Methods of Making Binary Metal Oxide Nanostructures and Methods of Controlling Morphology of Same

• US 20100278720A1
• Filed: 05/04/2010
• Published: 11/04/2010
• Est. Priority Date: 05/04/2009
• Status: Active Grant

• Current Assignee: Hongjun Zhou, Stanislaus S. Wong
• Original Assignee: Hongjun Zhou, Stanislaus S. Wong
• Inventors: Zhou, Hongjun, Wong, Stanislaus S.
• Granted Patent: US 8,318,126 B2
• Time in Patent Office: Days
• US Class Current: 423/604
• CPC Class Codes: B01J 23/06 of zinc, cadmium or mercury
• CPC Class Codes: B01J 23/72 Copper
• CPC Class Codes: B01J 23/745 Iron
• CPC Class Codes: B01J 35/23 in a colloidal state
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 35/58 Fabrics or filaments
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01G 1/02 Oxides
• CPC Class Codes: C01G 3/02 Oxides; Hydroxides
• CPC Class Codes: C01G 49/06 Ferric oxide [Fe2O3]
• CPC Class Codes: C01G 9/02 Oxides; Hydroxides
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/82 by IR- or Raman-data
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C01P 2004/13 Nanotubes
• CPC Class Codes: C01P 2006/42 Magnetic properties

Abstract

The present invention includes a method of producing a crystalline metal oxide nanostructure. The method comprises providing a metal salt solution and providing a basic solution; placing a porous membrane between the metal salt solution and the basic solution, wherein metal cations of the metal salt solution and hydroxide ions of the basic solution react, thereby producing a crystalline metal oxide nanostructure.

Claims

1. A method of producing a crystalline metal oxide nanostructure, the method comprising:

providing a metal salt solution and providing a basic solution;

placing a porous membrane between the metal salt solution and the basic solution, wherein metal cations of the metal salt solution and hydroxide ions of the basic solution react, thereby producing a crystalline metal oxide nanostructure.

2. A method of claim 1 wherein the metal salt in the metal salt solution is selected from the group consisting of zinc salt, copper salt, iron salt, cobalt salt, nickel salt, magnesium salt, manganese salt, scandium salt, thallium salt, tin salt, aluminum salt, cadmium salt, and chromium salt.

3. A method of claim 1 wherein the metal salt in the metal salt solution is selected from the group consisting of yttrium salt, zirconium salt, vanadium salt, ruthenium salt, tungsten salt, bismuth salt, barium salt, calcium salt, strontium salt, osmium salt, gallium salt, germanium salt, antimony salt, niobium salt, rhenium salt and lead salt.

4. The method of claim 1 wherein the metal oxide nanostructure is single crystalline.

5. The method of claim 1 wherein the metal oxide nanostructure is polycrystalline.

6. The method of claim 1 wherein metal cations and hydroxide ions predominantly nucleate to form metal hydroxides within the confines of the pores.

7. The method of claim 1 wherein the metal cations and hydroxide ions predominantly nucleate at the walls of the pores.

8. The method of claim 1 wherein the basic solution has a pH of greater than or equal to 13, the membrane is a polycarbonate membrane, and zinc oxide nanowires are produced.

9. The method of claim 1 wherein the basic solution has a pH of greater than or equal to 13, the membrane is a polycarbonate membrane, and copper oxide nanowires are produced.

10. The method of claim 1 wherein the basic solution has a pH of greater than or equal to 13, the membrane is an alumina membrane, and hematite nanotubes are produced.

11. The method of claim 1 wherein the method further comprises controlling the dimensions and morphology of the nanostructures,

wherein homogeneous type membrane encourages formation of nanowires or nanorods;

wherein heterogeneous type membrane encourages formation of nanotubes;

wherein as the pH of the basic solution increases, the length of one-dimensional nanostructures increases;

wherein as the temperature of the reaction increases, the length of one-dimensional nanostructures increases;

wherein the reaction can proceed until nanowires form when using homogeneous type membrane.

12. A crystalline metal oxide nanostructure having the formula M_xO_z, wherein x is 1, 2, 3, 4 or 5, and y is 2, 3, 4, 7 or 8, and wherein M is selected from the group consisting of Zn, Cu, Fe, Co, Ni, Mg, Mn, Sc, Tl, Sn, Al, Cd and Cr, wherein the nanostructure has a high degree of purity, and wherein the nanostructure is a nanotube, a nanowire or nanorod.

13. The single crystalline metal oxide nanostructure of claim 12 wherein x is 1 or 2, and y is 1 or 3.

14. The metal oxide nanostructure of claim 12 wherein the metal oxide nanostructure is single crystalline.

15. The metal oxide nanostructure of claim 12 wherein the metal oxide nanostructure is polycrystalline.

16. A nanoarray comprising a plurality of crystalline metal oxide nanostructures wherein the chemical formula of the nanostructures is M_xO_z wherein x is 1, 2, 3, 4 or 5, and y is 2, 3, 4, 7 or 8, and wherein M is selected from the group consisting of Zn, Cu, Fe, Co, Ni, Mg, Mn, Sc, Tl, Sn, Al, Cd and Cr, wherein the nanostructures have a high degree of purity, wherein the nanostructures are nanowires, nanotubes, or mixtures thereof.

17. The nanoarray of claim 16 wherein x is 1 or 2, and y is 1 or 3.

18. The nanoarray of claim 16 wherein the metal oxide nanostructure is single crystalline.

19. The nanoarray of claim 16 wherein the metal oxide nanostructure is polycrystalline.

20. The nanoarray of claim 16 wherein the nanoarray is at least 50% monodisperse.