Photocatalytic coating and method of making same

Patent metadata

Field	Value
Publication number	US-2017291169-A1
Application number	US-201515507714-A
Country	US
Kind code	A1
Filing date	Aug 28, 2015
Priority date	Aug 29, 2014
Publication date	Oct 12, 2017
Grant date	—

Abstract

Described herein are methods for coating a substrate with a photocatalytic compound, and photocatalytic elements prepared by these methods.

First claim

What is claimed is:

1 . A method for making a photocatalytic element comprising:
(a) coating a substrate with an inorganic silicon oxide precursor solution, comprising a silsesquioxane having predominantly cage form characteristics, and a solvent; (b) a first curing of the coated substrate at a temperature sufficient to remove the solvent and retain silsesquioxane cage form characteristics; (c) coating the coated substrate with a dispersion comprising a photocatalytic material to form a plural coated substrate; and (d) a second curing of the plural coated substrate at a temperature sufficient to immobilize at least a portion of the photocatalytic material above the surface of the coated substrate; (e) wherein at least some of the silsesquioxane is converted to create a silicon dioxide interface with the substrate as a result of the first curing or the second curing.

2 . The method of claim 1 , wherein the silicon oxide precursor solution is a flowable oxide solution.

3 . The method of claim 1 , wherein the solvent is selected from methyl isobutyl ketone, 2-pentanone, methyl isopropyl ketone and diisobutyl ketone.

4 . The method of claim 1 , wherein the inorganic silicon precursor solution is FOX®-17.

5 . The method of claim 1 , wherein the first curing step is less than 235° C. for about 4 min to about 90 min.

6 . The method of claim 1 , wherein the first curing step is less than about 235° C. for about 30 min.

7 . The method of claim 1 , wherein the second curing step is by thermal curing, exposure to an oxygen plasma source, or exposure to an electron beam.

8 . The method of claim 1 , wherein the second curing is by thermal curing at about 100° C. to about 450° C.

9 . The method of claim 1 , wherein the second curing is by thermal curing at about 200° C. to about 600° C.

10 . The element of claim 1 , wherein the photocatalytic material is selected from copper oxide loaded plural-phase titanium oxide, copper oxide loaded Sn/C/N-doped titanium oxide, and unloaded doped titanium oxide.

11 . The method of claim 1 , wherein the photocatalytic material comprises WO 3 and CeO 2 .

12 . The method of claim 1 , wherein comprising spin-coating the substrate or the coated substrate.

13 . The method of claim 1 , wherein the photocatalytic element contains less than 1% of carbon, based upon the total number of non-hydrogen atoms present.

14 . A photocatalytic element made according to the method of claim 1 .

15 . A photocatalytic element comprising:
a substrate;
an intermediate layer comprising a silsesquioxane and silicon dioxide; and
a photocatalytic layer comprising a photostable inorganic photocatalyst;
wherein the intermediate layer is disposed between the substrate layer and the photocatalytic layer; and
the intermediate layer is adhered to both the substrate layer and the photocatalytic layer.

16 . The photocatalytic element of claim 14 , wherein the photocatalytic layer comprises WO 3 .

17 . The photocatalytic element of claim 15 , wherein the photocatalytic layer further comprises CeO 2 .

18 . The photocatalytic element of claim 14 , wherein the silsesquioxane comprises hydrogen silsesquioxane.

19 . The photocatalytic element of claim 14 , wherein the silsesquioxane is inorganic.

20 . The photocatalytic element of claim 14 , wherein the intermediate layer comprises a silicon dioxide interface with a surface of the substrate.

21 . The photocatalytic element of claim 15 , wherein the intermediate layer is covalently bonded to the substrate layer or the photocatalytic layer.

22 . The photocatalytic element of claim 15 , wherein the intermediate layer is covalently bonded to the substrate layer and the photocatalytic layer.

23 . The photocatalytic element of claim 15 , wherein the intermediate layer is fused to the substrate layer or the photocatalytic layer.

24 . The photocatalytic element of claim 15 , wherein the intermediate layer is porous.

25 . The photocatalytic element of claim 15 , wherein the photocatalytic element contains less than 2% of carbon, based upon the total number of non-hydrogen atoms present.

26 . The method of claim 1 , wherein the silicon dioxide interface with a surface of the substrate comprises one or more covalent bonds between the silicon dioxide and the surface of the substrate.

Assignees

• Nitto Denko Corp

Inventors

• Mukherjee Rajesh

Classifications

• B01J37/344

  of electromagnetic wave energy · CPC title

• B01J23/30

  Tungsten · CPC title

• B01J23/72

  Copper · CPC title

• B32B2255/20

  Inorganic coating · CPC title

• B01J21/063

  Titanium; Oxides or hydroxides thereof · CPC title