Nanoelectrodes for water splitting

• US 10,626,511 B2
• Filed: 05/25/2017
• Issued: 04/21/2020
• Est. Priority Date: 05/25/2016
• Status: Active Grant

• Current Assignee: University of Southern California
• Original Assignee: University of Southern California
• Inventors: Wu, Wei, Wang, Yifei
• Primary Examiner(s): Smith, Nicholas A
• Application Number:
  US15/605,805
• Publication Number:
  US 20170342577A1
• Time in Patent Office: 1,062 Days
• CPC Class Codes: B01J 19/088 giving rise to electric discharges for heating purposes H05B7/00; for the production of ozone C01B13/11, H01T19/00
• CPC Class Codes: B01J 2219/0809 employing two or more electrodes
• CPC Class Codes: B01J 2219/0841 Metal
• CPC Class Codes: B01J 2219/0843 Ceramic
• CPC Class Codes: B01J 2219/0877 Liquid
• CPC Class Codes: C25B 1/04 by electrolysis of water
• CPC Class Codes: C25B 11/057 consisting of a single element or compound
• CPC Class Codes: C25B 13/04 characterised by the material
• CPC Class Codes: C25B 9/73 of the filter-press type
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

In various embodiments, the invention teaches a method for water splitting with much higher efficiency than previous methods. By decreasing the distance between two electrodes to nanometer scale, even shorter than the electric field screening length, the external power required for water splitting is significantly reduced.

Claims

1. A nanoelectrode system for generating hydrogen from water, comprising:

an anode comprising multiple prongs; and

a cathode,

wherein the anode and the cathode are separated by a distance of 10 nm 40 nm.

2. The system of claim 1, further comprising a dielectric material situated between the anode and the cathode, wherein the dielectric material is 10 nm 40 nm thick.

3. The system of claim 2, wherein the system has a metal-insulator-metal (MIM) structure.

4. The system of claim 2, wherein the dielectric material comprises silicon nitride.

5. The system of claim 2, further comprising a substrate in contact with the cathode.

6. The system of claim 5, wherein the substrate comprises silicon.

7. The system of claim 2, wherein the system is a vertical nanoelectrode system.

8. The system of claim 1, wherein a portion of the anode is coated with a dielectric material.

9. The system of claim 1, wherein the cathode comprises a metal.

10. The system of claim 9, wherein the metal is Ti or Pt, or a combination thereof.

11. The system of claim 1, wherein the anode comprises a metal.

12. The system of claim 11, wherein the metal is Ti, Au, Ni, or indium-tin-oxide (ITO), or a combination thereof.

13. The system of claim 1, further comprising water.

14. The system of claim 13, wherein the water does not have electrolytes.

15. A method for generating hydrogen from water, comprising:

applying an electric current to the system of claim 13 so as to create an electric field between the anode and cathode and thereby generating hydrogen from the water.

16. The system of claim 1, wherein the system is a horizontal nanoelectrode system.

17. The system of claim 1, wherein the cathode comprises multiple prongs.

18. The system of claim 1, comprising at least two anodes, each anode comprising multiple prongs.

19. A composition for generating hydrogen from water, comprising:

an anode comprising multiple prongs, a cathode, a substrate in contact with the cathode, and a dielectric material situated between the anode and the cathode, wherein the dielectric material is 10 nm-40 nm thick.

20. A method for fabricating a nanoelectrode device, comprising:

depositing a cathode metal on a substrate to provide a cathode;

depositing a dielectric material on said cathode, wherein said dielectric material is 10 nm-40 nm thick;

depositing an anode metal on said dielectric material to provide an anode, wherein the anode comprises multiple prongs; and

etching the dielectric material.

21. The method of claim 20, wherein the etching comprises using a low-DC bias reactive-ion etching (RIE) process.