Nanowire-nanoparticle conjugate photolytic fuel generators

• US 9,067,201 B2
• Filed: 10/21/2010
• Issued: 06/30/2015
• Est. Priority Date: 10/21/2009
• Status: Active Grant

• Current Assignee: Board of Regents of Oklahoma State University
• Original Assignee: Board of Regents of Oklahoma State University
• Inventors: Kalkan, Ali Kaan
• Primary Examiner(s): Hendricks, Keith
• Assistant Examiner(s): Raphael, Colleen M
• Application Number:
  US13/502,956
• Publication Number:
  US 20120205251A1
• Time in Patent Office: 1,713 Days
• Field of Search: 422/186
• US Class Current: 1/1
• CPC Class Codes: B01J 23/6482 Vanadium
• CPC Class Codes: B01J 23/682 with vanadium, niobium, tantalum or polonium
• CPC Class Codes: B01J 35/23 in a colloidal state
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 35/393 Metal or metal oxide crystallite size
• CPC Class Codes: B01J 35/58 Fabrics or filaments
• CPC Class Codes: B01J 37/036 to form a gel or a cogel
• CPC Class Codes: C01B 3/042 Decomposition of water
• CPC Class Codes: C25B 1/55 Photoelectrolysis
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

A method for generating hydrogen is disclosed. The method includes substantially submersing nanowires having metallic nanoparticles into water, exposing the water submerged nanowires to light, and collecting hydrogen gas produced by photolysis from the exposure to light.

Claims

1. A method of generating hydrogen comprising:

submersing vanadium semiconductor decorated nanowires decorated with plasmonic metallic nanoparticles into water, the plasmonic nanoparticles decorating the nanowires such that exposure to light outside the nanowire creates electron/hole pairs with the nanowire functioning as an anode and splitting water molecules into oxygen molecules and hydrogen ions using hole transfer, and the plasmonic metallic nanoparticles functioning as cathodes that transport the electrons to the hydrogen ions reducing them to hydrogen gas;

exposing the water submerged nanowires to light;

and collecting hydrogen gas produced by photolysis from the exposure to light.

2. The method of claim 1, wherein the metallic nanoparticles comprise gold.

3. The method of claim 1, wherein the metallic nanoparticles comprise silver.

4. The method of claim 1, wherein the metallic nanoparticles comprise copper.

5. The method of claim 1, wherein the metallic nanoparticles comprise platinum.

6. The method of claim 1, further comprising preparing semiconductor nanowires by supercritical drying of vanadia gel.

7. A system for production of hydrogen gas via hydrolysis comprising:

a water based medium;

a plurality of vanadium semiconductor nanowires in the medium; and

plasmonic nanoparticles decorating the nanowires such that exposure to light outside the nanowire creates electron/hole pairs;

wherein the nanowire functions as an anode and splits water molecules into oxygen molecules and hydrogen ions using hole transfer; and

wherein the plasmonic nanoparticles function as cathodes that transport the electrons to the hydrogen ions reducing them to hydrogen gas.

8. The system of claim 7, wherein the nanoparticles comprise gold.

9. The system of claim 7, wherein the nanoparticles comprise silver.

10. The system of claim 7, wherein the nanoparticles comprise copper.

11. The system of claim 7, wherein the nanoparticles have the characteristic of localized surface plasmon resonance.

12. The system of claim 7, wherein the nanoparticles couple the incident electromagnetic radiation to nanowire waveguide modes for optical absorption enhancement.

13. The system of claim 7, wherein the nanoparticles function as near field concentrators for enhancing the absorption of electromagnetic radiation in the nanowires.

14. A method of generating hydrogen from water by photolysis comprising:

preparing a plurality of vanadium semiconductor nanowires decorated with plasmonic nanoparticles functioning as near field concentrators enhancing the absorption of light in the nanowires;

immersing the plurality of nanowires in a water solution;

exposing the solution to light thereby creating electron/hole pairs in the nanowires, the nanowires functioning as anodes that split the water molecules into oxygen molecules and hydrogen ions using hole transfer and the plasmonic nanoparticles functioning as cathodes that transport electrons to reduce resultant hydrogen ions into hydrogen molecules.

15. The method of claim 14, wherein preparing a plurality of semiconductor nanowires further comprises supercritical drying of vanadia gel.

16. The method of claim 15, wherein preparing a plurality of semiconductor nanowires further comprises immersing the nanowires into a metallic salt solution.

17. The method of claim 14, wherein exposing the solution to light further comprises exposing the solution to solar radiation.