Abstract: The present invention is to provide a photocatalyst electrode for water decomposition exhibiting a high photocurrent density and having reduced dark current. The photocatalyst electrode for water decomposition of the present invention has a photocatalyst layer and a current collector layer that is formed by a vapor deposition method and is disposed on the photocatalyst layer.

Abstract: A hydrogen generation electrode is used for an artificial photosynthesis module that decomposes an electrolytic aqueous solution into hydrogen and oxygen with light. The hydrogen generation electrode has a conductive layer, an inorganic semiconductor layer that is provided on the conductive layer and has a pn junction, and a functional layer that covers an inorganic semiconductor layer. The steam permeability of the functional layer is 5 g/(m2·day) or less.

Abstract: Provided is an artificial-photosynthesis array configured of artificial-photosynthesis modules which have been arranged in one or more rows and which receive light and decompose a supplied aqueous electrolyte solution to thereby obtain hydrogen gas and oxygen gas. The artificial-photosynthesis modules each includes an electrolytic chamber for hydrogen where hydrogen gas is generated and an electrolytic chamber for oxygen where oxygen gas is generated, the chambers being isolated from each other. The electrolytic chambers for hydrogen and electrolytic chambers for oxygen of the artificial-photosynthesis modules are alternately connected so that the electrolytic chamber for hydrogen of each artificial-photosynthesis module is connected to the electrolytic chamber for oxygen of another module and the electrolytic chamber for oxygen of each artificial-photosynthesis module is connected to the electrolytic chamber for hydrogen of another module.

Abstract: Provided is an artificial-photosynthesis module, which decomposes an aqueous electrolyte solution into hydrogen and oxygen by means of light, including a photoelectric conversion unit that receives light to generate electrical energy; a hydrogen gas generating part that decomposes the aqueous electrolyte solution, using the electrical energy of the photoelectric conversion unit, and generates hydrogen gas; and an oxygen gas generating part that decomposes the aqueous electrolyte solution, using the electrical energy of the photoelectric conversion unit, and generates oxygen gas. The photoelectric conversion unit, the hydrogen gas generating part, and the oxygen gas generating part are electrically connected in series, and the hydrogen gas generating part and the oxygen gas generating part are arranged within an electrolytic chamber to which the aqueous electrolyte solution is supplied. The hydrogen gas generating part has an inorganic semiconductor film having a pn junction.

Abstract: A water electrolysis system decomposes an aqueous electrolyte solution into hydrogen and oxygen using light. The water electrolysis system includes a plurality of photoelectric conversion units that have at least one photoelectric conversion element and receive light to generate electrical energy, and a plurality of electrolyte cells in which hydrogen gas and oxygen gas are generated by electrolyzing the aqueous electrolyte solution using the electrical energy obtained by the photoelectric conversion units. The photoelectric conversion units and the electrolyte cells are electrically connected in series. The electrolyte cells are arranged between the photoelectric conversion units, and the photoelectric conversion units or the electrolyte cells located at respective ends in an arrangement state are electrically connected together.

Abstract: The present invention provides a photocatalyst for water splitting which includes barium niobium oxynitride and exhibits excellent water splitting performance and a production method for the same, and a water splitting photoelectrode. The photocatalyst for water splitting of the present invention is a photocatalyst for water splitting including: an optical semiconductor and a promoter supported by the optical semiconductor, in which the optical semiconductor includes barium niobium oxynitride, and the promoter includes at least one substance selected from a group consisting of cobalt oxides and metallic cobalt.

Abstract: Provided are a photocatalyst having higher activity for hydrogen production through water splitting and a photoelectrode comprising the photocatalyst. The photocatalyst for water splitting of the present invention comprises a Ga selenide, an Ag—Ga selenide, or both thereof.

Abstract: The present invention provides an electrode for water-splitting reaction that is capable of increasing conductive path between a photocatalyst layer and a current collecting layer without inhibiting light absorption by photocatalyst, which comprises: a photocatalyst layer 10; a current collecting layer 30; and a contact layer 20 that contains semiconductor or good conductor and is provided between the photocatalyst layer 10 and the current collecting layer 30, wherein the contact layer 20 is provided along the surface shape of the photocatalyst layer 10 at the current collecting layer 30 side of the photocatalyst layer 10.

Abstract: An amorphous carbon having sulfonate group introduced therein is provided which is characterized in that chemical shifts of a condensed aromatic carbon 6-membered ring and a condensed aromatic carbon 6-membered ring having sulfonate group bonded thereto are detected in a 13C nuclear magnetic resonance spectrum and that at least a diffraction peak of carbon (002) face whose half-value width (2?) is in the range of 5 to 30° is detected in powder X-ray diffractometry, and which exhibits proton conductivity. This sulfonated amorphous carbon is very useful as a proton conductor material or solid acid catalyst because it excels in proton conductivity, acid catalytic activity, thermal stability and chemical stability and can be produced at low cost.

Abstract: Provided are a photocatalyst having higher activity for hydrogen production through water splitting and a photoelectrode comprising the photocatalyst. The photocatalyst for water splitting of the present invention comprises a Ga selenide, an Ag—Ga selenide, or both thereof.

Abstract: The invention provides an organic compound(s) hydrogenation device that allows hydrogen derived from water to be stored essentially without generating hydrogen gas. The organic compound hydrogenation device of the invention comprises an oxidation chamber that holds a water-containing electrolyte, a reduction chamber that holds an organic compound(s) with an unsaturated bond, an electrolyte membrane with ion permeability that separates the electrolyte held in the oxidation chamber from the organic compound(s) held in the reduction chamber, an oxidizing electrode that generates protons from the water held in the oxidation chamber, and a reducing electrode that hydrogenates the organic compound(s) held in the reduction chamber.

Abstract: A solid acid catalyst represented by HTixNbyO5 wherein x is 1.1<x<1.2 and y is 0.9>y>0.8, having a Ti/Nb atomic ratio z of 1<z<1.5, and has been produced by subjecting a cation exchangable lamellar metal oxide composed of polyanion nano-sheets comprising lamellar metal oxide layers of titanium niobate being arranged regularly while sandwiching an alkali metal cation between them to the proton exchange of the alkali metal cation by the use of an inorganic acid or an organic acid prepared into a 0.0001M to 1M solution, and then inserting a cation selected from the group consisting of an organic amine and an organic ammonium between the resulting proton exchanged layers, to thereby delaminate the laminated layers temporarily and prepare an aqueous colloidal solution comprising metal oxide sheets having the organic amine or organic ammonium adsorbed thereon, and then adding an inorganic acid or an organic acid prepared into a 0.

Abstract: Disclosed is a photocatalyst activation system characterized by including (a) a catalyst which includes a photocatalytic material containing cerium oxide, or a catalyst which includes a photocatalytic material containing at least one oxide selected from the group consisting of transition metal oxides other than cerium oxide; (b) a light source which irradiates the catalyst with light; and (c) a heat transfer device which transfers heat to the catalyst. By this photocatalyst activation system, it is possible to widen a usable wavelength range of light, and to enhance the catalytic activity to a large extent.

Abstract: An amorphous carbon having sulfonate group introduced therein is provided which is characterized in that chemical shifts of a condensed aromatic carbon 6-membered ring and a condensed aromatic carbon 6-membered ring having sulfonate group bonded thereto are detected in a 13C nuclear magnetic resonance spectrum and that at least a diffraction peak of carbon (002) face whose half-value width (2?) is in the range of 5 to 30° is detected in powder X-ray diffractometry, and which exhibits proton conductivity. This sulfonated amorphous carbon is very useful as a proton conductor material or solid acid catalyst because it excels in proton conductivity, acid catalytic activity, thermal stability and chemical stability and can be produced at low cost.

Abstract: A composite solid strong acid comprising, a solid acid and a carbon material, wherein said solid acid is obtained by heat treating of polycyclic aromatic hydrocarbons or polycyclic aromatic hydrocarbons to which the carbon material is blended in concentrated sulfuric acid or fuming sulfuric acid, transforming said polycyclic aromatic hydrocarbons to a solid acid which is insoluble in a polar solvent by condensation and sulfonation further compositing with said carbon material.

Abstract: A composite solid strong acid comprising, a solid acid and a carbon material, wherein said solid acid is obtained by heat treating of polycyclic aromatic hydrocarbons or polycyclic aromatic hydrocarbons to which the carbon material is blended in concentrated sulfuric acid or fuming sulfuric acid, transforming said polycyclic aromatic hydrocarbons to a solid acid which is insoluble in a polar solvent by condensation and sulfonation further compositing with said carbon material.

Abstract: A method for preparation for mesoporous oxide comprising a non silica oxide having a hexagonal pore structure periodicity and an average maximum pore length of from 2 nm to 5 nm, characterized by comprising blending 0.003 mol to 0.01 mol of TaCl5, NbCl5 or a mixture thereof and Al isopropoxide comprising 10 g of an aliphatic linear alcohol and 1 g of a template compound to prepare a mixture for forming a sol solution, adding 5 mol to 35 mol (based on the metal compounds) of water or an aqueous inorganic acid solution to the mixture followed by hydrolysis and polycondensation to give a sol solution, transferring the sol into an oxygen containing atmosphere followed by again at 40° C. to 100° C. to form a gel, and then calcinating the gel in an oxygen containing atmosphere at 350° C. to 550° C.; and the mesoporous oxide obtained by the method.

Abstract: A meso porous transition metal oxide comprising one or more transition metal oxides, wherein the metal is selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ru, Cd, In, Sn, Sb, Hf, Ta, W and Re, and the pore wall of the meso pore thereof has a crystalline structure; and a method for preparing the meso porous transition metal oxide, characterized as comprising a step of carrying out a secondary calcination at 600-800° C. for 10 minutes to 10 hours.

Abstract: The present invention is the method for preparation of transition metal oxide having micro-mesoporous structure whose average fine pores size is not less than 1 nm and not more than 2 nm comprising, adding and dissolving transition metal salt which is a precursor of transition metal oxide and/or metal alkoxide in the solution prepared by dissolving polymer surfactant in organic solvent, hydrolyzing said transition metal salt and/or metal alkoxide and preparing sol solution which is polymerized and self organized, then obtaining gel whose organization is stabilized from said sol solution and removing said polymer surfactant by using water of room temperature or water to which alkali metal or alkaline earth metal ion is added.

Abstract: A composite solid strong acid comprising, a solid acid and a carbon material, wherein said solid acid is obtained by heat treating of polycyclic aromatic hydrocarbons or polycyclic aromatic hydrocarbons to which the carbon material is blended in concentrated sulfuric acid or fuming sulfuric acid, transforming said polycyclic aromatic hydrocarbons to a solid acid which is insoluble in a polar solvent by condensation and sulfonation further compositing with said carbon material.