JP5424594B2 - Reaction cell for organic photoresponsive element - Google Patents

Description

  The present invention relates to a reaction chamber for a two-chamber type organic photoresponsive device using an organic photoresponsive device including a p-type organic semiconductor and an n-type organic semiconductor.

  Decomposing water molecules into hydrogen and oxygen using light has attracted much attention as a potential solar energy conversion and storage system. Among them, photocatalysts that can decompose water under visible light irradiation. Development has become a big topic in recent years.

  Further, generating hydrogen without generating carbon dioxide is a necessary technology for building a hydrogen-circulating energy society that can replace the carbon cycle.

  In normal water electrolysis, electricity, which is the driving force, is generated while discharging a large amount of carbon dioxide, which has problems from the viewpoint of energy efficiency, environmental destruction, global warming, etc. .

  In order to solve these problems, attempts have been made to actively use natural energy (for example, light energy). For example, Non-Patent Document 1 reports a water decomposition reaction by an inorganic semiconductor photocatalyst using light energy. However, the photocatalyst is only a few types such as titanium oxide, a composite thereof, and tungsten oxide that can use ultraviolet light or visible light in the near ultraviolet region (Non-patent Document 2).

Under such circumstances, the present inventors have developed an organic photocatalyst including a p-type organic semiconductor and an n-type organic semiconductor as a photocatalyst that can utilize light over the entire visible light region, and using this organic photocatalyst, A water electrolysis method was proposed in which a voltage was applied while irradiating light (see Patent Document 1).
Japanese Patent No. 3995051 Nature, 414, pp. 625-627 (2001) Chem. Commun. , 150 (1992)

  An object of the present invention is to provide a new method for using the organic photocatalyst. Furthermore, another object of the present invention is to provide a method for decomposing organic matter only by light irradiation without applying an external voltage and a method for decomposing water to generate hydrogen or oxygen.

  As a result of intensive studies to achieve the above object, the present inventors have made an organic photoresponsive element in which an organic photocatalyst comprising a specific p-type organic semiconductor and a specific n-type organic semiconductor is coated on an electrode substrate. Is put into two reaction cells, and both organic photoresponsive elements are connected by a conductive wire and irradiated with light, a photocatalytic oxidation reaction occurs in one reaction cell, and a photocatalytic reduction reaction occurs in the other reaction cell. I found out. It has also been found that if this reaction cell is used, the organic matter or water can be decomposed without applying a voltage from the outside. Based on these findings, the present inventor has further developed and completed the present invention.

  That is, the present invention provides the following reaction cell for organic photoresponsive elements.

  Item 1. A reaction cell for an organic photoresponsive element having a two-chamber reaction cell composed of a first chamber and a second chamber, wherein the first chamber has an electrolyte solution containing an electron donor. The first organic photoresponsive element is immersed, and the surface of the electrode base material is coated with a first layer made of an n-type organic semiconductor and a second layer made of a p-type organic semiconductor. The second chamber is formed by immersing the second organic photoresponsive element or the metal electrode in an electrolyte solution containing an electron acceptor, and the second organic photoresponsive element is formed on the surface of the electrode substrate. Further, a first layer made of a p-type organic semiconductor and a second layer made of an n-type organic semiconductor may be coated, and a transition metal catalyst may be further supported on the second layer. The second chamber is an electrode base material of the first organic light responsive element and an electrode base material or metal electrode of the second organic light responsive element. The reaction cell reaction cell each other are connected by a salt bridge with but is connected outside of the reaction cell by a conductive wire.

  Item 2. Item 2. The reaction cell according to Item 1, wherein the electron donor in the first chamber is at least one selected from the group consisting of water, hydroxide ions, organic substances, ferrocyanide ions, and iron (II) ions.

  Item 3. Item 3. The reaction cell according to Item 2, wherein the electron donor in the first chamber is an organic substance.

  Item 4. Item 4. The reaction cell according to Item 3, wherein the organic substance is at least one selected from the group consisting of organic thiols, carboxylic acids, aldehydes, and organic amines.

  Item 5. Any one of Items 1-4, wherein the electron acceptor in the second chamber is at least one selected from the group consisting of water, hydrogen ions, ferricyanide ions, iron (III) ions, peroxodisulfate ions, and oxygen. A reaction cell according to claim 1.

  Item 6. The electron donor in the first chamber is at least one selected from the group consisting of water, hydroxide ions, organic thiols, carboxylic acids, aldehydes, organic amines, ferrocyanide ions, and iron (II) ions. The second chamber includes a second organic photoresponsive element, and the second organic photoresponsive element includes a first layer made of a p-type organic semiconductor and a first layer made of an n-type organic semiconductor on the surface of the electrode substrate. Two layers are coated, and a transition metal catalyst is further supported on the second layer. The electron acceptor is at least one selected from the group consisting of water and hydrogen ions. The chamber and the second chamber are formed by connecting the electrode base material of the first organic light responsive element and the electrode base material of the second organic light responsive element outside the reaction cell by a conductive wire and by reacting the reaction cells by a salt bridge. Any one of the items 1-5 to which is connected The placing of the reaction cell.

  Item 7. The electron donor in the first chamber is at least one selected from the group consisting of water and hydroxide ions, the second chamber includes a metal electrode, and the electron acceptor is ferricyanide. And at least one selected from the group consisting of ions, iron (III) ions, peroxodisulfate ions, and oxygen, wherein the first chamber and the second chamber are an electrode substrate and a metal of the first organic photoresponsive element Item 6. The reaction cell according to any one of Items 1 to 5, wherein the electrode is connected to the outside of the reaction cell by a conductive wire and the reaction cells are connected to each other by a salt bridge.

  Item 8. Item 8. The reaction cell according to any one of Items 1 to 7, wherein the p-type organic semiconductor is at least one selected from the group consisting of phthalocyanine derivatives, naphthalocyanine derivatives, and porphyrin derivatives.

  Item 9. Item 9. The reaction cell according to Item 8, wherein the p-type organic semiconductor is a phthalocyanine derivative.

  Item 10. Any one of Items 1 to 9, wherein the n-type organic semiconductor is at least one selected from the group consisting of fullerenes, carbon nanotubes, a conductive polymer doped with an electron donor, a perylene derivative, and a naphthalene derivative. The described reaction cell.

  Item 11. Item 11. The reaction cell according to Item 10, wherein the n-type organic semiconductor is at least one selected from the group consisting of fullerenes and perylene derivatives.

  Item 12. Item 5. The reaction cell according to Item 3 or 4, wherein the first chamber is irradiated with light without applying voltage to the first chamber and the second chamber, and the organic matter is oxidatively decomposed by light induction.

  Item 13. Item 7. The reaction cell according to Item 6, wherein light is applied to both chambers without applying voltage to the first chamber and the second chamber, and water is decomposed by light induction to generate hydrogen.

  Item 14. Item 8. The reaction cell according to Item 7, wherein light is applied to the first chamber without applying voltage to the first chamber and the second chamber, and oxygen is generated by decomposing water by light induction.

  If the reaction cell for an organic photoresponsive element of the present invention is used, an oxidation reaction and a reduction reaction can be caused in each reaction chamber of the two-chamber type reaction cell, so that the photocatalytic reaction can be completed at different locations. it can.

  By irradiating the reaction cell for an organic photoresponsive element of the present invention with light, the organic matter can be oxidatively decomposed without applying a voltage from the outside. Therefore, a method for oxidatively decomposing organic matter by light induction can be provided. . In addition, by irradiating the reaction cell for an organic light-responsive element of the present invention with light, water can be decomposed without applying a voltage from the outside, so that photoinduced hydrogen or oxygen generation reaction can be provided. it can.

  Hereinafter, the present invention will be described in detail.

  The reaction cell for an organic photoresponsive element of the present invention (hereinafter sometimes simply referred to as “reaction cell”) has a two-chamber reaction cell composed of a first chamber and a second chamber. The second chamber has the following configuration.

(1) The first chamber is formed by immersing the first organic photoresponsive element in an electrolyte solution containing an electron donor, and the first organic photoresponsive element is formed on the surface of the electrode substrate. A first layer made of an n-type organic semiconductor and a second layer made of a p-type organic semiconductor are coated.
(2) The second organic photoresponsive element or metal electrode is immersed in an electrolyte solution containing an electron acceptor, and the second organic photoresponsive element is formed on the surface of the electrode base material by p. A first layer made of a type organic semiconductor and a second layer made of an n type organic semiconductor may be coated, and a transition metal catalyst may be further supported on the second layer.
(3) In the first chamber and the second chamber, the electrode base material of the first organic light responsive element and the electrode base material or metal electrode of the second organic light responsive element are connected outside the reaction cell by a conductive wire. In addition, the reaction cells are connected by a salt bridge.

  By configuring such a two-chamber reaction cell, an oxidation reaction occurs in the first chamber and a reduction reaction occurs in the second chamber. This provides a new type of reaction cell that can complete the photocatalytic reaction at different locations.

  Both the first organic photoresponsive element provided in the first chamber and the second organic photoresponsive element provided in the second chamber are coated with an n-type organic semiconductor and a p-type organic semiconductor on the surface of the electrode substrate. .

Examples of the electrode substrate used in the first organic photoresponsive element and the second organic photoresponsive element include a conductive transparent glass substrate, a metal substrate, and a carbon-based substrate. Specifically, for example, a conductive transparent glass substrate coated with indium-tin oxide (ITO) or the like; a metal substrate such as platinum; a carbon-based substrate such as graphite, diamond, or glassy carbon; The resistance value of the electrode substrate is, for example, 5 to 100 Ω / cm ² , preferably 8 to 20 Ω / cm ² . Various shapes can be adopted as the shape of the electrode base material, but a flat plate shape or a substrate shape having a large electrode surface that increases the efficiency of light irradiation is preferable.

  Examples of the p-type organic semiconductor used in the first organic photoresponsive element and the second organic photoresponsive element include a macrocyclic ligand compound or a metal complex thereof. The macrocyclic ligand compound is a cyclic compound that can be a metal ligand containing an atom having an unpaired electron on the ring, and the metal complex is the macrocyclic ligand and It means a metal complex consisting of metal atoms. As an atom which has an unpaired electron, a nitrogen atom and an oxygen atom are mentioned, for example, A nitrogen atom is preferable. As a metal atom, each metal element of 1-15 group of a periodic table is mentioned, Preferably it is a 4-14 group metal element. In addition, the metal complex may be any metal as long as the metal atom and the macrocyclic ligand compound are 1: 1 (molar ratio) and form a planar four-coordinate complex.

  Specific examples of the macrocyclic ligand compound or the metal complex thereof include phthalocyanine derivatives, naphthalocyanine derivatives, porphyrin derivatives, and the like.

  A phthalocyanine derivative means a compound having a basic phthalocyanine skeleton. Specifically, for example, the following formula (1A) or (1B):

(In the formula, M ¹ represents a metal atom selected from the group consisting of groups 4 to 14 of the periodic table or an atomic group containing the metal atom, and a dotted line represents a coordinate bond)
The phthalocyanine derivative represented by these is mentioned.

Preferably among the Periodic Table 4-14 metals atom represented by M ^1, 7 group (in particular, Mn), Group 8 (Fe, Ru, Os) , 9 group (Co, Rh, Ir), 10 Group (Ni, Pd, Pt), Group 11 (particularly Cu), Group 12 (particularly Zn).

Among the above, the phthalocyanine represented by the formula (1A), or the phthalocyanine derivative in which M ¹ is Co, Pt, Os, Mn, Ir, Fe, Rh, Cu, Zn, Ni, Pd, or Ru in the formula (1B) In particular, metal-free phthalocyanine, zinc phthalocyanine or copper phthalocyanine is preferable from the viewpoint of activity in organic oxidative decomposition, and cobalt phthalocyanine is preferable from the viewpoint of the amount of oxygen generated in water decomposition. These compounds are either commercially available or can be easily produced by those skilled in the art.

  A naphthalocyanine derivative means a compound having a basic skeleton of naphthalocyanine. Specifically, for example, the following formula (2A) or (2B):

(In the formula, M ² represents a metal atom selected from the group consisting of groups 4 to 14 of the periodic table or an atomic group containing the metal atom, and a dotted line represents a coordinate bond)
The naphthalocyanine derivative represented by these is mentioned.

Of the metal atoms in groups 4 to 14 of the periodic table represented by M ² , group 7 (particularly Mn), group 8 (Fe, Ru, Os), group 9 (Co, Rh, Ir), group 10 are preferred. (Ni, Pd, Pt), Group 11 (particularly Cu), Group 12 (particularly Zn).

Among the above, naphthalocyanine represented by the formula (2A), or naphthalocyanine in which M ² is Co, Pt, Os, Mn, Ir, Fe, Rh, Cu, Zn, Ni, Pd, or Ru in the formula (2B) Derivatives are preferred, and metal-free naphthalocyanine, zinc naphthalocyanine or copper naphthalocyanine is particularly preferred from the viewpoint of activity in organic oxidative decomposition, and cobalt naphthalocyanine is preferred from the viewpoint of the amount of oxygen generated in the decomposition of water. These compounds are either commercially available or can be easily produced by those skilled in the art.

  A porphyrin derivative means a compound having a basic skeleton of porphyrin. Specifically, for example, the following formula (3A) or (3B):

(In the formula, R ³ represents a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group, and M ³ represents a metal atom selected from the group consisting of groups 4 to 14 of the periodic table or an atomic group containing the metal atom. The dotted line shows the coordination bond)
The porphyrin derivative represented by these is mentioned.

Here, examples of the alkyl group represented by R ³ include a C _1-20 linear or branched alkyl group, and a C _1-10 alkyl group is preferable. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, n-pentyl, n-hexyl, n-heptyl, n-octyl and the like.

Moreover, as an aryl group shown by said R < ³ >, a monocyclic or bicyclic aryl group is mentioned, Specifically, a phenyl, a naphthyl, etc. are mentioned.

Examples of the heteroaryl group represented by R ³ include pyridyl and pyrazinyl.

Of the metal atoms of groups 4 to 14 of the periodic table represented by M ³ , group 7 (particularly Mn), group 8 (Fe, Ru, Os), group 9 (Co, Rh, Ir), group 10 are preferred. (Ni, Pd, Pt), Group 11 (particularly Cu), Group 12 (particularly Zn).

Among the above, porphyrin represented by the formula (3A), or in the formula (3B), M ³ is Co, Pt, Os, Mn, Ir, Fe, Rh, Cu, Zn, Ni, Pd or Ru, R ³ is A porphyrin derivative which is a phenyl or hydrogen atom is preferred, and metal-free porphyrin, zinc porphyrin or copper porphyrin is particularly preferred from the viewpoint of activity in organic oxidative decomposition, and cobalt porphyrin is preferred from the viewpoint of the amount of oxygen generated in the decomposition of water. These compounds are either commercially available or can be easily produced by those skilled in the art.

Examples of the p-type organic semiconductor used in the first and second organic photoresponsive elements include the macrocyclic ligand compounds described above or metal complexes thereof. Preferably, a phthalocyanine derivative, a naphthalocyanine derivative, or a porphyrin derivative is used. Can be mentioned. More preferably, the compound represented by Formula (1A), (1B), (2A), (2B), (3A), (3B) is mentioned. In particular, as a p-type organic semiconductor used in the first organic photoresponsive element, from the viewpoint of oxidative decomposition activity of organic matter, metal-free phthalocyanine represented by the formula (1A) and M ¹ in the formula (1B) are Zn, A metal complex of phthalocyanine (zinc phthalocyanine and copper phthalocyanine) each represented by Cu is preferable. From the viewpoint of activity against oxygen generation, a metal complex of phthalocyanine (cobalt phthalocyanine) in which M ¹ is represented by Co in formula (1B) is preferable. preferable. The p-type organic semiconductor is available as a commercial product or can be easily manufactured by those skilled in the art.

  Examples of the n-type organic semiconductor used in the first organic photoresponsive element and the second organic photoresponsive element include polycyclic aromatic compounds (which may be partially saturated). A polycyclic aromatic compound is a compound having a structure in which at least two aromatic rings are condensed, or a structure in which a plurality of aromatic rings are bonded via unsaturated bonds (double bonds, triple bonds, etc.). It means the compound etc. which have. In addition to the benzene ring and the like, the aromatic ring includes a heteroaromatic ring such as a pyrrole ring, an imidazole ring, a pyridine ring, and a quinoxaline ring (all of the rings may be partially saturated).

  The polycyclic aromatic compound may have various substituents within a range that does not adversely affect the present invention. Examples of the substituent include an electron withdrawing group, and specific examples include a carbonyl group, a sulfone group, and a sulfoxide group.

Specific examples of the polycyclic aromatic compound include fullerenes such as C ₆₀ , C ₇₀ , C ₇₆ , C ₈₂ , and C ₈₄ ; carbon nanotubes; electron donors (phenylenediamine, tetraaminoethylene, tris (2, 2-bipyridine) ruthenium) -doped conductive polymers (polyimide, polyphenylene vinylene, polyparaphenylene, polypyrrole, etc.); perylene derivatives; naphthalene derivatives. Among these, perylene derivatives, naphthalene derivatives, fullerenes (C _{60 and the} like) are preferably used, and perylene derivatives and fullerenes (C _{60 and the} like) are particularly preferable.

  A perylene derivative means a compound having a basic skeleton of perylene. Specifically, for example, the following formulas (4A) to (4C):

(Wherein R ¹ represents an alkyl group or an aryl group)
The perylene derivative represented by these is mentioned.

  A naphthalene derivative means a compound having a basic skeleton of naphthalene. Specifically, for example, the following formula (5A):

(Wherein R ² represents an alkyl group or an aryl group)
The naphthalene derivative represented by these is mentioned.

Here, examples of the alkyl group represented by R ¹ or R ² include a C _1-20 linear or branched alkyl group, and a C _1-10 alkyl group is preferable. Specific examples include methyl, ethyl, n-propyl, isopropyl, sec-butyl, isobutyl, n-pentyl, n-hexyl, n-heptyl, n-octyl and the like.

Moreover, as an aryl group shown by said R < ¹ > or R < ² >, a monocyclic or bicyclic aryl group is mentioned, Specifically, a phenyl, a naphthyl, etc. are mentioned.

As the n-type organic semiconductor used in the organic photoresponsive element, one having a good pn junction relationship with the p-type organic semiconductor is used. Examples of the n-type organic semiconductor include the above-described polycyclic aromatic compounds (which may be partially saturated), and preferred are perylene derivatives, naphthalene derivatives, and fullerenes. More preferably, the compound represented by Formula (4A), (4B), (4C), (5A) is mentioned. In particular, from the viewpoint of efficient carrier generation, a perylene derivative (3,4,9,10-perylenetetracarboxyl-bisbenzimidazole) or a fullerene (C ₆₀ or the like) represented by the formula (4A) is preferably used. . The n-type organic semiconductor is available as a commercial product or can be easily manufactured by those skilled in the art.

  The first organic light-responsive element in the first chamber is formed by covering the surface of the electrode base material with a first layer made of an n-type organic semiconductor and a second layer made of a p-type organic semiconductor.

  Here, as a method of coating the electrode substrate with the n-type organic semiconductor and the p-type organic semiconductor, a known method can be adopted, for example, a vacuum deposition method, a sputtering method, an electrochemical coating (electrodeposition), A method such as coating may be used from the solution. Among these, with respect to the perylene derivative / phthalocyanine derivative system, the vacuum deposition method is preferable because a uniform coating film can be obtained.

  The first layer of the first organic light-responsive element is a continuous film having a thickness of usually about 10 to 400 nm (preferably about 20 to 300 nm) covering the electrode substrate, and the second layer is the first layer. The coating is usually a continuous film having a thickness of about 10 to 200 nm (preferably about 50 to 100 nm). Regarding the thickness of the organic semiconductor layer, if the layer is too thick, the absorption efficiency of visible light decreases due to its own filter effect. Therefore, the first layer is more preferably about 20 to 300 nm, and the second layer is more preferably about 50 to 100 nm.

  The first organic photoresponsive element is immersed in an electrolyte solution containing an electron donor.

  As the electrolyte solution in the first chamber, an acidic aqueous solution or an alkaline aqueous solution is preferably used.

  The acidic aqueous solution is preferably an aqueous solution containing an acid such as phosphoric acid or sulfuric acid. Particularly preferred is an aqueous phosphoric acid solution. The hydrogen ion concentration in the aqueous solution is usually about 0.1 mM to 0.1M. For example, when an electrode covered with the above fullerenes / phthalocyanine derivative is used, an acid aqueous solution is preferable, and the pH is preferably about 1 to 4.

  The alkaline aqueous solution preferably contains an electrolyte such as phosphate, sulfate, nitrate, carbonate, acetate in an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. Particularly preferred is an aqueous alkali metal hydroxide solution. The hydroxide ion concentration in the aqueous solution is usually about 0.1 mM to 1M. For example, when an electrode covered with a perylene derivative / phthalocyanine derivative is used, an aqueous alkali metal hydroxide solution is preferable, and the pH is preferably about 10 to 14.

This electrolyte solution contains an electron donor. The electron donor is oxidized by the oxidizing power generated on the p-type organic semiconductor under light irradiation. Examples of such an electron donor include water, hydroxide ions, organic substances, ferrocyanide ions ([Fe (CN) ₆ ] ⁴⁺ ), iron (II) ions (Fe ²⁺ ) and the like. These are used individually by 1 type or in mixture of 2 or more types.

  Here, examples of organic substances include organic thiols, carboxylic acids, aldehydes, and organic amines. Organic thiols include 2-mercaptoethanol, thiophenol, and the like. Carboxylic acids include formic acid, acetic acid and the like. Aldehydes include formaldehyde, acetaldehyde and the like. Organic amines include trimethylamine, triethylamine, and the like. These are used individually by 1 type or in mixture of 2 or more types.

  In the second organic photoresponsive element in the second chamber, the surface of the electrode base material is coated with a first layer made of a p-type organic semiconductor and a second layer made of an n-type organic semiconductor. As a method for coating the electrode substrate with the p-type organic semiconductor and the n-type organic semiconductor, the same method as described above can be used. In addition to the first layer made of a p-type organic semiconductor and the second layer made of an n-type organic semiconductor on the surface of the electrode base material, the second organic photoresponsive element further has a transition metal catalyst (for example, , Ru, Pd, Pt, Ir catalyst, etc., preferably Pt or Ru catalyst) may be supported. When a transition metal catalyst is supported on the second layer, a known method such as electrolytic deposition (electrochemical reduction) may be used.

  The first layer of the second organic light-responsive element is formed of a continuous film having a thickness of usually about 10 to 200 nm (preferably about 50 to 100 nm) covering the electrode substrate, and the second layer is the first layer. The coating is usually a continuous film having a thickness of about 10 to 300 nm (preferably about 20 to 200 nm). Regarding the thickness of the organic semiconductor layer, if the layer is too thick, the absorption efficiency of visible light decreases due to its filter effect. Therefore, the first layer is preferably about 50 to 100 nm, and the second layer is more preferably about 20 to 200 nm.

  The second chamber may be provided with a metal electrode instead of the second organic photoresponsive element described above.

  Examples of the metal electrode include known metal electrodes such as noble metal electrodes such as platinum electrodes and gold electrodes.

  The second organic photoresponsive element or the metal electrode is immersed in an electrolyte solution containing an electron acceptor.

  As the electrolyte solution in the second chamber, the same solution as the electrolyte solution in the first chamber can be used, and an acidic aqueous solution or an alkaline aqueous solution is preferably used.

This electrolyte solution contains an electron acceptor. The electron acceptor is reduced by a reducing force generated on the n-type organic semiconductor under light irradiation. As such, for example, water, hydrogen ion, ferricyanide ion ([Fe (CN) ₆ ³⁺ ), iron (III) ion (Fe ³⁺ ), peroxodisulfate ion (S ₂ O ₈ ²⁻ ), oxygen and the like. These are used individually by 1 type or in mixture of 2 or more types.

  The first chamber and the second chamber configured as described above are configured such that the electrode base material of the first organic light responsive element and the electrode base material or metal electrode of the second organic light responsive element are connected to each other by a conducting wire. The reaction cells are connected to each other by a salt bridge.

  Electrons move between the first chamber and the second chamber by the conducting wire, and ions move between the first chamber and the second chamber by the salt bridge.

  When the first chamber of the reaction cell configured as described above is irradiated with light, the surface of the electrode base material is coated with a first layer made of an n-type organic semiconductor and a second layer made of a p-type organic semiconductor. In the first organic photoresponsive element, electron carriers generated under light (particularly visible light) irradiation flow in the n-type organic semiconductor toward the electrode substrate, and hole carriers generated under light irradiation are p-type organic. Since it flows in the opposite direction to the n-type organic semiconductor in the semiconductor, as a result, an oxidation reaction by holes can be caused at the interface between the p-type organic semiconductor and the electrolyte solution.

  Therefore, when water or hydroxide ions are contained as an electron donor in the electrolyte solution in the first chamber, water or hydroxide ions are oxidized by light irradiation. When an electron donor other than water and hydroxide ions (organic substance, ferrocyanide ion or iron (II) ion) is included as the electron donor, the electron donor is oxidized, and particularly an organic substance is included. In some cases, the organic matter is oxidized and oxidative decomposition of the organic matter occurs.

  Thus, in the reaction cell in which the electron donor in the first chamber is an organic substance, the organic substance is induced by light induction, which is characterized by irradiating the first chamber with light without applying a voltage to the first chamber and the second chamber. A method for oxidative degradation is provided.

  Further, when the second chamber of the reaction cell is irradiated with light, the second organic light in which the surface of the electrode base material is coated with the first layer made of a p-type organic semiconductor and the second layer made of an n-type organic semiconductor. In the response element, electron carriers generated under light (particularly visible light) irradiation flow in the opposite direction to the p-type organic semiconductor in the n-type organic semiconductor, and hole carriers generated under light irradiation are p-type organic. It flows in the semiconductor toward the electrode substrate. As a result, it is possible to cause a reduction reaction by electrons at the interface between the n-type organic semiconductor and the electrolyte solution.

  Therefore, when the electrolyte solution in the second chamber contains water or hydrogen ions as an electron acceptor and the transition metal catalyst is supported on the second layer of the second organic photoresponsive element, water or Hydrogen ions are reduced to generate hydrogen. When an electron acceptor other than water and hydrogen ions (ferricyanide ion, iron (III) ion, peroxodisulfate ion or oxygen) is included as an electron acceptor, the electron acceptor is reduced. Become.

  As described above, if the reaction cell for an organic photoresponsive element of the present invention is used, an oxidation reaction and a reduction reaction can be separately caused in a two-chamber reaction cell, so that the photocatalytic reaction can be completed at different locations. Can do.

  A schematic diagram of a preferred embodiment of the reaction cell of the present invention is shown in FIG.

  The reaction cell 1 in FIG. 1 has a two-chamber reaction cell composed of a first chamber 2 and a second chamber 3.

  The first chamber 2 includes a first organic photoresponsive element 4. The first organic light-responsive element 4 is formed by coating the surface of an electrode base 5 with a first layer 6 made of an n-type organic semiconductor and a second layer 7 made of a p-type organic semiconductor.

  As the electrode substrate 5, the same electrode substrate as described above can be used. Among them, a conductive transparent glass substrate is preferably used, and in particular, a conductive transparent glass substrate coated with indium-tin oxide (ITO) or the like is preferably used.

  The surface of the electrode substrate 5 is covered with a first layer 6 made of an n-type organic semiconductor. As the n-type organic semiconductor, the same n-type organic semiconductor as described above can be used. Examples of the n-type organic semiconductor include the above-described polycyclic aromatic compounds (which may be partially saturated), preferably perylene derivatives, naphthalene derivatives, or fullerenes. More preferably, the compound represented by Formula (4A), (4B), (4C), (5A) is mentioned. In particular, from the viewpoint of efficient carrier generation, a perylene derivative (3,4,9,10-perylenetetracarboxyl-bisbenzimidazole) represented by the formula (4A) is preferably used.

  A second layer 7 made of a p-type organic semiconductor is coated on the first layer 6. As the p-type organic semiconductor, the same p-type organic semiconductor as described above can be used. Among them, those having high oxidation activity are used. Examples of the p-type organic semiconductor include the above-described macrocyclic ligand compounds or metal complexes thereof, preferably phthalocyanine derivatives, naphthalocyanine derivatives, and porphyrin derivatives. More preferably, the compound represented by Formula (1A), (1B), (2A), (2B), (3A), (3B) is mentioned. In particular, a metal-free phthalocyanine represented by the formula (1A) is preferable.

  For example, the first organic light-responsive element 4 forms an n-type organic semiconductor layer (first layer) 6 by vacuum-depositing an n-type organic semiconductor on the electrode base material 5, and then forms a vacuum on the p-type organic semiconductor. The p-type organic semiconductor layer (second layer) 7 can be formed by vapor deposition.

  The first layer 6 of the first organic light-responsive element 4 is composed of a continuous film having a thickness of usually about 10 to 400 nm (preferably about 20 to 300 nm) covering the electrode substrate 5, and the second layer 7 is The first layer 6 is usually formed of a continuous film having a thickness of about 10 to 200 nm (preferably about 50 to 100 nm). Regarding the thickness of the organic semiconductor layer, if the layer is too thick, the absorption efficiency of visible light decreases due to its own filter effect. Therefore, the first layer 6 is more preferably about 20 to 300 nm, and the second layer 7 is more preferably about 50 to 100 nm. .

  The first organic photoresponsive element 4 configured as described above is immersed in an electrolyte solution 8 containing an electron donor.

  As the electrolyte solution 8, an acidic aqueous solution or an alkaline aqueous solution is preferably used.

  The acidic aqueous solution is preferably an aqueous solution containing an acid such as phosphoric acid or sulfuric acid. Particularly preferred is an aqueous phosphoric acid solution. The hydrogen ion concentration in the aqueous solution is usually about 0.1 mM to 0.1M. The pH is preferably about 1 to 4.

  The alkaline aqueous solution preferably contains an electrolyte such as phosphate, sulfate, nitrate, carbonate, acetate in an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. Particularly preferred is an aqueous alkali metal hydroxide solution. The hydroxide ion concentration in the aqueous solution is usually about 0.1 mM to 1M. For example, when an electrode covered with a perylene derivative / phthalocyanine derivative is used, an aqueous alkali metal hydroxide solution is preferable, and the pH is preferably about 10 to 14.

The electrolyte solution 8 contains an electron donor. Examples of the electron donor include water, hydroxide ions, organic thiols, carboxylic acids, aldehydes, organic amines, ferrocyanide ions ([Fe (CN) ₆ ] ⁴⁺ ) and iron (II) ions (Fe ²⁺ ). be able to. These are used individually by 1 type or in mixture of 2 or more types. Preferred are organic thiols or ferrocyanide ions ([Fe (CN) ₆ ] ⁴⁺ ), and 2-mercaptoethanol is particularly preferred.

  On the other hand, the second chamber 3 includes a second organic photoresponsive element 9. In the second organic photoresponsive element 9, the surface of the electrode substrate 10 is covered with a first layer 11 made of a p-type organic semiconductor and a second layer 12 made of an n-type organic semiconductor. Further, a transition metal catalyst is supported thereon.

  As the electrode base material 10, the same electrode material as described above can be used. The electrode substrate 10 may be the same as or different from the electrode substrate 5 of the first organic photoresponsive element 4. As the preferable electrode base material 10, a conductive transparent glass base material can be mentioned, and in particular, a conductive transparent glass base material coated with indium-tin oxide (ITO) or the like is preferable.

  The surface of the electrode substrate 10 is covered with a first layer 11 made of a p-type organic semiconductor. As the p-type organic semiconductor, the same p-type organic semiconductor as described above can be used. Examples of the p-type organic semiconductor include the above-described macrocyclic ligand compounds or metal complexes thereof, preferably phthalocyanine derivatives, naphthalocyanine derivatives, and porphyrin derivatives. More preferably, the compound represented by Formula (1A), (1B), (2A), (2B), (3A), (3B) is mentioned. In particular, a metal-free phthalocyanine represented by the formula (1A) is preferable.

On the first layer 11, a second layer 12 made of an n-type organic semiconductor is coated. As the n-type organic semiconductor, the same n-type organic semiconductor as described above can be used. Among them, those capable of generating hydrogen efficiently in the decomposition of water during light irradiation are used. Examples of such an n-type organic semiconductor include the above-mentioned polycyclic aromatic compounds (which may be partially saturated), and preferably a perylene derivative, a naphthalene derivative, or a fullerene. More preferably, fullerenes (C ₆₀ ) are used.

  The second organic photoresponsive element 9 further carries a transition metal catalyst (for example, Ru, Pd, Pt, Ir catalyst, etc., preferably Pt or Ru catalyst) on the second layer 12. The transition metal catalyst supported on the second layer 12 does not need to completely cover the second layer 12 and may be supported in a dispersed manner. For example, the transition metal catalyst is supported on the second layer 12 in a fine particle state with an average particle size of about 5 to 800 nm (preferably about 10 to 100 nm).

For example, the second organic light-responsive element 9 forms a p-type organic semiconductor layer (first layer) 11 by vacuum-depositing a p-type organic semiconductor on the electrode substrate 10, and then vacuums the n-type organic semiconductor thereon. The n-type organic semiconductor layer (second layer) 12 is formed by vapor deposition. Furthermore, as a method for supporting the transition metal catalyst on the second layer 12, a known method such as an electrolytic deposition method (electrochemical reduction) can be employed. For example, with regard to platinum support, a method of supporting platinum under a photocathode condition by adding a platinum salt such as K ₂ PtCl ₄ , K ₂ PtCl ₆ , or H ₂ PtCl ₆ to an aqueous solution containing sulfuric acid, phosphoric acid, or the like. It is done. As a cathode condition to be applied, the applied voltage is preferably about +0.4 to −0.2 V (vs. Ag / AgCl). The hydrogen ion concentration is usually about 1 mM to 10 mM, and the platinum salt concentration is preferably about 0.1 mM to 1 mM.

  The first layer 11 of the second organic light-responsive element 9 is made of a continuous film having a thickness of usually about 10 to 200 nm (preferably about 50 to 100 nm) covering the electrode substrate 10, and the second layer 12 is The first layer 11 is usually formed of a continuous film having a thickness of about 10 to 300 nm (preferably about 20 to 200 nm). Regarding the thickness of the organic semiconductor layer, if the layer is too thick, the absorption efficiency of visible light decreases due to its own filter effect. Therefore, the first layer 11 is more preferably about 50 to 100 nm, and the second layer 12 is more preferably about 20 to 200 nm. .

  The second organic photoresponsive element 9 configured in this way is immersed in the electrolyte solution 13.

  As the electrolyte solution 13, the same one as the electrolyte solution 8 in the first chamber 2 can be used, and an acidic aqueous solution or an alkaline aqueous solution is preferably used. For example, when an electrode covered with a phthalocyanine derivative / fullerene is used, an acidic aqueous solution, particularly a phosphoric acid aqueous solution is preferable, and the pH is preferably about 1 to 3.

  The electrolyte solution 13 contains at least one selected from the group consisting of water and hydrogen ions as an electron acceptor.

  The first chamber 2 and the second chamber 3 are connected to the electrode base material 5 of the first organic light responsive element 4 and the electrode base material 10 of the second organic light responsive element 9 by the lead wire 14 outside the reaction cell. And the reaction cells are connected by a salt bridge 15.

  When the first chamber 2 and the second chamber 3 of the reaction cell 1 are irradiated with light, an oxidation reaction (photooxidation of the electron donor) occurs in the first chamber 2. In the second chamber 3, a reduction reaction of water or hydrogen ions that are electron acceptors occurs, and hydrogen is generated photocatalytically.

  According to this reaction cell 1, it is possible to cause photo-induced hydrogen generation only by irradiation with light without applying an electrochemical bias.

  Therefore, in the present invention, in the reaction cell 1, light is emitted to both chambers without applying voltage to the first chamber 2 and the second chamber 3 to generate hydrogen by decomposing water by light induction. A method is provided.

  A schematic diagram of another preferred embodiment of the reaction cell of the present invention is shown in FIG.

  The reaction cell 21 in FIG. 2 has a two-chamber reaction cell composed of a first chamber 22 and a second chamber 23.

  The first chamber 22 includes a first organic photoresponsive element 24. The first organic light-responsive element 24 is formed by coating the surface of an electrode substrate 25 with a first layer 26 made of an n-type organic semiconductor and a second layer 27 made of a p-type organic semiconductor.

  As the electrode substrate 25, the same electrode substrate as described above can be used. Among them, a conductive transparent glass substrate is preferably used, and in particular, a conductive transparent glass substrate coated with indium-tin oxide (ITO) or the like is preferably used.

  The surface of the electrode substrate 25 is covered with a first layer 26 made of an n-type organic semiconductor. As the n-type organic semiconductor, the same n-type organic semiconductor as described above can be used. Examples of the n-type organic semiconductor include the above-described polycyclic aromatic compounds (which may be partially saturated), preferably perylene derivatives, naphthalene derivatives, or fullerenes. More preferably, the compound represented by Formula (4A), (4B), (4C), (5A) is mentioned. In particular, from the viewpoint of efficient carrier generation, a perylene derivative (3,4,9,10-perylenetetracarboxyl-bisbenzimidazole) represented by the formula (4A) is preferably used.

A second layer 27 made of a p-type organic semiconductor is coated on the first layer 26. As the p-type organic semiconductor, the same p-type organic semiconductor as described above can be used. Among them, a catalyst having high activity is used as an oxygen generation catalyst that can efficiently generate oxygen in the decomposition of water during light irradiation. Examples of the p-type organic semiconductor include the above-described macrocyclic ligand compounds or metal complexes thereof, preferably phthalocyanine derivatives, naphthalocyanine derivatives, and porphyrin derivatives. More preferably, the compound represented by Formula (1A), (1B), (2A), (2B), (3A), (3B) is mentioned. In particular, a metal complex of phthalocyanine (cobalt phthalocyanine) in which M ¹ is represented by Co in the formula (1B) is preferable.

  The first organic photoresponsive element 24 configured in this way is immersed in the electrolyte solution 28.

  As the electrolyte solution 28, the same solution as the electrolyte solution 8 in the first chamber 2 can be used, and an acidic aqueous solution or an alkaline aqueous solution is preferably used. For example, when an electrode covered with a perylene derivative / phthalocyanine derivative is used, an alkaline aqueous solution, particularly an aqueous alkali metal hydroxide solution is preferred, and the pH is preferably about 10 to 12.

  The electrolyte solution 28 contains at least one selected from the group consisting of water and hydroxide ions as an electron donor.

  For example, the first organic light-responsive element 24 forms an n-type organic semiconductor layer (first layer) 26 by vacuum-depositing an n-type organic semiconductor on the electrode base material 25, and then forms a vacuum on the p-type organic semiconductor. The p-type organic semiconductor layer (second layer) 27 is formed by vapor deposition.

  The first layer 26 of the first organic photoresponsive element 24 is formed of a continuous film having a thickness of usually about 10 to 400 nm (preferably about 20 to 300 nm) covering the electrode substrate 25, and the second layer 27 is The first layer 26 is usually formed of a continuous film having a thickness of about 10 to 200 nm (preferably about 50 to 100 nm). Regarding the thickness of the organic semiconductor layer, if the layer is too thick, the absorption efficiency of visible light decreases due to its own filter effect. Therefore, the first layer 26 is more preferably about 20 to 300 nm, and the second layer 27 is more preferably about 50 to 100 nm. .

  The second chamber 23 includes a metal electrode 29.

  As the metal electrode 29, the metal electrode described above can be used. Preferably, a platinum electrode can be used.

  The metal electrode 29 is immersed in an electrolyte solution 30 containing an electron acceptor.

  As the electrolyte solution 30, an acidic aqueous solution or an alkaline aqueous solution described in the electrolyte solution 8 in the first chamber 2 is preferably used. Among them, an alkali metal hydroxide aqueous solution that is an alkaline aqueous solution is preferable, and the pH is preferably about 10 to 12.

The electrolyte solution 30 contains an electron acceptor. Electron acceptors other than water and hydrogen ions, such as ferricyanide ions ([Fe (CN) ₆ ] ³⁺ ), iron (III) ions (Fe ³⁺ ), peroxodisulfate ions (S ₂ O ₈ ^{2 -} ), Oxygen and the like. These are used individually by 1 type or in mixture of 2 or more types. Preferably, ferricyanide ions ([Fe (CN) ₆ ] ³⁺ ) are used.

  Then, the first chamber 22 and the second chamber 23 are reacted by the salt bridge 15 while the electrode base 25 and the metal electrode 29 of the first organic light-responsive element 24 are connected to the outside of the reaction cell by the conducting wire 14. Cells are connected.

  When the first chamber 22 of the reaction cell 21 is irradiated with light, the first chamber 22 undergoes an oxidation reaction of water or hydroxide ions, which are electron donors, to generate oxygen in a photocatalytic manner. In the second chamber 23, a reduction reaction (reduction of electron acceptors other than water and hydrogen ions) occurs.

  According to this reaction cell 21, it is possible to generate light-induced oxygen generation by simply irradiating light without applying an electrochemical bias.

  Therefore, in the present invention, in the reaction cell 21, the light is induced to decompose oxygen by irradiating light to the first chamber 22 without applying voltage to the first chamber 22 and the second chamber 23, and oxygen Is provided.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.

Example 1 (hydrogen generation using a reaction cell equipped with an organic photoresponsive element in both chambers)
(1) As a material of the first organic light-responsive element, 3,4,9,10-perylenetetracarboxyl-bisbenzimidazole (hereinafter referred to as “PTCBI”) which is an n-type semiconductor and no p-type semiconductor Metal phthalocyanine (H ₂ Pc) was used. In the present invention, those purified by sublimation were used.

The first organic photoresponsive element was produced by a vacuum deposition method. First, on an ITO-coated glass substrate (Asahi Glass Co., Ltd., resistance 8 Ωcm ⁻² ; ITO coated glass transmittance 85% or more; indium tin oxide laminate thickness 174 nm), PTCBI is about 300 nm thick, then on PTCBI H ₂ Pc was laminated to a thickness of about 60 nm.

  This first organic photoresponsive element was cut into 1 cm × 1.5 cm. A portion corresponding to 1 cm × 0.5 cm was wiped off with acetone, and a conductive wire was attached using a silver-containing epoxy adhesive (T-700, manufactured by Toyo Ink Co., Ltd.). In order to prevent contact between the silver portion and water, an epoxy adhesive was used to insulate, and the first organic photoresponsive element was obtained.

(2) As materials for the second organic light-responsive element, fullerene (hereinafter referred to as “C ₆₀ ”) which is an n-type organic semiconductor and metal-free phthalocyanine (hereinafter referred to as “H ₂ Pc”) which is a p-type organic semiconductor. Used). In the present invention, those purified by sublimation were used.

The second organic photoresponsive element was produced by a vacuum deposition method. First, a conductive transparent glass substrate coated with indium-tin oxide (ITO) (hereinafter referred to as “ITO-coated glass substrate” or “ITO”) (Asahi Glass Co., Ltd., resistance 8 Ωcm ⁻² ; glass transmittance of 85% or more) H ₂ Pc with a thickness of about 60 nm and then C ₆₀ with a thickness of about 120 nm on the H ₂ Pc. Further, platinum fine particles (hereinafter referred to as “Pt”) were supported on C ₆₀ .

  This second organic photoresponsive element was cut into 1 cm × 1.5 cm. A portion corresponding to 1 cm × 0.5 cm was wiped off with acetone, and a conductive wire was attached using a silver-containing epoxy adhesive (T-700, manufactured by Toyo Ink Co., Ltd.). In order to prevent contact between the silver part and water, an epoxy adhesive was used to insulate to form a second organic photoresponsive element.

  (3) A two-chamber reaction cell was prepared by the following method. The first organic photoresponsive element prepared in (1) above is placed in the first chamber, the second organic photoresponsive element prepared in (2) above is placed in the second chamber, and the first organic photoresponsive element in the first chamber is placed. The two-chamber reaction cell shown in FIG. 3 is formed by connecting the electrode base material of the photoresponsive element and the electrode base material of the second organic photoresponsive element in the second chamber with a conducting wire, and connecting both reaction cells with a salt bridge. Configured.

  Using the above two-chamber reaction cell, first, the conditions of the second chamber (reduction reaction chamber) are fixed, the conditions of the first chamber (oxidation reaction chamber) are changed, and the amount of hydrogen generated in the second chamber is compared. The most effective conditions of the first chamber were examined.

In the second chamber (reduction reaction chamber), an aqueous phosphoric acid solution (pH = 2) was used as an electrolyte solution, and irradiation was performed for 3 hours from the Pt side with a halogen lamp at an irradiation light amount of 380 mWcm ⁻² . The electron acceptor here is water or hydrogen ion.

The first chamber (oxidation reaction chamber) uses a combination of whether or not 2-mercaptoethanol (hereinafter sometimes simply referred to as thiol) is used as an electron donor (whether or not thiol is used) and whether or not light irradiation is performed. went. In addition, the solution at the time of using 2-mercaptoethanol is potassium hydroxide aqueous solution (pH = 11) containing 5 mM 2-mercaptoethanol. In the case of performing light irradiation, irradiation was performed with a halogen lamp from the ITO-coated glass substrate side at an irradiation light amount of 380 mWcm ⁻² for 3 hours. The results are shown in Table 1.

From the results in Table 1, the photo-induced hydrogen generation reaction on ITO / H ₂ Pc / C ₆₀ / Pt is a condition in which light is irradiated from the ITO side to ITO / PTCBI / H ₂ Pc in an aqueous solution containing thiol. Is the most effective.

  Moreover, it turns out that 2-mercaptoethanol (organic substance) which is an electron donor is oxidized and decomposed | disassembled by light irradiation in the 1st chamber.

  Next, by using the two-chamber type reaction cell, the conditions of the first chamber (oxidation reaction chamber) are fixed, the conditions of the second chamber (reduction reaction chamber) are changed, and the amount of hydrogen generated in the second chamber The most effective conditions for the first chamber were examined.

In the first chamber (oxidation reaction chamber), an aqueous potassium hydroxide solution (pH = 11) containing 5 mM 2-mercaptoethanol was used as the electrolyte solution, and irradiation was performed for 3 hours from the ITO side with a halogen lamp at an irradiation light amount of 380 mWcm ⁻² .

Second chamber (reduction reaction chamber) was performed in combination with whether load Pt on C ₆₀ surface as an organic photoresponsive device, whether to perform the light irradiation. The electron acceptor here is also water or hydrogen ion. In addition, when performing light irradiation, it irradiated with the irradiation light quantity of 380 mWcm ^<-2 > for 3 hours from the Pt side with the halogen lamp. The results are shown in Table 2.

The results in Table _2, the _{C 60} surface of the ITO / H 2 Pc _{/ C 60} in the condition carrying Pt, when subjected to light irradiation, efficiently it can be seen that hydrogen is generated.

Furthermore, the amount of hydrogen generated in the second chamber was compared when C ₆₀ was not used as the organic photoresponsive element in the second chamber (reduction reaction chamber).

In the first chamber (oxidation reaction chamber), an aqueous potassium hydroxide solution (pH = 11) containing 5 mM 2-mercaptoethanol was used as the electrolyte solution, and irradiation was performed for 3 hours from the ITO side with a halogen lamp at an irradiation light amount of 380 mWcm ⁻² .

The second chamber (reduction reaction chamber) was performed by combining whether or not Pt is supported on ITO / H ₂ Pc that does not use C ₆₀ as an organic photoresponsive element and whether or not light irradiation is performed. The electron acceptor here is also water or hydrogen ion. In addition, when performing light irradiation, it irradiated with the irradiation light quantity of 380 mWcm ^<-2 > for 3 hours from the Pt side with the halogen lamp. The results are shown in Table 3.

From the results of Table 3, in the case of using an element that is not laminated C ₆₀ onto H 2 _Pc, efficient hydrogen generation in any condition did not occur. This supports that ITO / H ₂ Pc / C ₆₀ / Pt is an effective element for photo-induced hydrogen generation.

Example 2 (Oxygen generation using a reaction cell provided with an organic photoresponsive element and a metal electrode)
(1) As a material for the first organic light-responsive element, 3,4,9,10-perylenetetracarboxyl-bisbenzimidazole (hereinafter referred to as “PTCBI”) which is an n-type semiconductor and cobalt which is a p-type semiconductor Phthalocyanine (CoPc) was used. In the present invention, those purified by sublimation were used.

The first organic photoresponsive element was produced by a vacuum deposition method. First, on an ITO-coated glass substrate (Asahi Glass Co., Ltd., resistance 8 Ωcm ⁻² ; ITO coated glass transmittance 85% or more; indium tin oxide laminate thickness 174 nm), PTCBI is about 160 nm thick, and then on PTCBI. CoPc was laminated to a thickness of about 90 nm.

  This first organic photoresponsive element was cut into 1 cm × 1.5 cm. A portion corresponding to 1 cm × 0.5 cm was wiped off with acetone, and a conductive wire was attached using a silver-containing epoxy adhesive (T-700, manufactured by Toyo Ink Co., Ltd.). In order to prevent contact between the silver portion and water, an epoxy adhesive was used to insulate, and the first organic photoresponsive element was obtained.

  (2) A two-chamber reaction cell was prepared by the following method. The first organic photoresponsive element-coated electrode prepared in (1) above is placed in the first chamber, the platinum wire is put in the second chamber, and the electrode base material of the first organic photoresponsive element in the first chamber and the second A two-chamber reaction cell shown in FIG. 4 was constructed by connecting the metal electrode of the chamber with a conducting wire and connecting both reaction cells with a salt bridge.

  Using the two-chamber type reaction cell, changing the conditions of the first chamber (oxidation reaction chamber) and the second chamber (reduction reaction chamber), and comparing the amount of oxygen generated in the first chamber, the most effective oxygen The occurrence conditions were examined.

Whether or not hexacyanoiron (III) potassium [K ₃ [Fe (CN) ₆ ]] is used as the electron acceptor in the second chamber (reduction reaction chamber) (the presence or absence of K ₃ [Fe (CN) ₆ ]); The first organic photoresponsive element in the first chamber (oxidation reaction chamber) was combined with whether or not to perform light irradiation.

The solution in the case of using [K ₃ [Fe (CN) ₆ ]] in the second chamber (reduction reaction chamber) is a potassium hydroxide solution containing 50 mM K ₃ [Fe (CN) ₆ ] (pH = 11). ). In the first chamber (oxidation reaction chamber), an aqueous potassium hydroxide solution (pH = 11) was used as the electrolyte solution. Here, the electron donor is water or hydroxide ions. In the case of performing light irradiation, irradiation was performed with a halogen lamp from the ITO-coated glass substrate side at an irradiation light amount of 600 mWcm ⁻³ for 3 hours. The results are shown in Table 4.

From the results of Table 4, ITO / PTCBI / CoPc was used as the organic photoresponsive element in the first chamber under light irradiation, and K ₃ [Fe (CN) ₆ ] was used as the electron acceptor in the second chamber. It can be seen that light-induced oxygen generation occurs efficiently under conditions using an aqueous solution.

It is a schematic diagram of preferable embodiment of the reaction cell of this invention. It is a schematic diagram of preferable embodiment of another reaction cell of this invention. 1 is a schematic diagram of a reaction cell relating to Example 1. FIG. 2 is a schematic diagram of a reaction cell relating to Example 2. FIG.

Claims (14)

A reaction cell for an organic photoresponsive element having a two-chamber reaction cell composed of a first chamber and a second chamber,
The first chamber is formed by immersing the first organic photoresponsive element in an electrolyte solution containing an electron donor, and the first organic photoresponsive element is n-type on the surface of the electrode substrate. A first layer made of an organic semiconductor and a second layer made of a p-type organic semiconductor are coated,
The second chamber is formed by immersing the second organic photoresponsive element or the metal electrode in an electrolyte solution containing an electron acceptor, and the second organic photoresponsive element is formed on the surface of the electrode substrate. A first layer made of a p-type organic semiconductor and a second layer made of an n-type organic semiconductor may be coated, and a transition metal catalyst may be further supported on the second layer,
In the first chamber and the second chamber, the electrode base material of the first organic light responsive element and the electrode base material or metal electrode of the second organic light responsive element are connected to each other outside the reaction cell by a conductive wire and reacted. A reaction cell in which cells are connected by a salt bridge.   2. The reaction cell according to claim 1, wherein the electron donor in the first chamber is at least one selected from the group consisting of water, hydroxide ions, organic substances, ferrocyanide ions, and iron (II) ions.   The reaction cell according to claim 2, wherein the electron donor in the first chamber is an organic substance.   The reaction cell according to claim 3, wherein the organic substance is at least one selected from the group consisting of organic thiols, carboxylic acids, aldehydes, and organic amines.   The electron acceptor in the second chamber is at least one selected from the group consisting of water, hydrogen ions, ferricyanide ions, iron (III) ions, peroxodisulfate ions, and oxygen. The reaction cell in any one. The electron donor in the first chamber is at least one selected from the group consisting of water, hydroxide ions, organic thiols, carboxylic acids, aldehydes, organic amines, ferrocyanide ions, and iron (II) ions. ,
The second chamber includes a second organic photoresponsive element, and the second organic photoresponsive element has a first layer made of a p-type organic semiconductor and a second layer made of an n-type organic semiconductor on the surface of the electrode substrate. A layer is coated, and a transition metal catalyst is further supported on the second layer, and the electron acceptor is at least one selected from the group consisting of water and hydrogen ions,
In the first chamber and the second chamber, the electrode base material of the first organic light responsive element and the electrode base material of the second organic light responsive element are connected to each other outside the reaction cell by a conductive wire and reacted by a salt bridge. The reaction cell according to claim 1, wherein the cells are connected to each other. The electron donor in the first chamber is at least one selected from the group consisting of water and hydroxide ions;
The second chamber includes a metal electrode, and the electron acceptor is at least one selected from the group consisting of ferricyanide ions, iron (III) ions, peroxodisulfate ions, and oxygen,
The first chamber and the second chamber are configured such that the electrode base material and the metal electrode of the first organic photoresponsive element are connected to each other outside the reaction cell by a conductive wire and the reaction cells are connected by a salt bridge. The reaction cell in any one of 1-5.   The reaction cell according to any one of claims 1 to 7, wherein the p-type organic semiconductor is at least one selected from the group consisting of a phthalocyanine derivative, a naphthalocyanine derivative, and a porphyrin derivative.   The reaction cell according to claim 8, wherein the p-type organic semiconductor is a phthalocyanine derivative.   The n-type organic semiconductor is at least one selected from the group consisting of fullerenes, carbon nanotubes, conductive polymers doped with electron donors, perylene derivatives, and naphthalene derivatives. A reaction cell according to 1.   The reaction cell according to claim 10, wherein the n-type organic semiconductor is at least one selected from the group consisting of fullerenes and perylene derivatives.   5. The method of oxidatively decomposing organic matter by light induction, wherein the first cell and the second chamber are irradiated with light without applying voltage to the first chamber and the second chamber in the reaction cell according to claim 3 or 4.   7. The reaction cell according to claim 6, wherein light is applied to both chambers without applying voltage to the first chamber and the second chamber, and hydrogen is generated by decomposing water by light induction.   8. The reaction cell according to claim 7, wherein light is applied to the first chamber without applying a voltage to the first chamber and the second chamber, and oxygen is generated by decomposing water by light induction. .

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