Systems and methods related to the formation of carbon-based nanostructures
Systems and methods for the formation of carbon-based nanostructures are generally described. In some embodiments, the nanostructures may be formed on a nanopositor. The nanopositor can comprise, in some embodiments, at least one of metal atoms in a non-zero oxidation state and metalloid atoms in a non-zero oxidation state. For example, the nanopositor may comprise a metal oxide, a metalloid oxide, a metal chalcogenide, a metalloid chalcogenide, and the like. The carbon-based nanostructures may be grown by exposing the nanopositor, in the presence or absence of a growth substrate, to a set of conditions selected to cause formation of carbon-based nanostructures on the nanopositor. In some embodiments, metal or metalloid atoms in a non-zero oxidation state are not reduced to a zero oxidation state during the formation of the carbon-based nanostructures. In some cases, metal or metalloid atoms in a non-zero oxidation state do not form a carbide during the formation of the carbon-based nanostructures.
1. A method of growing carbon nanotubes, comprising:
exposing a carbon nanotube precursor to a nanopositor comprising a zirconium oxide under conditions causing the formation of carbon nanotubes directly on the zirconium oxide.
2. The method of claim 1 , wherein fewer than about 2% of the zirconium atoms in the zirconium oxide are reduced to a zero oxidation state during the formation of the carbon nanotubes.
3. The method of claim 1 , wherein fewer than about 2% of the zirconium atoms in the zirconium oxide form a zirconium carbide during the formation of the carbon nanotubes.
4. The method of claim 1 , wherein the zirconium oxide has an oxygen to zirconium ratio ranging from about 1.0 to about 2.0.
5. The method of claim 1 , wherein the precursor material comprises at least one of a hydrocarbon and an alcohol.
6. The method of claim 1 , wherein the set of conditions comprises a pressure substantially equal to or less than about 1 atmosphere.
7. The method of claim 1 , wherein the set of conditions comprises a temperature between about 300-1100° C.
8. The method of claim 1 , wherein the nanopositor comprises a dopant.
9. The method of claim 8 , wherein the dopant comprises at least one of Ca, Mg, Sr, Ba, Y, and Mo.
10. The method of claim 8 , wherein the nanopositor comprises between about 0.1 atomic % and about 5 atomic % calcium.
11. The method of claim 1 , wherein fewer than about 1% of the zirconium atoms in the zirconium oxide are reduced to a zero oxidation state during the formation of the carbon nanotubes.
12. The method of claim 1 , wherein fewer than about 0.1% of the zirconium atoms in the zirconium oxide are reduced to a zero oxidation state during the formation of the carbon nanotubes.
13. The method of claim 1 , wherein substantially none of the zirconium atoms in the zirconium oxide are reduced to a zero oxidation state during the formation of the carbon nanotubes.
14. The method of claim 1 , wherein fewer than about 1% of the zirconium atoms in the zirconium oxide form a zirconium carbide during the formation of the carbon nanotubes.
15. The method of claim 1 , wherein fewer than about 0.1% of the zirconium atoms in the zirconium oxide form a zirconium carbide during the formation of the carbon nanotubes.
16. The method of claim 1 , wherein substantially none of the zirconium atoms in the zirconium oxide form a zirconium carbide during the formation of the carbon nanotubes.
17. The method of claim 1 , wherein the zirconium oxide has an oxygen to zirconium ratio ranging from about 1.6 to about 2.0.
18. The method of claim 1 , wherein the zirconium oxide comprises ZrO 2 .
19. The method of claim 1 , wherein the nanopositor is in contact with a growth substrate.
20. The method of claim 1 , wherein the exposing step comprises exposing the nanopositor to a carbon nanotube precursor material such that the precursor material contacts the nanopositor.
21. The method of claim 1 , wherein the set of conditions comprises a temperature between about 500-900° C.