Abstract: An object of the present invention is to provide a method for producing metal oxide particles, in which metal oxide particles with high photocatalytic activity is produced, and a production apparatus therefor. The above object can be achieved by using a method for producing metal oxide particles, which includes subjecting a reaction gas containing metal chloride and an oxidizing gas containing no metal chloride in a reaction tube (11) to preheating, and then subjecting a combined gas composed of the reaction gas and the oxidizing gas to main heating in a main heating region (A) apart from the downstream side of the junction (5b), wherein the time until the combined gas from the junction (5b) arrives at the upstream end (A1) of the main heating region (A) is adjusted to be less than 25 milliseconds.

Abstract: There is provided a method and an apparatus for producing metal oxide particles, which produce metal oxide particles having a high photocatalytic activity with high yield.

Abstract: Provided is a method for producing decahedral titanium oxide particles, wherein the decahedral titanium oxide particles are produced by allowing a reaction gas containing titanium tetrachloride to flow into a reaction pipe having a partial double-pipe structure in which a hollow internal cylinder is inserted into an upstream portion of a hollow external cylinder, the method comprising: performing a preheating on the reaction gas containing titanium tetrachloride and a barrier gas not containing metal chlorides in a region on the upstream side of a downstream end of the hollow internal cylinder, while allowing the reaction gas to flow into the hollow internal cylinder and the barrier gas to flow between the hollow internal cylinder and the hollow external cylinder; and performing a main heating on the reaction gas in a downstream region apart from the downstream end of the hollow internal cylinder to thermally decompose the titanium tetrachloride.

Abstract: There is provided a method and an apparatus for producing metal oxide particles, which produce metal oxide particles having a high photocatalytic activity with high yield.

Abstract: An object of the present invention is to provide a method for producing metal oxide particles, in which metal oxide particles with high photocatalytic activity is produced, and a production apparatus therefor. The above object can be achieved by using a method for producing metal oxide particles, which includes subjecting a reaction gas containing metal chloride and an oxidizing gas containing no metal chloride in a reaction tube (11) to preheating, and then subjecting a combined gas composed of the reaction gas and the oxidizing gas to main heating in a main heating region (A) apart from the downstream side of the junction (5b), wherein the time until the combined gas from the junction (5b) arrives at the upstream end (A1) of the main heating region (A) is adjusted to be less than 25 milliseconds.

Abstract: Titanium oxide particles having a particle having a decahedral box-shape and a particle size in a range of from 1 nm to 100 nm can be selectively and efficiently produced by carrying out a method in which in a case of oxidizing titanium tetrachloride in vapor at high temperatures, it is rapidly heated and cooled, and a method, in which water vapor is used as an oxidizing gas, in combination under certain conditions.

Abstract: The invention relates to nanostructure and its manufacturing method. In the manufacturing method of a nanostructure, first anisotropic crystalline particles, connectors having end to be connected to a specific crystal face of each of said crystalline particles, and second particles to be connected to the other end of each of said connectors are prepared. First ends of the connectors are connected to specific crystal faces of the first crystalline particles, and simultaneously or before or after the connection, the second ends of the connectors are connected to the second particles. A nanostructure formed by this method has a three-dimensional structure which does not have a closest packing structure.

Abstract: To provide a tungsten oxide photocatalyst which shows a high photocatalytic activity by irradiating with visible light even under the environment where ultraviolet light is not irradiated, the tungsten oxide photocatalyst has tungsten oxide particles and Pt particles having a primary particle size of 3 to 20 nm supported on the surface of the tungsten oxide particles in an amount of 0.03 to 5 parts by weight based on 100 parts by weight of the tungsten oxide particles.

Abstract: Titanium oxide particles having a particle having a decahedral box-shape and a particle size in a range of from 1 nm to 100 nm can be selectively and efficiently produced by carrying out a method in which in a case of oxidizing titanium tetrachloride in vapor at high temperatures, it is rapidly heated and cooled, and a method, in which water vapor is used as an oxidizing gas, in combination under certain conditions.

Abstract: According to the present invention, two hydroxyl groups can be introduced into the 1-position and the 4-position of the benzene ring of an aromatic compound highly efficiently and highly selectively by a one step process to give the corresponding aromatic hydroxide. The present invention provides a production method of an aromatic hydroxide represented by the formula (2) wherein R1, R2, R3, and, R4 are each independently a hydrogen atom or an alkyl group having a carbon atom number of 1-20, and R1, R2 and/or R3 and R4 are optionally bonded to each other to form a ring, which comprises irradiating light to a photoelectrode comprised of metal oxide while applying a given potential in the presence of an aromatic compound represented by the formula (1) wherein R1, R2, R3, and R4 are as defined above.

Abstract: Provided is a method for producing decahedral titanium oxide particles, wherein the decahedral titanium oxide particles are produced by allowing a reaction gas containing titanium tetrachloride to flow into a reaction pipe having a partial double-pipe structure in which a hollow internal cylinder is inserted into an upstream portion of a hollow external cylinder, the method comprising: performing a preheating on the reaction gas containing titanium tetrachloride and a barrier gas not containing metal chlorides in a region on the upstream side of a downstream end of the hollow internal cylinder, while allowing the reaction gas to flow into the hollow internal cylinder and the barrier gas to flow between the hollow internal cylinder and the hollow external cylinder; and performing a main heating on the reaction gas in a downstream region apart from the downstream end of the hollow internal cylinder to thermally decompose the titanium tetrachloride.

Abstract: According to the present invention, two hydroxyl groups can be introduced into the 1-position and the 4-position of the benzene ring of an aromatic compound highly efficiently and highly selectively by a one step process to give the corresponding aromatic hydroxide. The present invention provides a production method of an aromatic hydroxide represented by the formula (2) wherein R1, R2, R3, and, R4 are each independently a hydrogen atom or an alkyl group having a carbon atom number of 1-20, and R1, R2 and/or R3 and R4 are optionally bonded to each other to form a ring, which comprises irradiating light to a photoelectrode comprised of metal oxide while applying a given potential in the presence of an aromatic compound represented by the formula (1) wherein R1, R2, R3, and R4 are as defined above.

Abstract: The present invention provides semiconductor nanoparticles which emit light at room temperature and include a sulfide or oxide containing zinc, a Group 11 element in the periodic table, and a Group 13 element in the periodic table as a main component or a sulfide or oxide containing a Group 11 element in the periodic table and a Group 13 element in the periodic table as a main component. For example, the semiconductor nanoparticles are represented by Zn(1-2x)InxAgxS (O<x?0.5).

Abstract: The invention relates to nanostructure and its manufacturing method. In the manufacturing method of a nanostructure, first anisotropic crystalline particles, connectors having an end to be connected to a specific crystal face of each of said crystalline particles, and second particles to be connected to the other end of each of said connectors are prepared. First ends of the connectors are connected to specific crystal faces of the first crystalline particles, and simultaneously or before or after the connection, the second ends of the connectors are connected to the second particles. A nanostructure formed by this method has a three-dimensional structure which does not have a closest packing structure.

Abstract: To provide a tungsten oxide photocatalyst which shows a high photocatalytic activity by irradiating with visible light even under the environment where ultraviolet light is not irradiated, the tungsten oxide photocatalyst has tungsten oxide particles and Pt particles having a primary particle size of 3 to 20 nm supported on the surface of the tungsten oxide particles in an amount of 0.03 to 5 parts by weight based on 100 parts by weight of the tungsten oxide particles.

Abstract: A core-shell structure comprises a core (2) comprising nanoparticles and a shell (4) coating the core (2), and its void space (3) formed by the core (2) and the shell (4) is controlled. A method of preparing the core-shell structure comprises: forming particles comprising a photoetchable semiconductor, metal or polymer and coating the particles with a shell (4) comprising a non-photoetchable semiconductor, metal or polymer, to form a core-shell structure (5); and irradiating the core-shell structure with a light having a controlled wavelength in the photoetching solution to form an adjustable void space inside a shell (3) within the core-shell structure by the size-selective photoetching method. The core-shell structure allows the preparation of a catalyst exhibiting an extremely high efficiency, and can be used as a precursor for preparing a nanomaterial required for a nanodevice.

Abstract: The invention relates to nanostructure and its manufacturing method. In the manufacturing method of a nanostructure, first anisotropic crystalline particles, connectors having end to be connected to a specific crystal face of each of said crystalline particles, and second particles to be connected to the other end of each of said connectors are prepared. First ends of the connectors are connected to specific crystal faces of the first crystalline particles, and simultaneously or before or after the connection, the second ends of the connectors are connected to the second particles. A nanostructure formed by this method has a three-dimensional structure which does not have a closest packing structure.

Abstract: A core-shell structure comprises a core (2) comprising nanoparticles and a shell (4) coating the core (2), and its void space (3) formed by the core (2) and the shell (4) is controlled. A method of preparing the core-shell structure comprises: forming particles comprising a photoetchable semiconductor, metal or polymer and coating the particles with a shell (4) comprising a non-photoetchable semiconductor, metal or polymer, to form a core-shell structure (5); and irradiating the core-shell structure with a light having a controlled wavelength in the photoetching solution to form an adjustable void space inside a shell (3) within the core-shell structure by the size-selective photoetching method. The core-shell structure allows the preparation of a catalyst exhibiting an extremely high efficiency, and can be used as a precursor for preparing a nanomaterial required for a nanodevice.