Nanostructured photocatalysts and doped wide-bandgap semiconductors

• US 9,873,115 B2
• Filed: 07/01/2014
• Issued: 01/23/2018
• Est. Priority Date: 07/01/2013
• Status: Active Grant

• Current Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Original Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Inventors: Nagpal, Prashant, Singh, Vivek, Castellanos Beltran, Ignacio, Alivov, Yahya, Ding, Yuchen, Cerkovnik, Logan Jerome
• Primary Examiner(s): Hailey, Patricia L.
• Application Number:
  US14/902,725
• Publication Number:
  US 20160193595A1
• Time in Patent Office: 1,302 Days
• Field of Search: 502215, 502216, 502220, 977700, 977755, 977773, 977774
• CPC Class Codes: B01J 23/72 Copper
• CPC Class Codes: B01J 27/04 Sulfides
• CPC Class Codes: B01J 27/047 with chromium, molybdenum, tungsten or polonium
• CPC Class Codes: B01J 27/051 Molybdenum
• CPC Class Codes: B01J 27/0573 Selenium; Compounds thereof
• CPC Class Codes: B01J 35/23 in a colloidal state
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 35/40 characterised by dimensions, e.g. grain size in a colloidal state B01J35/23; crystallite size B01J35/77
• CPC Class Codes: C01G 11/02 Sulfides
• CPC Class Codes: C01P 2004/16 Nanowires or nanorods, i.e. solid nanofibres with two nearly equal dimensions between 1-100 nanometer
• CPC Class Codes: C01P 2004/51 Particles with a specific particle size distribution
• CPC Class Codes: C25B 1/04 by electrolysis of water
• CPC Class Codes: C25B 11/091 consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
• CPC Class Codes: C25B 3/25 Reduction
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
• CPC Class Codes: Y02P 20/133 Renewable energy sources, e.g. sunlight

Abstract

Photocatalysts for reduction of carbon dioxide and water are provided that can be tuned to produce certain reaction products, including hydrogen, alcohol, aldehyde, and/or hydrocarbon products. These photocatalysts can form artificial photosystems and can be incorporated into devices that reduce carbon dioxide and water for production of various fuels. Doped wide-bandgap semiconductor nanotubes are provided along with synthesis methods. A variety of optical, electronic and magnetic dopants (substitutional and interstitial, energetically shallow and deep) are incorporated into hollow nanotubes, ranging from a few dopants to heavily-doped semiconductors. The resulting wide-bandgap nanotubes, with desired electronic (p- or n-doped), optical (ultraviolet bandgap to infrared absorption in co-doped nanotubes), and magnetic (from paramagnetic to ferromagnetic) properties, can be used in photovoltaics, display technologies, photocatalysis, and spintronic applications.

Claims

1. A catalyst for reduction of carbon dioxide and water comprising:

nanostructured titanium dioxide doped with one of;

copper, wherein the nanostructured titanium dioxide forms a p-type semiconductor;

nitrogen, wherein the nanostructured titanium dioxide forms a p-type semiconductor;

niobium, copper indium sulfide nanoparticles having a diameter of 3 nm to 4.6 nm, wherein the copper indium sulfide nanoparticles are attached to a surface of the nanostructured titanium dioxide;

molybdenum disulfide nanosheets, wherein the nanostructured titanium dioxide is in the form of nanotubes and the titanium dioxide nanotubes are coated by the molybdenum disulfide nanosheets; and

cadmium sulfide nanoparticles having a diameter of about 3 nm to about 5 nm, wherein the nanostructured titanium dioxide is in the form of nanotubes and the titanium dioxide nanotubes are coated by the cadmium sulfide nanoparticles.

2. The catalyst of claim 1, wherein the nanostructured titanium dioxide is in the form of nanoparticles.

3. The catalyst of claim 2, wherein the titanium dioxide nanoparticles have a diameter of about 10 nm to about 15 nm.

4. The catalyst of claim 1, wherein the nanostructured titanium dioxide is doped with the copper indium sulfide nanoparticles.

5. The catalyst of claim 4, wherein a loading of copper indium sulfide is about 14% by weight.

6. The catalyst of claim 4, wherein the nanostructured titanium dioxide is comprised by nanoparticles and about three quantum dots of copper indium sulfide are attached per titanium dioxide nanoparticle.

7. The catalyst of claim 1, wherein the nanostructured titanium dioxide is in the form of nanotubes.

8. The catalyst of claim 7, wherein the titanium dioxide nanotubes are doped with nitrogen.

9. The catalyst of claim 7, wherein the titanium dioxide nanotubes are coated by the copper indium sulfide nanoparticles.

10. The catalyst of claim 7, wherein the titanium dioxide nanotubes are coated by the molybdenum disulfide nanosheets.

11. The catalyst of claim 1, wherein the molybdenum disulfide nanosheets are substantially two-dimensional nanostructures having a thickness from about 1 nm to about 100 nm.

12. The catalyst of claim 1, wherein the nanostructured titanium dioxide is doped with at least about 5% by weight copper.

13. The catalyst of claim 1, wherein the nanostructured titanium dioxide is doped with at least about 5% by weight nitrogen.

14. The catalyst of claim 1, wherein the nanostructured titanium dioxide is doped with niobium.

15. The catalyst of claim 14, wherein the nanostructured titanium dioxide is doped with at least about 10% by weight niobium.

16. The catalyst of claim 14, wherein the nanostructured titanium dioxide forms an n-type semiconductor.

17. A catalyst for reduction of carbon dioxide and water comprising:

nanostructured cadmium sulfide, wherein at least a portion of a surface of the nanostructured cadmium sulfide is coated with zinc selenide.

18. The catalyst of claim 17, wherein the nanostructured cadmium sulfide is comprised by nanorods.

19. The catalyst of claim 18, wherein the nanorods have a length of at least about 20 nm.

20. The catalyst of claim 18, wherein the cadmium sulfide nanorods have a quantum confined bandgap of about 2.68 eV and bandedge photoluminescence of about 2.62 eV.

21. The catalyst of claim 17, wherein the nanostructured cadmium sulfide is comprised by nanoparticles.

22. The catalyst of claim 21, wherein the cadmium sulfide nanoparticles have a diameter of about 3 nm to about 8 nm.

23. A catalyst for reduction of carbon dioxide and water comprising:

nanostructured cadmium sulfide, wherein the nanostructured cadmium sulfide is comprised by nanorods and the cadmium sulfide nanorods comprise a metal-hybrid.

24. The catalyst of claim 23, wherein the metal comprises one of silver and gold.

25. The catalyst of claim 23, wherein the metal-hybrid is grown at an end of the cadmium sulfide nanorods.

26. A catalyst for reduction of carbon dioxide and water comprising:

nanostructured titanium dioxide doped with copper, wherein the nanostructured titanium dioxide forms a p-type semiconductor.

27. A catalyst for reduction of carbon dioxide and water comprising:

nanostructured titanium dioxide doped with nitrogen, wherein the nanostructured titanium dioxide forms a p-type semiconductor.