Efficient hydrogen production by photocatalytic water splitting using surface plasmons in hybrid nanoparticles

• US 20120145532A1
• Filed: 12/23/2011
• Published: 06/14/2012
• Est. Priority Date: 07/24/2009
• Status: Abandoned Application

• Current Assignee: UNM Rainforest Innovations (f/k/a STC.UNM) (The University of New Mexico)
• Original Assignee: UNM Rainforest Innovations (f/k/a STC.UNM) (The University of New Mexico)
• Inventors: Smolyakov, Gennady A., Osinski, Marek A.
• Application Number:
  US13/374,364
• Publication Number:
  US 20120145532A1
• Time in Patent Office: Days
• US Class Current: 204/157.44
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 23/60 with zinc, cadmium or mercury
• CPC Class Codes: B01J 23/6484 Niobium
• CPC Class Codes: B01J 23/80 with zinc, cadmium or mercury
• CPC Class Codes: B01J 23/8474 Niobium
• CPC Class Codes: B01J 35/23 in a colloidal state
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 35/397 Egg shell like
• CPC Class Codes: B01J 35/398 Egg yolk like
• CPC Class Codes: B01J 35/45 Nanoparticles
• CPC Class Codes: B01J 37/035 Precipitation on carriers
• CPC Class Codes: C01B 3/042 Decomposition of water
• 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

Photocatalytic water splitting is employed as a method to directly obtain clean hydrogen from solar radiation by using hybrid nanoparticles with metallic cores and semiconductor photocatalytic shells. Efficient unassisted overall photocatalytic splitting of water is based on resonant absorption from surface plasmon in metal core/semiconductor shell hybrid nanoparticles, which can extend the absorption spectra further towards the visible-near infrared range, thus dramatically increasing the solar energy conversion efficiency. When used in combination with scintillator nanoparticles, the hybrid photocatalytic nanoparticles can be used for conversion of nuclear energy into hydrogen.

Claims

1. A method of producing hydrogen, comprising photocatalytically splitting water using nanoparticles comprising a metal core and semiconductor shell or layer on the core.

2. The method of claim 1 wherein the metal core of the nanoparticles can have different shapes and sizes.

3. The method of claim 1 wherein the metal core comprises a noble metal core or an alloyed noble metal core.

4. The method of claim 3 wherein the noble metal core comprises Ag, Au, Pt, or Pd, or an alloy of those, or an alloy of those with Ni.

5. The method of claim 1 wherein the semiconductor shell or layer is transparent to optical excitation in the visible and near-infrared spectral ranges consistent with the plasmon absorption bands of the metal core.

6. The method of claim 1 wherein the semiconductor shell or layer is selected from the group consisting of TiO₂, ZnS, and Nb₂O₅.

7. The method of claim 1 wherein a co-catalyst is provided on the semiconductor shell or layer.

8. The method of claim 1 wherein the nanoparticles are irradiated with solar radiation.

9. The method of claim 1 wherein the nanoparticles are irradiated with light energy from scintillators irradiated with nuclear radiation.

10. The method of claim 9 wherein the scintillators comprise scintillator nanoparticles.

11. The method of claim 9 wherein the nuclear radiation is provided by generated nuclear waste.

12. The method of claim 9 wherein the nuclear radiation is provided by a nuclear reactor.

13. A water-based dispersion of nanoparticles comprising a metal core and semiconductor shell or layer on the core wherein the nanoparticles can photocatalytically split the water.

14. The dispersion of claim 13 wherein the metal core of the nanoparticles can have different shapes and sizes.

15. The dispersion of claim 13 wherein the metal core comprises a noble metal core or an alloyed noble metal core.

16. The dispersion of claim 15 wherein the noble metal core comprises Ag, Au, Pt, or Pd, or an alloy of those, or an alloy of those with Ni.

17. The dispersion of claim 13 wherein a co-catalyst is provided on the semiconductor shell or layer.

18. The dispersion of claim 13 wherein the semiconductor shell or layer is selected from the group consisting of TiO₂, ZnS, and Nb₂O₅.

19. The dispersion of claim 13 further including scintillator nanoparticles.

20. The dispersion of claim 19 wherein the scintillator nanoparticles are co-dispersed with the photocatalytic nanoparticles.

21. A nanoparticle comprising a metal core and a semiconductor shell or layer on the core for use in photocatalytic splitting of water wherein the shell or layer is transparent to optical excitation in the visible and near-infrared spectral ranges, consistent with the plasmon absorption bands of the metal core.

22. The nanoparticle of claim 21 wherein the metal core can have a shape of sphere, disk, or rod and a dimension in the range of 1 nm to 100 nm.

23. The nanoparticle of claim 21 wherein the metal core comprises a noble metal core or an alloyed noble metal core.

24. The nanoparticle of claim 21 wherein the noble metal core comprises Ag, Au, Pt, or Pd, or an alloy of those, or an alloy of those with Ni.

25. The nanoparticle of claim 21 wherein a co-catalyst is provided on the shell or layer.

26. The nanoparticle of claim 21 wherein the semiconductor shell or layer is selected from the group consisting of TiO₂, ZnS, and Nb₂O₅.