inorganic portion, and wherein the bimetallic or trimetallic metalorganic layer has a thickness of 1 micron;
removing the deposition mask from the substrate;
exposing said portion of the bimetallic or trimetallic metalorganic layer to air;
pyrolyzing the organic portion of said portion of the bimetallic or trimetallic metalorganic layer by exposing said portion to air and heating said portion to a temperature of between 450° C. and 500° C. for between 2 to 4 hours to form a growth catalyst on the substrate; and
exposing the substrate to a carbon precursor gas at a deposition temperature to form single wall carbon nanotubes.

### Claim 2 (depends on 1)

The method of claim 1, wherein the bimetallic or trimetallic metalorganic layer comprises a metalorganic selected from: iron phthalocyanine, molybdenum phthalocyanine, nickel phthalocyanine, copper phthalocyanine, or a combination thereof.

### Claim 3 (depends on 1)

The method of claim 1, wherein the bimetallic or trimetallic metalorganic layer is deposited by a physical vapor deposition process.

### Claim 4 (depends on 1)

The method of claim 1, wherein the deposition mask comprises a metal oxide.

### Claim 5 (depends on 1)

The method of claim 1, wherein the deposition mask comprises a substance selected from silicon oxide or aluminum oxide.

### Claim 6 (depends on 1)

The method of claim 1, wherein the unmasked portion of the substrate has a top surface comprising a metal oxide.

### Claim 7 (depends on 6)

The method of claim 6, wherein the metal oxide is selected from the group consisting of silicon oxide, aluminum oxide, and magnesium oxide.

### Claim 8 (depends on 1)

The method of claim 1, wherein the growth catalyst comprises metal growth catalyst particles.

### Claim 9 (depends on 1)

The method of claim 1, wherein the carbon precursor gas comprises methane.

### Claim 10 (depends on 1)

The method of claim 1, wherein exposing the substrate to a carbon precursor gas comprises exposing the substrate to an atmosphere comprising methane, argon, and hydrogen.

### Claim 11 (depends on 10)

The method of claim 10, wherein the substrate is exposed to the carbon precursor gas for between 15 minutes and 60 minutes.

### Claim 12 (depends on 1)

The method of claim 1, wherein the deposition temperature is 700° C.

### Claim 13 (depends on 1)

The method of claim 1, wherein the bimetallic or trimetallic metalorganic layer is produced by deposition of a metalorganic substance and the metalorganic substance is purified prior to deposition of the bimetallic or trimetallic metalorganic layer.

### Claim 14 (depends on 1)

The method of claim 1, wherein the exposing said portion of the bimetallic or trimetallic metalorganic layer to air is performed prior to removing the deposition mask from the substrate.