Abstract: The present invention provides a porous coordination polymer, wherein the porous coordination polymer is formed of unit lattices; each of the unit lattices has a shape of a cube having eight vertexes and twelve sides; each of the vertexes of the unit lattices consists of a Zn4O cluster; each of the sides of the unit lattices consists of a ?OOC—C?C—COO? group. At least a part of the unit lattices contains at least one hydrogen molecule only, or the inside of at least a part of the unit lattices is empty. The present invention provides a novel porous coordination polymer, especially, a porous coordination polymer suitable for separating hydrogen molecules from a gaseous mixture of the hydrogen molecules and impurity molecules (e.g., nitrogen molecules, oxygen molecules, or carbon dioxide molecules).

Abstract: In a hydrogen producing device, an electrolyte flow path between a plurality of hydrogen producing cells is disposed in a hydrogen production side and in an oxygen production side, separately. Further, an electrolyte flow path is formed through which the electrolyte flows downward from the top between the plurality of hydrogen producing cells, and on the other hand the electrolyte flows upward from the bottom within each hydrogen producing cell. Moreover, a contact point with a produced gas or an atmosphere is provided in a pathway of the electrolyte flow path.

Abstract: The present invention provides a photoelectrode 100 includes a first conductor 101 as a substrate; a second conductor 103 which includes a plurality of pillar structures 102 disposed on the first conductor 101, and is transparent; and a photocatalyst layer 104 including a visible-light photocatalyst and disposed on the surfaces of the pillar structures 102. The photoelectrode according to the present invention is capable of effectively utilizing energy of light for an intended reaction such as a water decomposition reaction.

Abstract: The present invention provides a photoelectrode capable of effectively utilizing energy of light for an intended reaction such as a water decomposition reaction. The present invention provides a photoelectrode 100 includes a first conductor 101 as a substrate; a second conductor 102 which is disposed on first conductor 101, has a porous structure including a three-dimensionally continuous skeleton 102a and pores 102b formed by the skeleton 102a, and is transparent; and a visible-light photocatalyst 103 disposed in the pores of the second conductor 102.

Abstract: Provided is a semiconductor photoelectrode comprising a first conductive layer; a first n-type semiconductor layer disposed on the first conductive layer; and a second conductive layer covering the first n-type semiconductor layer. The first n-type semiconductor layer has a first n-type surface region and a second n-type surface region. The first n-type surface region is in contact with the first conductive layer. The second n-type surface region is in contact with the second conductive layer. The first n-type semiconductor layer is formed of at least one selected from the group consisting of a nitride semiconductor and an oxynitride semiconductor. The second conductive layer is light-transmissive. The second conductive layer is formed of a p-type oxide conductor.

Abstract: A semiconductor material of the present invention is a semiconductor material including an oxynitride containing at least one element selected from the Group 4 elements and Group 5 elements. In the oxynitride, part of at least one selected from oxygen and nitrogen is substituted with carbon. Nb is preferable as the Group 5 element.

Abstract: To provide a method for growing a niobium oxynitride having small carrier density, the present invention is a method for growing a niobium oxynitride layer, the method comprising: (a) growing a first niobium oxynitride film on a crystalline titanium oxide substrate, while a temperature of the crystalline titanium oxide substrate is maintained at not less than 600 Celsius degrees and not more than 750 Celsius degrees; and (b) growing a second nitride oxynitride film on the first niobium oxynitride film, while the temperature of the crystalline titanium oxide substrate is maintained at not less than 350 Celsius degrees, after the step (a), wherein the niobium oxynitride layer comprises the first niobium oxynitride film and the second niobium oxynitride film.

Abstract: A photoelectrode (100) of the present invention includes a conductive layer (12) and a photocatalytic layer (13) provided on the conductive layer (12). The conductive layer (12) is made of a metal nitride. The photocatalytic layer (13) is made of at least one selected from the group consisting of a nitride semiconductor and an oxynitride semiconductor. When the photocatalytic layer (13) is made of a n-type semiconductor, the energy difference between the vacuum level and the Fermi level of the conductive layer (12) is smaller than the energy difference between the vacuum level and the Fermi level of the photocatalytic layer (13). When the photocatalytic layer (13) is made of a p-type semiconductor, the energy difference between the vacuum level and the Fermi level of the conductive layer (12) is larger than the energy difference between the vacuum level and the Fermi level of the photocatalytic layer (13).

Abstract: A hydrogen producing cell of the present invention is provided with an electrolyte supply hole, an electrolyte discharge hole, a first hydrogen circulation hole and a second hydrogen circulation hole respectively penetrating a housing. In disposing the hydrogen producing cell, the electrolyte supply hole is arranged on a vertically upper side than the electrolyte discharge hole, the first hydrogen circulation hole is arranged on a vertically upper side than the electrolyte supply hole, and the second hydrogen circulation hole is arranged on a vertically upper side than the electrolyte discharge hole. By this configuration, it is possible to considerably reduce the length of a pipe and the number of manifolds concerning the electrolyte and hydrogen, and to link the hydrogen producing cells with one another simply and rationally.

Abstract: The present invention provides a method for fabricating a single-crystalline niobium oxynitride film suitable for a hydrogen generation device. The present invention provides a method for fabricating a single-crystalline niobium oxynitride film formed of a niobium oxynitride represented by the chemical formula NbON; the method comprising: (a) epitaxially growing the single-crystalline niobium oxynitride film on one substrate selected from the group consisting of a yttria-stabilized zirconia substrate, a titanium oxide substrate, and a yttrium-aluminum complex oxide substrate.

Abstract: The NbON film of the present invention is a NbON film in which a photocurrent is generated by light irradiation. The NbON film of the present invention is desirably a single-phase film. The hydrogen generation device (600) of the present invention includes: an optical semiconductor electrode (620) including a conductor (621) and the NbON film (622) of the present invention disposed on the conductor (621); a counter electrode (630) connected electrically to the conductor (621); a water-containing electrolyte (640) disposed in contact with a surface of the NbON film (622) and a surface of the counter electrode (630); and a container (610) containing the optical semiconductor electrode (620), the counter electrode (630), and the electrolyte (640). In this device, hydrogen is generated by irradiating the NbON film (622) with light.

Abstract: The present invention provides a method for adsorbing carbon dioxide onto porous metal-organic framework materials, a method for cooling porous metal-organic framework materials, a method for obtaining aldehyde using porous metal-organic framework materials and a method for warming porous metal-organic framework materials. In each method, porous metal-organic framework materials are used while an electric field or an electromagnetic field is applied to the porous metal-organic framework materials, or while a magnetic field or an electromagnetic field is applied to the porous metal-organic framework materials. If an electric field is applied, at least one organic compound included in the porous metal-organic framework materials is a polar compound. Instead, if a magnetic field is applied, at least one metal included in the porous metal-organic framework materials has an unpaired electron.

Abstract: Provided is a method for generating hydrogen. The method comprising (a) preparing a hydrogen generation device comprising a container, a photo-semiconductor electrode comprising a substrate, a light-blocking first conductive layer, and a first semiconductor photocatalyst layer, a counter electrode, a conductive wire for electrically connecting the first conductive layer to the counter electrode, and a liquid stored in the container, and (b) irradiating the first semiconductor photocatalyst layer with light to generate hydrogen on the counter electrode. The first conductive layer is interposed between the substrate and the first semiconductor photocatalyst layer. At least a part of the first semiconductor photocatalyst layer is in contact with the liquid. At least a part of the counter electrode is in contact with the liquid. The liquid is selected from the group consisting of an electrolyte aqueous solution and water. The substrate is formed of a resin.

Abstract: The present invention provides a method for generating hydrogen by water splitting at a higher hydrogen generation efficiency. In the present method, used is a photoelectrochemical cell comprising a container, a liquid stored in the container, a semiconductor electrode contained in the container, and a counter electrode contained in the container. The semiconductor electrode comprises a first semiconductor layer, a light-transmissive conductor layer; and a second semiconductor layer.

Abstract: The present invention provides a fuel cell comprising a cathode, an electrolyte membrane, and an anode. The electrolyte membrane is sandwiched between the cathode and the anode. The cathode is formed of a first proton conductor represented by the following chemical formula Aa(BbMm)O3-x (where A represents a divalent metal, B represents a tetravalent metal, M represents a trivalent metal, 2(3?x)=2a+4b+3m, b+m=1, and x=(3?2a?b)/2) and a mixed ionic electronic conductor. The electrolyte membrane is formed of a second proton conductor represented by the following chemical formula A?a?(B?b?M?m?)O3-x? (where A? represents a divalent metal, B? represents a tetravalent metal, M? represents a trivalent metal, 2(3?x?)=2a?+4b?+3m?, b?+m?=1, and x?=(3?2a??b?)/2). The following mathematical formula m?m? is satisfied. The electric power generation efficiency is improved.

Abstract: A photoelectrochemical cell (100) includes: a semiconductor electrode (120) including a conductor (121) and semiconductor layers (122, 123) disposed on the conductor (121); a counter electrode (130) connected electrically to the conductor (121); an electrolyte (140) in contact with surfaces of the semiconductor layer (123) and the counter electrode (130); and a container (110) accommodating the semiconductor electrode (120), the counter electrode (130) and the electrolyte (140). A band edge level ECS of a conduction band, a band edge level EVS of a valence band, and a Fermi level EFS in a surface near-field region of the semiconductor layer, and a band edge level ECJ of a conduction band, a band edge level EVJ of a valence band, and a Fermi level EFJ in a junction plane near-field region of the semiconductor layer with the conductor satisfy, relative to a vacuum level, ECS?EFS>ECJ?EFJ, EFS?EVS<EFJ?EVJ, ECJ>?4.44 eV, and EVS<?5.67 eV.

Abstract: A photosemiconductor electrode (400) of the present invention includes a conductor (410) and a photosemiconductor layer (first semiconductor layer) (420) provided on the conductor (410). The photosemiconductor layer (420) includes a photosemiconductor (e.g., a photosemiconductor film (421)) and an oxide containing iridium element (e.g., iridium oxide (422)). The Fermi level of the oxide containing iridium element is more negative than the Fermi level of the photosemiconductor and is more negative than ?4.44 eV, with respect to the vacuum level.

Abstract: The present invention is a niobium nitride which has a composition represented by the composition formula Nb3N5 and in which a constituent element Nb has a valence of substantially +5. The method for producing the niobium nitride of the present invention includes the step of nitriding an organic niobium compound by reacting the organic niobium compound with a nitrogen compound gas.

Abstract: The present invention is a niobium nitride which has a composition represented by the composition formula Nb3N5 and in which a constituent element Nb has a valence of substantially +5. The method for producing the niobium nitride of the present invention includes the step of nitriding an organic niobium compound by reacting the organic niobium compound with a nitrogen compound gas.

Abstract: The present invention provides a photoelectrochemical cell. The photoelectrochemical cell comprises a semiconductor photoelectrode which functions as a cathode electrode; a counter electrode which functions as an anode electrode; an electrolyte aqueous solution which is in contact with surfaces of the semiconductor photoelectrode and the counter electrode; and a container containing the semiconductor photoelectrode, the counter electrode, and the electrolyte aqueous solution. The semiconductor photoelectrode includes: a first conductive layer; an n-type semiconductor layer disposed on the first conductive layer; and a second conductive layer which completely covers a surface of the n-type semiconductor layer. The counter electrode is electrically connected to the first conductive layer. The second conductive layer is light-transmissive. The second conductive layer functions as a light incident surface.