# US 7,608,562 B2 · Method and apparatus for producing photocatalyst > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,562 B2 - Document ID: US7608562B2 - Status: Granted - Kind: B2 - Application number: 12/274,462 - Filed: 2008-11-20 - Published: 2009-05-28 - Granted: 2009-10-27 - Earliest claimed: 2001-11-29 - Assignees: Shibaura Mechatronics Corporation - Inventors: Junji Hiraoka; Minoru Takashio; Tetsuya Fukushima; Daisuke Noguchi; Yoshio Kawamata - Web page: https://patentgrep.com/patent/US7608562B2 ## CPC - C23C 14/5853: {Oxidation} - B01J 21/063: {Titanium; Oxides or hydroxides thereof} - B01J 35/39: Photocatalytic properties - B01J 37/347: {Ionic or cathodic spraying; Electric discharge} - C23C 14/083: {of refractory metals or yttrium} - C23C 14/541: {Heating or cooling of the substrates} - H01J 2237/2001: Maintaining constant desired temperature - H01J 2237/2065: Temperature variations - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A method of producing a photocatalyst according to the invention comprises forming an amorphous titanium oxide and heat-treating it in an atmosphere containing oxygen, whereby a photocatalyst having a good photocatalysis can be obtained. In particular, the amorphous titanium oxide is obtained by using the reactive sputtering method and via deposition at a low temperature and at a high film formation rate. This apparatus can be provided with cooling means to allow enhancement of the throughput of the film formation process. ## Claims ### Claim 1 An apparatus for producing a photocatalyst, comprising: deposition means for forming an amorphous titanium oxide on a substrate by a reactive sputtering method using a target comprising titanium and an oxygen gas; heating means for crystallizing at least a portion of the titanium oxide by heating the titanium oxide in an atmosphere comprising oxygen; and deposition means for forming a coating layer of oxide on the titanium oxide. ### Claim 2 (depends on 1) The apparatus for producing a photocatalyst according to claim 1, wherein the amorphous titanium oxide formed by the deposition means does not substantially have crystalline peaks in an X-ray diffraction pattern; and the titanium oxide crystallized by the heating means has crystalline peaks in an X-ray diffraction pattern. ### Claim 3 (depends on 1) The apparatus for producing a photocatalyst according to claim 1, wherein the titanium oxide formed by the deposition means has a composition formula TiOx with its oxygen composition x being substantially equal to 2. ### Claim 4 (depends on 1) The apparatus for producing a photocatalyst according to claim 1, wherein the formation of the amorphous titanium oxide is carried out at a total pressure of an atmosphere during deposition in the reactive sputtering method and at an addition ratio of the oxygen gas contained in the atmosphere such that when a graph with xy-coordinates is plotted, wherein the x-axis represents the pressure in pascal (Pa) and the y-axis presents the addition ratio in percent (%), respectively, and the points with xy-coordinates of (1.0, 30), (3.5, 10), (5.0, 13), (5.0, 30), (3.5, 30), (1.0, 50), and (1.0, 30) in this order are connected, thereby forming a polygon, the total pressure and the addition ratio are defined by the region within and including the boundaries of the polygon. ### Claim 5 (depends on 1) The apparatus for producing a photocatalyst according to claim 1, wherein a partial pressure of the oxygen gas during deposition in the reactive sputtering method is greater than 0.1 pascal and less than 1.7 pascal. ### Claim 6 (depends on 1) The apparatus for producing a photocatalyst according to claim 1, wherein the heating temperature of the crystallization is 300° C. or higher. ### Claim 7 (depends on 1) The apparatus for producing a photocatalyst according to claim 1, wherein the coating layer comprises silicon oxide. ### Claim 8 (depends on 1) The apparatus for producing a photocatalyst according to claim 1, wherein the formation of the coating layer is carried out by a reactive sputtering method using a target containing an element or elements contained in the coating layer and oxygen gas. ### Claim 9 (depends on 8) The apparatus for producing a photocatalyst according to claim 8, further comprising a heating means for heating the substrate before cooling the substrate. ### Claim 10 (depends on 8) The apparatus for producing a photocatalyst according to claim 8, further comprising a deposition means for forming a buffer layer on the substrate before the amorphous titanium oxide is formed. ### Claim 11 (depends on 10) The apparatus for producing a photocatalyst according to claim 10, wherein the buffer layer is made of silicon oxide. ### Claim 12 (depends on 1) The apparatus for producing a photocatalyst according to claim 1, further comprising a cooling means for cooling the substrate before forming the amorphous titanium oxide.