Multi-layered water-splitting photocatalyst having a plasmonic metal layer with optimized plasmonic effects

Patent metadata

Field	Value
Publication number	US-2018318799-A1
Application number	US-201615773376-A
Country	US
Kind code	A1
Filing date	Nov 8, 2016
Priority date	Nov 16, 2015
Publication date	Nov 8, 2018
Grant date	—

Abstract

Photocatalysts and methods of using the same for producing hydrogen and oxygen from water are disclosed. The photocatalysts include a photoactive layer having a thickness of 10 nanometers (nm) to 1000 nm and a plasmonic metal layer having a thickness of 2 nm to 20 nm and having surface plasmon resonance properties in response to ultra-violet and/or visible light, wherein the plasmonic metal layer is positioned proximal to the photoactive layer.

First claim

1 . A photocatalyst comprising:
a substrate; a photoactive layer having a thickness of 10 nanometers (nm) to 1000 nm; and a plasmonic metal layer having a thickness of 2 nm to 20 nm and having surface plasmon resonance properties in response to ultra-violet and/or visible light, wherein the plasmonic metal layer is coated on the substrate and the photoactive layer is coated on the plasmonic metal layer.

2 . The photocatalyst of claim 1 , wherein the plasmonic metal layer has a thickness of 4 nm to 12 nm, preferably 6 nm to 10 nm, more preferably from 7 nm to 9 nm, or most preferably about 8 nm.

3 . The photocatalyst of claim 1 , wherein the plasmonic metal layer is a discontinuous layer having a plurality of noncontiguous regions each having a thickness of less than 10 nm or a continuous layer having a thickness of at least 10 nm.

4 . The photocatalyst of claim 3 , wherein the combined surface area of the plurality of noncontiguous regions is up to 30% of the surface area of the photoactive layer.

5 . The photocatalyst of claim 1 , wherein the plasmonic metal layer is gold, silver, copper, or an alloy thereof.

6 . The photocatalyst of claim 1 , wherein the plasmonic metal layer is gold.

7 . The photocatalyst of claim 1 , wherein the thickness of the photoactive layer is 100 nm to 500 nm, preferably, 200 nm to 400 nm, or more.

8 . The photocatalyst of claim 1 , wherein the photoactive layer is a titanium dioxide layer, a zinc oxide layer, or a cadmium sulfide layer, or a layer having any combination of titanium dioxide, zinc oxide, and/or cadmium sulfide.

9 . The photocatalyst of claim 8 , wherein the photoactive layer is a titanium dioxide layer having anatase, rutile, brookite, or a mixture thereof, preferably anatase or a mixed-phase comprising anatase and rutile.

10 . The photocatalyst of claim 9 , wherein the ratio of anatase to rutile is 1.5:1 to 10:1.

11 . The photocatalyst of claim 1 , wherein the photoactive layer is impregnated with a metal that is less than 5, 4, 3, 2, 1, 0.5 or 0.1 wt. % of the total weight of the photoactive layer selected from palladium, silver, platinum, gold, rhodium, ruthenium, rhenium, iridium, nickel, or copper, or any combinations or oxides or alloys thereof.

12 . The photocatalyst of claim 1 , wherein the plasmonic metal layer is in direct contact with the photoactive layer.

13 . The photocatalyst of claim 1 , wherein at least one interlayer is positioned between the plasmonic metal layer and the photoactive layer.

14 . The photocatalyst of claim 13 , wherein the interlayer is a metal oxide layer, preferably a SiO 2 layer.

15 . The photocatalyst of claim 1 , wherein the photocatalyst is capable of catalyzing the photocatalytic electrolysis of water.

16 . An aqueous composition comprising the photocatalyst of claim 1 .

17 . A water-splitting system for generating hydrogen from water, the system comprising a reaction vessel comprising water and any one of the photocatalysts of claim 1 .

18 . A method for enhancing the electric field produced at an interface between a photoactive layer having a thickness of 10 nanometers (nm) to 1000 nm and a plasmonic metal layer having a thickness of 2 nm to 20 nm and having surface plasmon resonance properties in response to ultra-violet and/or visible light, the method comprising coating the plasmonic layer on a substrate, and subsequently coating the plasmonic metal layer on the photoactive layer.

19 . The method of claim 18 , wherein the plasmonic metal layer has a thickness of 4 nm to 12 nm, preferably 6 nm to 10 nm, more preferably from 7 nm to 9 nm, or most preferably about 8 nm.

20 . The method of claim 18 , wherein the plasmonic metal layer is a discontinuous layer having a plurality of noncontiguous regions each having a thickness of less than 10 nm or a continuous layer having a thickness of at least 10 nm.

Assignees

• Sabic Global Technologies Bv

Inventors

• Khan Mohd Adnan
• Al-Oufi Maher
• Idriss Hicham

Classifications

• B01J23/52 Primary

  Gold · CPC title

• C23C14/185

  by cathodic sputtering · CPC title

• B01J23/42

  Platinum · CPC title

• B01J19/123

  Ultraviolet light · CPC title

• B01J21/063

  Titanium; Oxides or hydroxides thereof · CPC title