Templated synthesis of metal nanorods in silica nanotubes

Patent metadata

Field	Value
Publication number	US-9937556-B2
Application number	US-201214358127-A
Country	US
Kind code	B2
Filing date	Nov 15, 2012
Priority date	Nov 15, 2011
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A method of preparing a metal nanorod. The method includes seeding a metal nanoparticle within the lumen of a nanotube, and growing a metal nanorod from the seeded metal nanoparticle to form a metal nanorod-nanotube composite. In some cases, the nanotube includes metal binding ligands attached to the inner surface. Growing of the metal nanorod includes incubating the seeded nanotube in a solution that includes: a metal source for the metal in the metal nanorod, the metal source including an ion of the metal; a coordinating ligand that forms a stable complex with the metal ion; a reducing agent for reducing the metal ion, and a capping agent that stabilizes atomic monomers of the metal. Compositions derived from the method are also provided.

First claim

What is claimed is:

1. A method of preparing a metal nanorod, comprising:
seeding a metal nanoparticie within the lumen of a close-ended nanotube; and
growing a metal nanorod from the seeded metal nanoparticie to form a metal nanorod-nanotube composite,
wherein the close-ended nanotube is closed at both ends,
wherein the nanotube is a silica nanotube.

2. The method of claim 1 , wherein the metal nanoparticle comprises Au, Ag, Pt, Pd, Ir, Rh, or Ru, or a combination thereof.

3. The method of claim 1 , wherein the metal nanorod comprises Au, Ag, Co, Cu, Os, Ni, Pb, Pt, Pd, Ir, Rh, Sn, Mn, Fe, Zn or Ru, or a combination thereof.

4. The method of claim 1 , wherein the nanotube comprises an inner surface that is functionalized with a metal binding ligand comprising an amino group, thiol group, phosphate group, sulfate group, sulfonate group, or carboxylate group, or a combination thereof.

5. The method of claim 1 , wherein the seeding comprises incubating the nanotube with a precursor of the metal nanoparticle and then reducing the precursor to form the metal nanoparticle within the lumen of the close-ended nanotube.

6. The method of claim 1 , wherein the growing comprises incubating a nanotube in a solution comprising
a metal source for a metal in the metal nanorod, the metal source comprising an ion of the metal,
a coordinating ligand that forms a stable complex with the metal ion,
a reducing agent for reducing the metal ion, and
a capping agent that stabilizes atomic monomers of the metal.

7. The method of claim 6 , wherein the coordinating ligand is potassium iodide (KI) when the metal is Au, the coordinating ligand is acetonitrile when the metal is Ag, or the coordinating ligand is NaNO 2 when the metal is Pt.

8. The method of claim 6 , wherein the capping agent is polyvinylpyrrolidone.

9. The method of claim 1 , further comprising removing the nanotube from the metal nanorod-nanotube composite.

10. The method of claim 9 , wherein the removing of the nanotube comprises etching of the metal nanorod-nanotube composite in solution or gaseous etchant.

11. The method of claim 1 , wherein after the seeding and prior to the growing, the method further comprises etching or purifying, or both etching and purifying, the seeded nanotube.

12. The method of claim 11 , wherein the etching comprises incubating the seeded nanotube in NaOH.

13. The method of claim 1 , further comprising preparing the silica nanotube by coating a rod-shaped nanocrystal with a silica layer or with an organosilicate layer and a silica layer, then removing the rod-shaped nanocrystal to form the silica nanotube.

14. The method of claim 13 , wherein the coating comprises sol-gel formation of the silica layer and/or the organosilicate layer.

15. The method of claim 14 , wherein the sol-gel formation comprises hydrolyzing and condensing a silicon alkoxide onto the nanocrystal to form the silica layer, or hydrolyzing and condensing an amino-containing organosilane onto the nanocrystal to form the organosilicate layer, followed by hydrolyzing and condensing a silicon alkoxide onto the organosilicate layer to form the silica layer.

16. The method of claim 15 , wherein the organosilane is 2-aminopropyltriethoxysilane and the silicon alkoxide is tetraethyl orthosilicate.

Assignees

• Univ California

Inventors

• Yin Yadong
• Gao Chuanbo

Classifications

• Y10T428/2993

  Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.] · CPC title

• B22F1/004 Primary

  Operations & Transport · mapped topic

• Y10S977/902

  Specified use of nanostructure · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• Y10T428/296

  Rubber, cellulosic or silicic material in coating · CPC title