Visible light sensitive photocatalyst, method of producing the same, and electrochemical water decomposition cell, water decomposition system, and organic material decomposition system each including the same

Patent metadata

Field	Value
Publication number	US-9718695-B2
Application number	US-201213517766-A
Country	US
Kind code	B2
Filing date	Jun 14, 2012
Priority date	Jun 15, 2011
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A visible light sensitive photocatalyst including a compound represented by Formula 1:

A a-x M 1 x Si b-y M 2 y O c   Formula 1

wherein A is one or more metals selected from Ag, Cu, and Au; M 1 is one or more metals selected from Li, Na, K, Rb, and Cs; M 2 is one or more metals selected from Ge, Sn, Ti, Zr, and Hf, and 1.7≦a≦2.3, 0.7≦b≦1.3, 2.7≦c≦3.3, 0≦x<a, and 0≦y<b.

First claim

What is claimed is:

1. A visible light sensitive photocatalyst film comprising a compound represented by Formula 1 on a substrate:
A a-x M 1 x Si b-y M 2 y O c   Formula 1

wherein
A is one or more metals selected from Ag, Cu, and Au,
M 1 is one or more metals selected from Li, Na, K, Rb, and Cs,
M 2 is one or more metals selected from Ge, Sn, Ti, Zr, and Hf,
1.7≦a≦2.3, 0.7≦b≦1.3, 2.7≦c≦3.3, 0≦x<a, and 0≦y<b, and
the compound of Formula 1 has an orthorhombic crystal structure.

2. The visible light sensitive photocatalyst of claim 1 , wherein a band gap energy of the compound of Formula 1 is about 2 to about 3 electron volts.

3. The visible light sensitive photocatalyst of claim 1 , wherein an energy level of a valence band of the compound of Formula 1 is about 0.5 to about 3 electron volts higher than an oxidation potential of water.

4. The visible light sensitive photocatalyst of claim 1 , wherein the compound of Formula 1 is an n-type semiconductor.

5. The visible light sensitive photocatalyst of claim 1 , wherein, in the compound of Formula 1, a distance between adjacent A atoms, a distance between a first A atom and a first M 1 atom, or a distance between adjacent M 1 atoms is smaller than a corresponding Van der Waals distance therebetween.

6. The visible light sensitive photocatalyst of claim 1 , wherein an electron effective mass of the compound of Formula 1 satisfies the inequality 0.3×m 0 ≦m e *≦1.5×m 0 , wherein m 0 is a rest mass of a free electron and m e * is the electron effective mass.

7. The visible light sensitive photocatalyst of claim 1 , wherein a hole effective mass of the compound of Formula 1 satisfies the inequality 2×m 0 ≦m h *≦5×m 0 , wherein m 0 is a rest mass of a free electron and m h * is the hole effective mass.

8. The visible light sensitive photocatalyst of claim 1 , wherein the compound of Formula 1 is Ag 2 Si b-y Ge y O 3 , wherein 0.9≦b≦1.1 and 0≦y<0.4.

9. The visible light sensitive photocatalyst of claim 1 , wherein the compound of Formula 1 is Ag 2 SiO 3 .

10. The visible light sensitive photocatalyst of claim 8 , wherein a distance between adjacent Ag atoms in the compound of Formula 1 is smaller than 3.44 angstroms.

11. A water splitting system comprising:
a transparent case;
an aqueous solution in the transparent case, wherein the aqueous solution comprises the visible light sensitive photocatalyst comprising a compound represented by Formula 1:
A a-x M 1 x Si b-y M 2 y O c   Formula 1

wherein
A is one or more metals selected from Ag, Cu, and Au,
M 1 is one or more metals selected from Li, Na, K, Rb, and Cs,
M 2 is one or more metals selected from Ge, Sn, Ti, Zr, and Hf,
1.7≦a≦2.3, 0.7≦b≦1.3, 2.7≦c≦3.3, 0≦x<a, and 0≦y<b, and
the compound of Formula 1 has an orthorhombic crystal structure; and

a light source for irradiating white light into the aqueous solution.

12. The water splitting system of claim 11 , further comprising a sacrificial reagent in the aqueous solution.

13. The water splitting system of claim 12 , wherein the sacrificial reagent is one or more selected from AgNO 3 , FeCl 3 , Fe(NO 3 ) 3 , Na 2 S 2 O 8 , Ce(SO 4 ) 2 , HgCl 2 , Na 3 PW 12 O 40 , and Na 3 PMo 12 O 40 .

14. An organic material decomposition system comprising:
a transparent case,
a solution in the transparent case, the solution comprising an organic material and the visible light sensitive photocatalyst comprising a compound represented by Formula 1:
A a-x M 1 x Si b-y M 2 y O c   Formula 1

wherein
A is one or more metals selected from Ag, Cu, and Au,
M 1 is one or more metals selected from Li, Na, K, Rb, and Cs,
M 2 is one or more metals selected from Ge, Sn, Ti, Zr, and Hf,
1.7≦a≦2.3, 0.7≦b≦1.3, 2.7≦c≦3.3, 0≦x<a, and 0≦y<b,
the compound of Formula 1 has an orthorhombic crystal structure; and

a light source for irradiating white light into the solution.

15. A method of producing a visible light sensitive photocatalyst, the method comprising:
combining BaCO 3 and SiO 2 to prepare a BaSiO 3 ;
combining the BaSiO 3 and AgNO 3 to provide a mixture;
heating and ion-exchanging the mixture to produce the light sensitive photocatalyst represented by Formula 1:
A a-x M 1 x Si b-y M 2 y O c   Formula 1

wherein
A is one or more metals selected from Ag, Cu, and Au,
M 1 is one or more metals selected from Li, Na, K, Rb, and Cs,
M 2 is one or more metals selected from Ge, Sn, Ti, Zr, and Hf,
1.7≦a≦2.3, 0.7≦b≦1.3, 2.7≦c≦3.3, 0≦x<a, and 0≦y<b, and
the light sensitive photocatalyst of Formula 1 has an orthorhombic crystal structure; and

disposing the light sensitive photocatalyst on a substrate to produce the visible light sensitive photocatalyst film.

16. The method of claim 15 , wherein the heating of the mixture comprising BaSiO 3 and AgNO 3 is conducted in air at a temperature of about 290 to about 350° C. for about 5 to about 100 hours.

17. The method of claim 15 , wherein the light sensitive photocatalyst is sensitive to visible light.

18. A method of producing a visible light sensitive photocatalyst film, the method comprising:
preparing a BaSiO 3 paste;
disposing the BaSiO 3 paste on a substrate;
heat-treating the substrate and the BaSiO 3 paste to provide a heat-treated substrate;
disposing AgNO 3 on the heat-treated substrate; and
heat-treating the substrate and the AgNO 3 to produce the light sensitive photocatalyst on the substrate to produce the light sensitive photocatalyst film,
wherein the visible light sensitive photocatalyst is represented by Formula 1:
A a-x M 1 x Si b-y M 2 y O c   Formula 1

wherein
A is one or more metals selected from Ag, Cu, and Au,
M 1 is one or more metals selected from Li, Na, K, Rb, and Cs,
M 2 is one or more metals selected from Ge, Sn, Ti, Zr, and Hf,
1.7≦a≦2.3, 0.7≦b≦1.3, 2.7≦c≦3.3, 0≦x<a, and 0≦y<b, and
the visible light sensitive photocatalyst of Formula 1 has an orthorhombic crystal structure; and

disposing light sensitive photocatalyst on a substrate to produce the visible light sensitive photocatalyst film.

19. The method of claim 18 , wherein the preparing of the BaSiO 3 paste comprises combining BaSiO 3 and a terpineol mixture comprising about 0.1 to about 20 weight percent of ethyl cellulose, based on a total weight of the terpineol mixture.

20. The method of claim 18 , wherein the heat-treating of the substrate and the AgNO 3 comprises heating the substrate and the AgNO 3 in air at a temperature of about 290 to about 350° C. for about 5 to about 100 hours.

21. The method of claim 18 , wherein the AgNO 3 is a powder.

22. The method of claim 18 , wherein the light sensitive photocatalyst film is sensitive to visible light and is Ag 2 SiO 3 .

23. A visible light sensitive photocatalyst comprising:
a substrate; and a visible light sensitive photocatalyst disposed on the substrate, the visible light sensitive photocatalyst comprising
a first metal, wherein the first metal is one or more metals selected from Li, Na, K, Rb, and Cs;
a second metal, wherein the second metal is one or more metals selected from Ag, Cu, and Au;
a third metal, wherein the third metal is one or more metals selected from Ge, Sn, Ti, Zr, and Hf;
Si; and oxygen,
wherein each mole of the photocatalyst comprises
x moles of the first metal,
(a-x) moles of the second metal,
y moles of the third metal,
(b

Assignees

• Kim Tae-Gon
• Kim Tae-Hyung
• Im Seoung-Jae
• Samsung Electronics Co Ltd

Inventors

• Kim Tae-Gon
• Kim Tae-Hyung
• Im Seoung-Jae

Classifications

• B01J19/123

  Ultraviolet light · CPC title

• B01J2219/0877

  Liquid · CPC title

• C01B33/20 Primary

  Silicates (persilicates C01B15/14 {; containing aluminium C01B33/26}) · CPC title

• B01J37/0081

  Preparation by melting · CPC title

• C25B1/003

  Chemistry & Metallurgy · mapped topic