Tethered transition metals promoted photocatalytic system for efficient hydrogen evolutions

Patent metadata

Field	Value
Publication number	US-9579639-B2
Application number	US-201414477414-A
Country	US
Kind code	B2
Filing date	Sep 4, 2014
Priority date	Sep 5, 2013
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

The present invention is directed, at least in part, to a process for improving the efficiency of a photocatalyst (a semiconductor photocatalyst) by tethering (depositing) a metal (e.g., metal ions of a late transition metal, such as nickel) to the semiconductor (photocatalyst) surface through the use of an organic ligand. More specifically, 1,2-ethanedithiol (EDT) functions as an excellent molecular linker (organic ligand) to attach a transition metal complex (e.g., nickel (Ni 2+ ions)) to the semiconductor surface, which can be in the form of a cadmium sulfide surface. The photocatalyst has particular utility in generating hydrogen from H 2 S.

First claim

What is claimed is:

1. A process for producing a photocatalyst that is capable of converting H 2 S into hydrogen and sulfur comprising the steps of:
preparing a photocatalyst material comprising CdS; and
using an organic ligand to attach a transition metal species to a surface of the photocatalyst material without the formation of a dopant layer.

2. The process of claim 1 , wherein the organic ligand comprises 1,2-ethanedithiol (EDT).

3. The process of claim 1 , wherein the transition metal comprises Ni 2+ .

4. The process of claim 1 , wherein the transition metal species comprises a late transition metal species.

5. The process of claim 1 , wherein the step of using the organic ligand to attach the transition metal species comprises the steps of:
adding 1,2-ethanedithiol (EDT) to a first solution containing the CdS photocatalyst material to form a first mixture;
forming CdS precipitates from the first mixture;
redispersing the CdS precipitates in a second solution to form a suspension;
adding Ni(NO 3 ) 2 to the suspension; and
forming a CdS photocatalyst material that has Ni-EDT species attached to a surface thereof.

6. The process of claim 5 , wherein the first and second solutions comprise ethanol.

7. A photocatalyst made in accordance with the process of claim 1 .

8. A process for producing a photocatalyst that is capable of converting H 2 S into hydrogen and sulfur comprising the steps of:
providing a photocatalyst material; and
decorating the surface of the photocatalyst with a transition metal species using an organic ligand without the formation of a dopant layer, wherein the organic ligand comprises 1,2-ethaneodithiol (EDT) and wherein the step of decorating the surface comprises:
adding the organic ligand to a first solution containing the photocatalyst material to form a first mixture having precipitates;
washing the first mixture with ethanol;
redispersing the precipitates in a second solution to form a suspension;
adding the transition metal species to the suspension; and
washing the suspension with ethanol to form a photocatalyst material having a transition metal-organic ligand species attached to a surface thereof.

9. The process of claim 8 , wherein the transition metal species comprises a late transition metal species.

10. The process of claim 8 , wherein the photocatalyst material comprises CdS and the transition metal species comprises Ni 2+ .

11. The process of claim 10 , wherein the first and second solutions comprise ethanol.

12. The process of claim 10 , wherein the transition metal-organic ligand species is a Ni-EDT species.

13. A photocatalyst made in accordance with the process of claim 8 .

14. A process for producing a photocatalyst that is capable of converting H 2 S into hydrogen and sulfur comprising the steps of:
preparing a photocatalyst material; and
using an organic ligand to attach a transition metal species to a surface of the photocatalyst material without the formation of a dopant layer, wherein the organic ligand comprises 1,2-ethanedithiol (EDT).

Assignees

• Univ King Abdullah Sci & Tech
• Saudi Arabian Oil Co

Inventors

• Takanabe Kazuhiro
• Isimjan Tayirjan
• Yu Weili
• Del Gobbo Silvano
• Xu Wei

Classifications

• B01J2531/847

  Nickel · CPC title

• B01J31/2273

  with only nitrogen as heteroatomic ring members, e.g. 1,3-diarylimidazoline-2-ylidenes · CPC title

• B01J37/038

  to form slurries or suspensions, e.g. a washcoat · CPC title

• B01J31/226 Primary

  Sulfur, e.g. thiocarbamates · CPC title

• B01J37/04 Primary

  Mixing {(B01J37/0009, B01J37/0018 take precedence)} · CPC title