Multivalence semiconductor photocatalytic materials

Patent metadata

Field	Value
Publication number	US-2017291170-A1
Application number	US-201515510621-A
Country	US
Kind code	A1
Filing date	Sep 11, 2015
Priority date	Sep 12, 2014
Publication date	Oct 12, 2017
Grant date	—

Abstract

Described herein are heterogeneous materials comprising a p-type semiconductor comprising two metal oxide compounds of the same metal in two different oxidation states and an n-type semiconductor having a deeper valence band than the p-type semiconductor valence bands, wherein the semiconductor types are in ionic communication with each other. The heterogeneous materials enhance photocatalytic activity.

First claim

1 . A heterogeneous material comprising:
a p-type semiconductor comprising a first metal oxide compound and a second metal oxide compound, wherein the first metal oxide compound and the second metal oxide compound have different oxidation states of the same metal, and wherein the p-type semiconductor has a p-type valence band; a first n-type semiconductor having an n-type valence band which is deeper than the p-type valence band, wherein the first n-type semiconductor is in ionic charge communication with the p-type semiconductor.

2 . The heterogeneous material of claim 1 , further comprising a second n-type semiconductor.

3 . The heterogeneous material of claim 1 , wherein the first n-type semiconductor is TiO 2 .

4 . The heterogeneous material of claim 1 , wherein the first n-type semiconductor is a combination of anatase TiO 2 and rutile TiO 2 .

5 . The heterogeneous material of claim 1 , wherein the first n-type semiconductor comprises WO 3 .

6 . The heterogeneous material of claim 1 , wherein the molar ratio of the first n-type semiconductor to the second n-type semiconductor is about 0.5 to about 10.

7 . The heterogeneous material of claim 1 , wherein the second n-type semiconductor is CeO 2 , GeO 2 , SnO 2 , or ZrO 2 .

8 . The heterogeneous material of claim 1 , wherein the second n-type semiconductor is CeO 2 .

9 . The heterogeneous material of claim 1 , wherein the second n-type semiconductor is GeO 2 .

10 . The heterogeneous material of claim 1 , wherein the second n-type semiconductor is SnO 2 .

11 . The heterogeneous material of claim 1 , wherein the p-type semiconductor comprises Cu x O.

12 . The heterogeneous material of claim 1 , wherein the p-type semiconductor is about 0.001% to about 5% of the heterogeneous material by weight.

13 . The heterogeneous material of claim 1 , wherein the p-type semiconductor is Cu x O, and is about 0.01% to about 1% of the heterogeneous material by weight.

14 . The heterogeneous material of claim 1 , wherein at least 50% of the p-type semiconductor is loaded onto the surface of particles of the first n-type semiconductor and particles of the second n-type semiconductor.

15 . The heterogeneous material of claim 1 , wherein the heterogeneous material is in the form of a powder.

16 . A method of preparing a heterogeneous material comprising:
heating a mixture of:
1) a first n-type semiconductor and a second n-type semiconductor; and
2) an aqueous solution comprising a copper ion complex;

wherein the first n-type semiconductor and the second n-type semiconductor are mixed prior to combining the first n-type semiconductor and the second n-type semiconductor with the aqueous solution comprising the copper ion complex.

17 . The method of claim 16 , further comprising filtering the heterogeneous material out of the mixture of the after the mixture has been heated.

18 . A method of decomposing a chemical compound, comprising exposing the chemical compound to a photocatalyst comprising the heterogeneous material of claim 1 in the presence of light.

19 . The method of claim 18 , wherein the chemical compound is a pollutant.

20 . A method of killing a microbe, comprising exposing the microbe to a photocatalyst comprising the heterogeneous material of claim 1 in the presence of light.

21 . The heterogeneous material of claim 1 , wherein the second n-type semiconductor is SnO 2 .

Assignees

• Nitto Denko Corp

Inventors

• Sambandan Ekambaram
• Zhang Bin

Classifications

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J2235/15

  X-ray diffraction · CPC title

• B01J35/34

  Mechanical properties · CPC title

• B01J27/1817

  with copper, silver or gold · CPC title

• B01J37/04

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