Synthesis of high quality carbon single-walled nanotubes
AssigneeHonda Motor Co., Ltd.
InventorsAvetik R. Harutyunyan, Oleg Kuznetsov
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Abstract
Methods and processes for synthesizing high quality carbon single-walled nanotubes (SWNTs) are provided. A carbon precursor gas at reduced concentration (pressure) is contacted with a catalyst deposited on a support and at temperature about 10° C. above the SWNT synthesis onset temperature, but below the thermal decomposition temperature of the carbon precursor gas for given growth conditions. The concentration (pressure) of the carbon precursor gas can be controlled by reducing the total pressure of the gas, or by diluting with an inert carrier gas, or both. The methods produce SWNTs with the ratio of G-band to D-band in Raman spectra (IG:ID) of about 5 to about 200.
Claims13
A method for synthesizing carbon single-walled nanotubes (SWNTs), the method comprising the steps of:
- providing a metal catalyst on a support wherein the metal catalyst and the support are in a mass ratio of between about 1:1 to about 1:500;
- contacting the catalyst with a carbon-containing gas selected from a group consisting of methane, ethane, propane, butane, pentane and hexane at a partial pressure of about 5 torr to about 200 torr, and the total pressure of the gas is about 740 torr to about 780 torr;
- and
- providing a reaction temperature between about 600° C. and 1200° C., wherein SWNTs are synthesized with a ratio of G-band to D-band in Raman spectra (IG:ID) of greater than about 100,
- wherein the partial pressure of the methane, ethane, propane, butane, pentane or hexane is 180 torr and the gas has a total pressure of 780 torr.
Dependencies are inferred from the claim text.