Method for forming aluminum oxide/carbon nanotubes by ultrasonic atomization and chemical vapor deposition

• US 9,834,444 B2
• Filed: 04/25/2017
• Issued: 12/05/2017
• Est. Priority Date: 03/22/2016
• Status: Expired due to Fees

• Current Assignee: King Fahd University Of Petroleum And Minerals
• Original Assignee: King Fahd University Of Petroleum And Minerals
• Inventors: Rabbani, Fahad Ali, Malaibari, Zuhair Omar, Atieh, Muataz Ali
• Primary Examiner(s): MCCRACKEN, DANIEL
• Application Number:
  US15/496,732
• Publication Number:
  US 20170275168A1
• Time in Patent Office: 224 Days
• Field of Search: 4234471-4473, 423445 B, 977742-754, 977842-848
• 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 2202/06 Multi-walled nanotubes
• CPC Class Codes: C01B 2202/10 Filled nanotubes
• CPC Class Codes: C01B 2202/32 Specific surface area
• CPC Class Codes: C01B 32/16 Preparation
• CPC Class Codes: C01B 32/162 characterised by catalysts
• CPC Class Codes: C01F 7/304 of organic aluminium compounds
• CPC Class Codes: C04B 41/4531 by C.V.D.
• CPC Class Codes: C23C 16/01 on temporary substrates, e.g. substrates subsequently removed by etching
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/4417 Methods specially adapted for coating powder
• CPC Class Codes: C23C 16/4486 by producing an aerosol and subsequent evaporation of the droplets or particles
• CPC Class Codes: C23C 16/46 characterised by the method used for heating the substrate C23C16/48, C23C16/50 take precedence
• CPC Class Codes: C23C 16/463 Cooling of the substrate
• CPC Class Codes: Y10S 977/744 having atoms interior to the carbon cage
• CPC Class Codes: Y10S 977/752 Multi-walled
• CPC Class Codes: Y10S 977/843 Gas phase catalytic growth, i.e. chemical vapor deposition
• CPC Class Codes: Y10S 977/846 internal modifications, e.g. filling, endohedral modifications

Abstract

A vertical chemical vapor deposition (CVD) reactor and a method for synthesizing metal oxide impregnated carbon nanotubes. The CVD reactor includes a preheating zone portion and a reaction zone portion, and preferably an additional cooling zone portion and a product collector. The method includes (a) subjecting a liquid reactant solution comprising an organic solvent, a metallocene, and a metal alkoxide to atomization in the presence of a gas flow comprising a carrier gas and a support gas to form an atomized mixture, and (b) heating the atomized mixture to a temperature of 200° C.-1400° C., wherein the heating forms a metal oxide and at least one carbon source compound, wherein the metallocene catalyzes the formation of carbon nanotubes from the at least one carbon source compound and the metal oxide is incorporated into or on a surface of the carbon nanotubes to form the metal oxide impregnated carbon nanotubes.

Claims

1. A method of synthesizing carbon nanotubes impregnated with aluminum oxide, the method comprising:

(a) ultrasonically atomizing a liquid reactant solution in the presence of at least one gas flow comprising at least one carrier gas and at least one support gas, wherein the liquid reactant solution comprises at least one organic solvent, at least one metallocene, and aluminum isopropoxide, to form an atomized mixture comprising droplets of the liquid reactant solution and the at least one gas flow, and

(b) heating the atomized mixture to a temperature of 200°

C.-1400°

C. in a chemical vapor deposition reactor, wherein the heating forms aluminum oxide and at least one carbon source compound, wherein the at least one metallocene catalyzes the formation of carbon nanotubes from the at least one carbon source compound and the aluminum oxide is incorporated into or on a surface of the carbon nanotubes to form the carbon nanotubes impregnated with the aluminum oxide,

wherein 1-99 wt % of the aluminum oxide incorporated into or on the surface of the carbon nanotubes is in corundum phase.

2. The method of claim 1, further comprising collecting the carbon nanotubes impregnated with the aluminum oxide.

3. The method of claim 1, wherein the at least one carrier gas is at least one selected from the group consisting of He, N₂, and Ar.

4. The method of claim 1, wherein the at least one support gas is selected from the group consisting of CO₂, H₂O, H₂ and NH₃.

5. The method of claim 1, wherein the at least one organic solvent is selected from the group consisting of 2-methoxy ethanol, 2-ethoxy ethanol, 2-methoxy propanol, 2-ethoxy propanol, 2-propoxy propanol, 2-butoxy propanol, 2-butoxy butanol, cyclohexane, heptane, octane, benzene, toluene, ethyl benzene, xylene, cumene, and styrene.

6. The method of claim 1, wherein the at least one metallocene is selected from the group consisting of a metallocene of Ni, a metallocene of Co, a metallocene of Fe, a metallocene of Cr, a metallocene of Mo, a metallocene of Rh, a metallocene of Ti, a metallocene of W, a metallocene of V, and a metallocene of Zr.

7. The method of claim 1, wherein the carbon nanotubes are multi-walled carbon nanotubes, and wherein the multi-walled carbon nanotubes impregnated with the aluminum oxide have a BET surface area of 450-2000 m²/g.