Photocatalytic apatite composition as well as production method and article thereof

Abstract

The photocatalytic apatite composition and its production method are disclosed. The photocatalytic apatite comprises a photocatalytic apatite having incorporated into the apatite crystal structure thereof a metal oxide having a photocatalytic action, such as titanium oxide, and a metal ion having an antimicrobial property, such as a silver ion or a copper ion. The photocatalyst apatite composition is capable of maintaining excellent decomposition and adsorption properties for various organic materials such as VOCs or specific adsorbing substances such as a virus for a long time and, at the same time, expressing an excellent antimicrobial property in a dark place as well as under daylight.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart showing one preferred embodiment of the production method of a photocatalytic apatite composition according to the present invention;

FIG. 2 is a flow chart showing another preferred embodiment of the production method of a photocatalytic apatite composition according to the present invention;

FIG. 3 is a graph plotting the evaluation results of photocatalytic activity of different silver-doped photocatalytic apatites produced in the examples; and

FIG. 4 is a graph plotting the evaluation results of antimicrobial property, in a dark place, of different silver-doped photocatalytic apatites produced in the examples.

Claims

1. A photocatalytic apatite composition comprising a photocatalytic apatite having incorporated into the apatite crystal structure thereof a metal oxide having a photocatalytic action and a metal ion having an antimicrobial property.

2. The photocatalytic apatite composition as defined in claim 1, wherein the metal ion is a silver ion and/or a copper ion.

3. The photocatalytic apatite composition as defined in claim 1 or 2, wherein the metal ion is doped into the apatite crystal structure by a dipping method or a coprecipitation method.

4. The photocatalytic apatite composition as defined in claim 1 or 2, wherein after the metal ion is doped into the apatite crystal structure, the photocatalytic apatite is further thermally treated at a temperature of 300° C. or more.

5. The photocatalytic apatite composition as defined in claim 1 or 2, wherein the metal ion constituting the metal oxide is titanium.

6. The photocatalytic apatite composition as defined in claim 1 or 2, wherein the metal ion is contained in an amount of 10 mol % or less in terms of the ratio to the metal ion in the apatite crystal.

7. The photocatalytic apatite composition as defined in claim 1 or 2, wherein the apatite is calcium hydroxyapatite.

8. The photocatalytic apatite composition as defined in claims 1 or 2, which takes the form of a powder.

9. The photocatalytic apatite composition as defined in claim 1 or 2, which takes the form of a coating material.

10. A method for producing a photocatalytic apatite composition comprising a photocatalytic apatite having incorporated into the apatite crystal structure thereof a metal oxide having a photocatalytic action and a metal ion having an antimicrobial property, the production method comprising: preparing a photocatalytic apatite having incorporated into the apatite crystal structure thereof a metal ion having a photocatalytic action,preparing a solution of a metal salt originated from a metal ion having an antimicrobial property,dipping the photocatalytic apatite in the metal salt solution to perform ion exchange, andthermally treating the resulting reaction product at a temperature of 300° C. or more.

11. A method for producing a photocatalytic apatite composition comprising a photocatalytic apatite having incorporated into the apatite crystal structure thereof a metal oxide having a photocatalytic action and a metal ion having an antimicrobial property, the production method comprising: preparing a solution comprising starting materials necessary for preparing a photocatalytic apatite having incorporated into the apatite crystal structure thereof a metal ion having a photocatalytic action, and comprising a metal salt derived from a metal ion having an antimicrobial property,reacting the starting materials and the metal salt by a coprecipitation method in the presence of aqueous ammonia, andthermally treating the resulting reaction product at a temperature of 300° C. or more.

12. The method for producing a photocatalytic apatite composition as defined in claim 10 or 11, wherein the metal ion is silver ion and/or copper ion.

13. The method for producing a photocatalytic apatite composition as defined in claim 10 or 11, wherein the apatite is calcium hydroxyapatite.

14. An article having photocatalytic and antimicrobial properties, comprising the photocatalytic apatite composition defined in claim 1 or 2.

15. The article as defined in claim 14, wherein the photocatalytic apatite composition is coated as a thin film on the surface of the article.

16. The article as defined in claim 14, wherein the photocatalytic apatite composition is blended in the constituent material of the article.