Synthesis of carbon nanostructures

• US 20060051282A1
• Filed: 09/03/2004
• Published: 03/09/2006
• Est. Priority Date: 09/03/2004
• Status: Abandoned Application

• Current Assignee: Hong Kong University of Science and Technology
• Original Assignee: Hong Kong University of Science and Technology
• Inventors: Wang, Ning, Sheng, Ping, Liang, Qi, Tang, Zikang, Chan, Che Ting, Miao, Jian Ying, Zhal, Jianpang
• Application Number:
  US10/933,779
• Publication Number:
  US 20060051282A1
• Time in Patent Office: Days
• US Class Current: 423/445.R
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01B 2202/02 Single-walled nanotubes
• CPC Class Codes: C01B 32/16 Preparation

Abstract

A method for forming carbon nanostructures is disclosed. The method includes the steps of: (a) synthesising a microporous template material comprising crystals having no dimension greater than about 2 μm, (b) heating the crystals in the presence of an inert gas or a mixture of an inert gas and a carbon-containing gas at a temperature of between 500° C. and 900° C., and (c) recovering carbon nanostructures by washing the heated crystals in an acid to remove the template material.

Claims

1. A method for forming carbon nanostructures, comprising the steps of:

(a) synthesising a microporous template material comprising crystals having no dimension greater than about 2 μ

m, (b) heating said crystals in the presence of an inert gas or a mixture of an inert gas and a carbon-containing gas at a temperature of between 500°

C. and 900°

C., and (c) recovering carbon nanostructures by washing the heated crystals in an acid to remove the template material.

2. A method as claimed in claim 1 wherein the synthesis of the template material is carried out using a water/alcohol mixture as a solvent.

3. A method as claimed in claim 1 wherein a carbon containing precursor is introduced into the template material during the synthesis of the template material.

4. A method as claimed in claim 3 wherein the carbon containing precursor is selected from the group consisting of:

tetrapropylammonium, tetraethylammonium, choline, 2-picoline, 3-picoline, 4-picoline, triethylamine, tripropylamine, N,N-dimethylbenzylamine, piperidine, N-methylpiperidine, 3-methylpiperidine, cyclohexylamine, N-methylcyclohexylamine, 3-methylpiperidine, cyclohexylamine, N-methylcyclohexylamine, dicyclohexylamine, triethanolamine, N,N-diethylethanolamine, N,N′

-dimethylpiperazine, 1,4-diazabicyclo-(2,2,2)octane, N,N-dimethylethanolamine, N-methyldiethanolamine, and N-methylethanolamine.

5. A method as claimed in claim 1 wherein atoms of Si, Co, Ti, or Cr are incorporated into the lattice structure of the template material during synthesis of the template material.

6. A method as claimed in claim 1 wherein the flow-rate of the inert gas or inert gas plus carbon containing gas is between 100 ml/min to 500 ml/min.

7. A method as claimed in claim 1 wherein a carbon-containing gas is present in step (b) and said carbon containing gas is selected from the group consisting of:

methane, ethane, propane, butane, ethylene, propylene, acetylene, cyclohexane, carbon monoxide, or mixtures thereof.

8. A method as claimed in claim 1 wherein prior to step (b) the crystals are preheated from room temperature to the temperature of step (b) under the protection of an inert gas.

9. A method as claimed in claim 1 wherein the acid washing is performed using HCl, HNO₃, HF, H₂SO₄.

10. A method as claimed in claim 9 wherein the acid washing is performed using a reflux process.

11. A method as claimed in claim 1 wherein the template material comprises microporous aluminophosphate AlPO₄-5 crystals (AFI).

12. A method as claimed in claim 11 wherein the template material is selected from the group consisting of:

Si-AFI, Co-AFI, Cr-AFI and Ti-AFI.

13. A method as claimed in claim 1 wherein the template material is Faujasite, LTA, SBA-15 or 13X.