# US 8,148,289 B2 · Titanium oxide photocatalyst and method for producing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,148,289 B2 - Document ID: US8148289B2 - Status: Granted - Kind: B2 - Application number: 12/596,293 - Filed: 2008-04-18 - Published: 2010-05-06 - Granted: 2012-04-03 - Earliest claimed: 2007-04-18 - Assignees: Panasonic Corporation; Sakai Chemical Industry Co., Ltd. - Inventors: Noboru Taniguchi; Shuzo Tokumitsu; Tomohiro Kuroha; Kenichi Tokuhiro; Akio Nakashima; Keita Kobayashi; Shinji Nakahara - Web page: https://patentgrep.com/patent/US8148289B2 ## CPC - A61L 9/18: Radiation (A61L9/22 takes precedence) - B01J 21/063: {Titanium; Oxides or hydroxides thereof} - B01J 27/135: with titanium, zirconium, hafnium, germanium, tin or lead - B01J 35/39: Photocatalytic properties - B01J 37/26: Fluorinating - C01G 23/00: Compounds of titanium {(preparation of Ti-compounds from ores or scraps C22B34/12)} - C01G 23/047: Titanium dioxide - B01J 35/615: {100-500 m2/g} - C01P 2002/54: one element only - C01P 2006/12: Surface area - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20) - C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS ## Abstract A titanium oxide photocatalyst that is capable of improving a decomposition rate, and a method for producing the same are provided. The titanium oxide photocatalyst of the present invention is a titanium oxide photocatalyst containing at least an anatase-type titanium oxide and fluorine, wherein a content of the fluorine is 2.5 wt % to 3.5 wt %, and 90 wt % or more of the fluorine is chemically bonded to the anatase-type titanium oxide. ## Claims ### Claim 1 A method for producing a titanium oxide photocatalyst containing at least an anatase-type titanium oxide and fluorine, the method comprising the steps of: mixing a fluorine compound and an aqueous dispersion solution of an anatase-type titanium oxide that absorbs n-butylamine in an amount of 8 μmol/g or less, and when a pH of the mixed solution exceeds 3, adjusting the pH at 3 or less with an acid, whereby the titanium oxide and the fluorine compound are caused to react with each other in the mixed solution; and washing a reaction product obtained by the reaction, whereby a titanium oxide photocatalyst is obtained that contains at least the anatase-type titanium oxide and the fluorine, wherein a content of the fluorine is 2.5 wt % to 3.5 wt %, and, of an entirety of the fluorine, a proportion of fluorine chemically bonded to the anatase-type titanium oxide is 90 wt % or more. ### Claim 2 (depends on 1) The method for producing a titanium oxide photocatalyst according to claim 1, wherein the content of sodium in the anatase-type titanium oxide in the aqueous dispersion solution is 1000 wt ppm or less. ### Claim 3 (depends on 2) The method for producing a titanium oxide photocatalyst according to claim 2, wherein the washing step is a step of washing the reaction product with water and the reaction product is washed until an electric conductivity of water collected after the washing becomes 1 mS/cm or less. ### Claim 4 (depends on 1) The method for producing a titanium oxide photocatalyst according to claim 1, wherein the washing step is a step of washing the reaction product with water and the reaction product is washed until an electric conductivity of water collected after the washing becomes 1 mS/cm or less. ### Claim 5 A method for producing a titanium oxide photocatalyst containing at least an anatase-type titanium oxide and fluorine, the method comprising the steps of: adjusting a pH of an aqueous dispersion solution of a titanium oxide with an alkaline solution until the pH thereof becomes in a range of 7.5 to 9.5, and thereafter filtering the solution; re-dispersing a filtration residue obtained by the filtration into water; obtaining a suspension by adding a fluorine compound to the re-dispersion solution obtained by the re-dispersion, and thereafter adjusting a pH of the suspension with an acid until the pH thereof becomes 3 or less, whereby the titanium oxide and the fluorine compound are caused to react with each other; and washing a reaction product obtained by the reaction, whereby a titanium oxide photocatalyst is obtained that contains at least the anatase-type titanium oxide and the fluorine, wherein a content of the fluorine is 2.5 wt % to 3.5 wt %, and, of an entirety of the fluorine, a proportion of the fluorine chemically bonded to the anatase-type titanium oxide is 90 wt % or more. ### Claim 6 (depends on 5) The method for producing a titanium oxide photocatalyst according to claim 5, wherein the alkaline solution contains at least one selected from the group consisting of ammonia water, an aqueous ammonium carbonate solution, and an aqueous hydrazine solution. ### Claim 7 (depends on 6) The method for producing a titanium oxide photocatalyst according to claim 6, wherein the washing step is a step of washing the reaction product with water and the reaction product is washed until an electric conductivity of water collected after the washing becomes 1 mS/cm or less. ### Claim 8 (depends on 5) The method for producing a titanium oxide photocatalyst according to claim 5, wherein the washing step is a step of washing the reaction product with water and the reaction product is washed until an electric conductivity of water collected after the washing becomes 1 mS/cm or less.