Ultrafine particle of rutile-type titanium oxide

Abstract

It is provided ultrafine particles of a rutile titanium oxide obtained by maintaining the pH of an aqueous solution of a titanium compound having a Ti concentration of from 0.07 to 5 mol/L in the range of −1 to 3 in the presence of a chelating agent. Such ultrafine particles of a rutile titanium oxide are useful for photocatalysts, high refractive index materials, ultraviolet absorbing materials and the like.

1 . Ultrafine particles of a rutile-type titanium oxide obtained by maintaining the pH of an aqueous solution of a titanium compound having a Ti concentration of 0.07 to 5 mol/L in the range of −1 to 3 in the presence of a chelating agent.  
     
     
         2 . The ultrafine particles of a rutile-type titanium oxide according to  claim 1 , wherein the chelating agent as set forth in  claim 1  is one or more selected from hydroxycarboxylic acids, diketones, keto esters and dicarboxylic acids.  
     
     
         3 . The ultrafine particles of a rutile-type titanium oxide according to  claim 2 , wherein the hydroxycarboxylic acid is glycolic acid, lactic acid, citric acid, tartaric acid or salts thereof.  
     
     
         4 . The ultrafine particles of a rutile-type titanium oxide according to  claim 2 , wherein the diketone is acetylacetone or salts thereof.  
     
     
         5 . The ultrafine particles of a rutile-type titanium oxide according to  claim 1 , wherein the chelating agent is added in a mole ratio of the chelating agent to titanium of 0.0005 to 0.05.  
     
     
         6 . A photocatalyst containing the ultrafine particles of a rutile-type titanium oxide according to  claim 1 .  
     
     
         7 . The photocatalyst according to  claim 6 , which is calcined at 100 to 800 degree centigrade.  
     
     
         8 . A method for preparing ultrafine particles of a rutile-type titanium oxide, comprising maintaining the pH of an aqueous solution of a titanium compound having a Ti concentration of 0.07 to 5 mol/L in the range of −1 to 3 in the presence of a chelating agent.  
     
     
         9 . The method according to  claim 8 , wherein the chelating agent is one or more selected from hydroxycarboxylic acids, diketones, keto esters and dicarboxylic acids.  
     
     
         10 . The method according to  claim 9 , wherein the hydroxycarboxylic acid is glycolic acid, lactic acid, citric acid, tartaric acid or salts thereof.  
     
     
         11 . The method according to  claim 9 , wherein the diketone is acetylacetone or salts thereof.  
     
     
         12 . The method according to  claim 8 , comprising adding the chelating agent in a mole ratio of the chelating agent to titanium of 0.0005 to 0.05.  
     
     
         13 . An aggregate comprising ultrafine particles of a rutile-type titanium oxide obtained by maintaining the pH of an aqueous solution of a titanium compound having a Ti concentration of 0.07 to 5 mol/L in the range of −1 to 3 in the presence of a chelating agent.  
     
     
         14 . The aggregate comprising ultrafine particles of a rutile-type titanium oxide according to  claim 13 , wherein the chelating agent is one or more selected from hydroxycarboxylic acids, diketones, keto esters and dicarboxylic acids.  
     
     
         15 . The aggregate comprising ultrafine particles of a rutile-type titanium oxide according to  claim 14 , wherein the hydroxycarboxylic acid is glycolic acid, lactic acid, citric acid, tartaric acid or salts thereof.  
     
     
         16 . The aggregate comprising ultrafine particles of a rutile-type titanium oxide according to  claim 14 , wherein the diketone is acetylacetone or salts thereof.  
     
     
         17 . The aggregate comprising ultrafine particles of a rutile-type titanium oxide according to  claim 13 , wherein the chelating agent is added in a mole ratio of the chelating agent to titanium of 0.0005 to 0.05.  
     
     
         18 . A photocatalyst containing the aggregate according to  claim 13 .  
     
     
         19 . The photocatalyst according to  claim 18 , which is calcined at 100 to 800 degree centigrade.  
     
     
         20 . A method for preparing an aggregate comprising ultrafine particles of a rutile-type titanium oxide, comprising maintaining the pH of an aqueous solution of a titanium compound having a Ti concentration of 0.07 to 5 mol/L in the range of −1 to 3 in the presence of a chelating agent.  
     
     
         21 . The method for preparing an aggregate comprising ultrafine particles of a rutile-type titanium oxide according to  claim 20 , wherein the chelating agent is one or more selected from hydroxycarboxylic acids, diketones, keto esters and dicarboxylic acids.  
     
     
         22 . The method for preparing an aggregate comprising ultrafine particles of a rutile-type titanium oxide according to  claim 21 , wherein the hydroxycarboxylic acid is glycolic acid, lactic acid, citric acid, tartaric acid or salts thereof.  
     
     
         23 . The method according to  claim 21 , wherein the diketone is acetylacetone or salts thereof.  
     
     
         24 . The method according to  claim 20 , comprising adding the chelating agent in a mole ratio of the chelating agent to titanium of 0.0005 to 0.05.  
     
     
         25 . A photocatalyst according to  claim 6 , which is for decomposing an organic compound.  
     
     
         26 . A method for decomposing an organic compound using the photocatalyst according to  claim 6 .  
     
     
         27 . The photocatalyst according to  claim 25 , wherein the organic compound is aldehyde, toluene or an organic dye.  
     
     
         28 . The decomposing method according to  claim 26 , wherein the organic compound is aldehyde, toluene or an organic dye.