JP5308661B2 - Catalyst electrode for dye-sensitized solar cell and dye-sensitized solar cell including the same - Google Patents

Abstract

A catalytic electrode for a dye sensitized solar cell including a light transmitting semiconductor electrode containing a dye having photosensitizing potency and an electrolyte layer containing redox pair chemical species, the catalytic electrode disposed opposite to the semiconductor electrode with the electrolyte layer interposed therebetween, which catalytic electrode is characterized by having a conductive polymer layer on an electrode base. Further, there is provided a dye sensitized solar cell comprising at least a light transmitting semiconductor electrode containing a dye having photosensitizing potency, an electrolyte layer containing at least redox pair chemical species and a catalytic electrode disposed opposite to the semiconductor electrode with the electrolyte layer interposed therebetween, wherein the catalytic electrode is the above-mentioned catalytic electrode.

Description

  The present invention relates to a catalyst electrode of a dye-sensitized solar cell and a dye-sensitized solar cell including the same.

In recent years, dye-sensitized solar cells in which a sensitizing dye that absorbs a visible light region is supported on a semiconductor layer have been studied. This dye-sensitized solar cell is expected to be put to practical use because of the advantages that it is inexpensive and can be manufactured by a relatively simple process.
In the dye-sensitized solar cell, electrons are injected into the semiconductor electrode from the sensitizing dye excited by absorbing visible light, and current is taken out through the current collector. On the other hand, the oxidized form of the sensitizing dye is reduced and regenerated by a redox pair in the electrolyte. The oxidized redox pair is reduced on the surface of the catalyst electrode placed opposite to the semiconductor electrode, and the cycle goes around.
Known catalyst electrodes conventionally used in dye-sensitized solar cells include those obtained by applying chloroplatinic acid on a substrate and heat-treating it, and platinum catalyst electrodes obtained by depositing platinum. In this catalyst electrode, oxidation-reduction pair in the electrolyte (e.g., I ₃ ^over / I ^-, etc.) an oxidant reduction reaction for reducing the reduction of the (I ₃ ^{- -} The I reduction reaction reduced to) promptly What has the electrode characteristic which can be advanced is calculated | required.

  However, in view of practical use, electrolytes have been studied for higher viscosity and gelation. However, in the dye-sensitized solar cell provided with the platinum catalyst electrode as described above, the electrolyte is increased in viscosity. The diffusion of iodine, which is a redox couple, is the rate-limiting process of the electron transfer reaction in the solar cell, and there is a problem that the solar cell characteristics are deteriorated. For this reason, in order to rapidly proceed the iodine reduction reaction on the surface of the catalyst electrode, it is necessary to increase the surface area by increasing the film thickness and forming irregularities, resulting in an increase in the amount of platinum used or production. There is a problem that the process becomes complicated and the manufacturing cost increases. Furthermore, it is known that platinum dissolves in an organic solvent generally used as an electrolyte in the presence of water or oxygen, and its use has a problem in terms of stability.

Patent Document 1 discloses a solar cell having an inexpensive and simple configuration using a positive electrode (catalyst electrode) made of a nitrogen-containing heterocyclic compound. According to this method, a pn junction is formed by bringing an electrode coated with polyaniline or polypyrrole or the like and an electrode coated with titanium dioxide into close contact, and a solar cell sensitive to sunlight is obtained. It is also said that the photosensitive region can be expanded to the visible light region by doping a sensitizing dye on both electrodes.
However, in the solar cell using this nitrogen-containing heterocyclic compound, a method of transporting carriers through an electrolyte is used while photoexciting the nitrogen-containing heterocyclic compound as a p-type semiconductor. Compared with the catalyst electrode using platinum in the sensitive solar cell, the generated photocurrent was remarkably low, and its practical use was difficult.

Patent Document 2 discloses a dye-sensitized photovoltaic cell using a back electrode (catalyst electrode) formed of a porous layer of a conductive material, that is, a dye-sensitized solar cell. The back electrode in the patent is described as having an increased surface area due to its porosity, resulting in high catalytic efficiency with respect to electron exchange with the electrolyte.
Patent Document 2 exemplifies a conductive organic polymer, that is, a conductive polymer, together with conductive ceramic particles, as a kind of conductive material forming the porous layer. It is described that these conductive particles have catalytic deposition of metal powder, graphite powder, carbon black, and platinum group metals as options, and then are dispersed on the back electrode. That is, the conductive polymer acts as a carrier and can be subjected to a catalyst. Among these, the combination of graphite powder and carbon black has an electrocatalytic action against corrosion resistance and redox couple, and is described as being excellent, and as a reason for having an excellent catalytic action, It is described as being due to the very large surface area of carbon black. Further, it is described that an adhesive is required to agglomerate and fix these powder powders, and that the adhesive can be suitably used by sintering titanium dioxide.

However, the method for producing a catalyst electrode in Patent Document 2 requires an adhesive, requires a complicated production process, requires heat treatment, and is disadvantageous in terms of production process and production cost. In addition, titanium dioxide exemplified as an adhesive does not have catalytic ability, and has reduced catalytic ability per electrode volume. In addition, as described above, the conductive polymer itself is not used as a catalyst for the reduction reaction, and it is inferior to carbon black or the like, because the deposition of a catalytic substance is required. Only performance is expressed. Further, in the case where a conductive polymer is used, the conductivity of the conductive polymer is lowered by baking in the bonding step, and thus it cannot be said that the material is suitable for the manufacturing method. On the other hand, even when metal is deposited as a catalyst, metal corrosion by iodine cannot be avoided in the I ⁻ / I ₃ ⁻ system that is most often used as a current redox couple. On the other hand, noble metals such as platinum have not solved the cost problem at all. When carbon is used as a catalyst, the catalytic capacity is lower than that of platinum, so the catalyst layer must be thicker, and the problem of diffusion of the redox couple is more seriously affected.

Patent Document 3 discloses a dye-sensitized solar cell using a hole current collecting electrode (catalyst electrode) made of an organic film formed simultaneously with polymerization of a monomer.
According to Patent Document 3, a hole-collecting electrode can be produced at a low cost by a simple process as compared with a conventional catalyst electrode forming method, and a dye-sensitized solar cell advantageous in terms of manufacturing process and manufacturing cost can be provided. However, in terms of battery characteristics, the performance is comparable to that of a conventional dye-sensitized solar cell using a catalyst electrode using platinum.
In order to rapidly advance the iodine reduction reaction on the surface of the catalyst electrode, the surface area of the hole must be increased as in the case of the above-described catalyst electrode using platinum. The body preparation method is a method in which polymerization is advanced by applying a solution containing a monomer by spin coating and then heat-treating the solution. That is, in this production method, a catalyst electrode having a desired high surface area cannot be obtained, and further improvement in performance cannot be expected.

Moreover, although the said manufacturing method describes superposing | polymerizing poly (3,4-ethylene dioxythiophene) by heat processing, manufacturing cost will raise by heat processing. Moreover, although this material is cheaper than platinum, when practicality is considered, it is still expensive and the supply source is also limited at present. Furthermore, since heat treatment is performed, plastic or film cannot be used as an electrode body.
Further, in Patent Document 3, a plurality of elements (batteries) are formed on a common electrically insulating transparent substrate, and a structure in which the plurality of elements are connected in series is also referred to. As a method, when it is formed by directly polymerizing on a substrate, it is used by separating it into stripes so as not to contact each other by a physical method. Another method is to use a self-supporting film that is separately polymerized and filmed and then peeled off, both of which are cumbersome and are not suitable for practical use.

Patent Document 4 discloses a photoelectrochemical cell (a dye-sensitized solar cell) having a counter electrode having catalytic activity. According to Patent Document 4, the surface having the catalytic activity of the counter electrode has at least one polymer, or at least one polymer salt, or both, and the polymer or polymer salt is In addition, it is described that a redox system of an electrolytic solution results in an inherently conductive polymer.
In Patent Document 4, as a conventional technique, a photoelectrochemical cell in which a carbon layer is used as a counter electrode is introduced. Since the catalytic activity of carbon is poor, it is necessary to increase the surface area or to have catalytic activity. It is described. However, this document does not specify a substance having a specific catalytic activity, nor does it give an example.
On the other hand, as a method for producing the counter electrode, Patent Document 4 describes that a conductive layer is formed on a substrate and then a coating is formed. The conductive layer is based on a polymer and / or a polymer salt, and the polymer or polymer salt is a polymer based on any one of polyaniline, polypyrrole, and polythiophene. Yes.
Patent Document 4 also describes that the surface of the counter electrode has catalytic activity, and the surface having catalytic activity contains polyethylene dioxythiophene or consists entirely of polyethylene dioxythiophene. There is a description that it is desirable. Therefore, although polyethylene dioxythiophene coated on the conductive layer can be said to be a substance having catalytic activity, a large problem in terms of cost remains as in Patent Document 3.

Non-Patent Document 1 describes a dye-sensitized solar cell using an ionic liquid electrolyte and a poly (3,4-ethylenedioxythiophene) (PEDOT) counter electrode. In this document, as a method for producing a PEDOT counter electrode, a process of spin-coating a dispersed aqueous solution of PEDOT particles having a polystyrene sulfonate anion as a dopant on a conductive glass, drying, and further heat-treating is repeated. Have been described.
This manufacturing method is complicated and has a problem that the manufacturing cost is high because heat treatment is also performed. Moreover, it is difficult to perform patterning of elements at the time of practical use by the spin coating method. In addition, there is a problem that sufficient electrical conductivity cannot be obtained because the contact between the particles is insufficient by simply laminating the particles, and that the physical durability is low and the adjustment of the surface area is difficult. there were.
Patent Document 5 discloses a dye-sensitized solar cell using a conductive substrate formed from a conductive polyaniline dispersion.
Various techniques have been proposed, but there is a need for a dye-sensitized solar cell that can be produced with a lower manufacturing cost and process and that exhibits excellent battery characteristics.

JP-A-7-226527 Japanese National Patent Publication No. 11-514787 JP 2003-317814 A JP 2001-43908 A JP 2005-317528 A Abstracts of the 72nd Annual Meeting of the Electrochemical Society of Japan, April 1, 2005, p.471

In view of the above-described circumstances, the present invention is a catalyst electrode for a dye-sensitized solar cell, which can be produced by an inexpensive material and a simple manufacturing method, and can quickly produce an oxidant of a redox pair contained in an electrolyte. An object of the present invention is to provide a catalyst electrode excellent in durability that can be reduced to a low level.
The object of the present invention is also to easily manufacture a porous catalyst electrode for use in a dye-sensitized solar cell facing the semiconductor electrode via an electrolyte layer, by using an inexpensive material without using a binder. An object of the present invention is to provide a method for producing an electrode having good operability and excellent electrode characteristics with small energy. The object of the present invention is also excellent in adhesion and current collection with a current collector, having a large surface area, and capable of rapidly reducing an oxidant of a redox pair contained in an electrolyte. It is an object of the present invention to provide a porous catalyst electrode for a dye-sensitized solar cell excellent in the above.
The object of the present invention is also excellent in that it can be produced by an inexpensive material and a simple manufacturing method, and can quickly reduce the oxidant of the redox couple contained in the electrolyte even in a thinner film thickness than before. It is to provide a catalytic electrode.
Another object of the present invention is to provide a dye-sensitized solar cell having the above catalyst electrode and having excellent photoelectric conversion efficiency, and to provide a transparent dye-sensitized solar cell if desired. It is.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that in a catalyst electrode for a dye-sensitized solar cell, a conductive polymer such as a polymer of aniline or an aniline derivative, or an aniline and aniline derivative. It has been found that an electrode including a conductive polymer layer using a copolymer of two or more kinds of comonomers can be a catalyst electrode that can rapidly reduce an oxidized form of a redox couple.
The inventors of the present invention can also easily produce a catalyst electrode at a low cost by forming a conductive polymer layer by electrolytic polymerization on an electrode substrate, and the conductive polymer layer thus produced is a thin film. It has been found that the oxide of the redox couple can be rapidly reduced even in the thickness, and the catalyst electrode can be made transparent as desired.
Furthermore, the present inventors further formed a dense conductive polymer layer on an electrode substrate serving as a current collector / support as a structure of the catalyst electrode, and then formed an electrode on the dense conductive polymer layer. It has been found that a catalyst electrode having more excellent electrode characteristics and durability can be obtained by forming a structure of three or more layers provided with a porous conductive polymer layer as an active part.

Therefore, the present invention provides a dye-sensitized solar cell having a light-transmitting semiconductor electrode containing a dye having a photosensitizing action and an electrolyte layer containing a chemical species that serves as a redox pair, with the electrolyte layer interposed therebetween. The catalyst electrode is disposed opposite to the semiconductor electrode, and has a conductive polymer layer on the electrode substrate.
Examples of the monomer that forms the conductive polymer include aromatic amine compounds, and more specifically, aniline and aniline derivatives. Examples of the aniline derivative include anisidine, phenetidine, toluidine, phenylenediamine, hydroxyaniline, and N-methylaniline. Other examples of the aniline derivative include trifluoromethaneaniline, nitroaniline, cyanoaniline, and halogenated aniline. A thiophene compound is mentioned as another monomer which forms the said conductive polymer. Thiophene compounds include thiophene and thiophene derivatives, such as tetradecylthiophene, isothianaphthene, 3-phenylthiophene, 3,4-ethylenedioxythiophene, 3-methylthiophene, 3-butylthiophene, 3 -Octylthiophene. Examples of another monomer that forms the conductive polymer include pyrrole, pyrrole derivatives, furan, pyridine, and benzene. Examples of the pyrrole derivative include 3-methylpyrrole, 3-butylpyrrole, and 3-octylpyrrole.

The present invention also provides a dye-sensitized solar cell having at least a light-transmitting semiconductor electrode containing a dye having a photosensitizing action and an electrolyte layer containing a chemical species serving as a redox pair, with the electrolyte layer interposed therebetween. The catalyst electrode is disposed opposite to the semiconductor electrode, and includes at least an electrode base and a conductive polymer layer formed by electrochemical polymerization on the electrode base. It is.
The present invention also provides a dye-sensitized solar cell having at least a light-transmitting semiconductor electrode containing a dye having a photosensitizing action and an electrolyte layer containing a chemical species serving as a redox pair, with the electrolyte layer interposed therebetween. A method for producing a catalyst electrode disposed opposite to the semiconductor electrode, the method comprising forming a conductive polymer layer on the electrode substrate by electrochemical polymerization.

（上記式中、Ｒ₁〜Ｒ₈はそれぞれ独立に水素原子、アルキル基、アルコキシ基、アリール基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、ヒドロキシル基、チオール基、カルボキシル基、スルホ基、又はホスホニウム基を示し、式（A）中、Ｒ₁とＲ₂、又はＲ₃とＲ₄はそれぞれ連結して環を形成していてもよく、式（B）中、Ｒ₆Ｒ₇、又はＲ₇とＲ₈はそれぞれ連結して環を形成していてもよい。）
上記芳香族アミン化合物として、アニリン、アニシジン、トルイジン、フェニレンアジアミンなどがある。As a monomer for forming the conductive polymer by the above electrochemical polymerization, there is an aromatic amine compound represented by the following formula.

(In the above formula, R _{1 to} R ₈ are each independently a hydrogen atom, alkyl group, alkoxy group, aryl group, cyano group, thiocyano group, halogen group, nitro group, amino group, hydroxyl group, thiol group, carboxyl group, A sulfo group or a phosphonium group, and in formula (A), R ₁ and R ₂ , or R ₃ and R ₄ may be linked to form a ring, and in formula (B), R ₆ R ₇ or R ₇ and R ₈ may be linked to each other to form a ring.)
Examples of the aromatic amine compound include aniline, anisidine, toluidine, and phenylenediamine.

（式（１）又は（２）中、Ｒ₁及びＲ₆はそれぞれ独立に水素原子、メチル基又はエチル基を示し、Ｒ₂〜Ｒ₅及びＲ₇〜Ｒ₁₀はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、炭素原子数６〜１２のアラルキル基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、アミド基、ヒドロキシル基、チオール基、カルボキシル基、スルホ基、又はホスホニウム基を示し、式（１）中、Ｒ₂とＲ₃、又はＲ₄とＲ₅はそれぞれ連結して環を形成していてもよく、式（２）中、Ｒ₈とＲ₉、又はＲ₉とＲ₁₀はそれぞれ連結して環を形成していてもよい。）As a monomer for forming the conductive polymer by the above electrochemical polymerization, there is an aromatic amine compound represented by the following general formula (1) or (2).

(In the formula (1) or (2), R ₁ and R ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and R _{2 to} R ₅ and R _{7 to} R ₁₀ each independently represent a hydrogen atom or carbon. An alkyl group or an alkoxy group having 1 to 8 atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, a halogen group, a nitro group, an amino group, an amide group, A hydroxyl group, a thiol group, a carboxyl group, a sulfo group, or a phosphonium group, and in formula (1), R ₂ and R ₃ , or R ₄ and R ₅ may be linked to form a ring, In formula (2), R ₈ and R ₉ , or R ₉ and R ₁₀ may be linked to form a ring.)

（式（３）中、Ｒ₁₁、Ｒ₁₂はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、カルボキシル基、スルホ基、又はホスホニウム基を示し、Ｒ₁₁とＲ₁₂は連結して環を形成していてもよい。）
該チオフェン化合物として、チオフェン、3-メチルチオフェン、3-ブチルチオフェン、3-オクチルチオフェン、テトラデシルチオフェン、イソチアナフテン、3-フェニルチオフェン、3,4-エチレンジオキシチオフェンなどが挙げられる。Examples of the monomer that forms the conductive polymer by electrochemical polymerization include a thiophene compound represented by the following general formula (3).

(In Formula (3), R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an alkoxy group, an aryl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, and a halogen group. Nitro group, amino group, carboxyl group, sulfo group, or phosphonium group, and R ₁₁ and R ₁₂ may be linked to form a ring.)
Examples of the thiophene compound include thiophene, 3-methylthiophene, 3-butylthiophene, 3-octylthiophene, tetradecylthiophene, isothianaphthene, 3-phenylthiophene, and 3,4-ethylenedioxythiophene.

The present invention further provides a dye-sensitized solar cell having a light-transmitting semiconductor electrode containing a dye having a photosensitizing action, and an electrolyte layer containing a chemical species that serves as a redox pair, via the electrolyte layer. A porous catalyst electrode disposed opposite to the semiconductor electrode, the electrode having a conductive polymer layer formed by densely polymerizing a monomer that forms a conductive polymer on the surface of the electrode substrate; It is a porous catalyst electrode having a porous conductive polymer layer obtained by polymerizing a monomer that forms a conductive polymer as a working part of the electrode on the molecular layer.
The present invention further provides a dye-sensitized solar cell having a light-transmitting semiconductor electrode containing a dye having a photosensitizing action, and an electrolyte layer containing a chemical species that serves as a redox pair, via the electrolyte layer. A method for producing a porous catalyst electrode disposed opposite to a semiconductor electrode, wherein (a) a conductive polymer layer is formed on a surface of an electrode substrate by densely polymerizing a monomer that forms a conductive polymer. And a step of causing
(b) a step of forming a porous conductive polymer layer obtained by polymerizing a monomer that forms a conductive polymer on the conductive polymer layer as an active part of the electrode. It is a manufacturing method.

  An aromatic compound is mentioned as a monomer which forms this conductive polymer of the conductive polymer layer or porous conductive polymer layer formed by the above-mentioned dense polymerization. Specific examples of the aromatic compound include pyrrole, pyrrole derivatives, thiophene, thiophene derivatives, aniline, aniline derivatives, furan, pyridine, benzene and the like. In addition, a part of hydrogen atoms of these aromatic compounds may be an alkyl group having up to 8 carbon atoms, an alkoxy group or an aryl group, a cyano group, a thiocyano group, a halogen group, a nitro group, an amino group, a carboxyl group, a sulfo group, or a phosphonium. A compound substituted with a group may be used. Specific examples of the pyrrole derivative include 3-methylpyrrole, 3-butylpyrrole, and 3-octylpyrrole. Examples of the thiophene derivative include 3-methylthiophene, 3-butylthiophene, 3-octylthiophene, tetradecylthiophene, There are isothianaphthene, 3-phenylthiophene, 3,4-ethylenedioxythiophene, and examples of aniline derivatives are anisidine, phenetidine, toluidine, phenylenediamine, hydroxyaniline, N-methylaniline, trifluoromethaneaniline, nitroaniline , Cyanoaniline, and halogenated aniline.

The present invention further includes a light-transmitting semiconductor electrode containing a dye having a photosensitizing action, an electrolyte layer containing at least a chemical species serving as a redox pair, and the semiconductor electrode disposed opposite to the electrolyte layer. A dye-sensitized solar cell having at least a catalyst electrode, the catalyst electrode being directed to the dye-sensitized solar cell which is the catalyst electrode.
As an example of the embodiment of the dye-sensitized solar cell of the present invention, there is an integrated dye-sensitized solar cell in which a plurality of semiconductor electrodes are arranged to face a catalyst electrode. Specifically, two or more semiconductor electrodes are electrolytes. There is a dye-sensitized solar cell in which a conductive polymer layer is present at least in a portion of the catalyst electrode facing the semiconductor electrode, which is disposed to face one catalyst electrode through the layer.

  ADVANTAGE OF THE INVENTION According to this invention, the catalyst electrode which can reduce | restore the oxidation body of the oxidation reduction pair contained in electrolyte rapidly, and a dye-sensitized solar cell provided with this and having the photoelectric conversion efficiency excellent in durability are provided. Can be provided. The reason why the reduction reaction rate can be increased in the catalyst electrode of the present invention is unclear. However, in addition to the remarkably high reduction catalytic ability of the redox couple of the polyaniline skeleton with respect to the oxidized form, an aromatic amine compound, for example, a homopolymer or copolymer using an aniline derivative as a monomer, or an aromatic other than aniline and aniline By using a copolymer with an amine compound (for example, an aniline derivative) as a comonomer, the reaction activity is improved compared to polyaniline alone, so the charge density and steric effect of the conductive polymer are considered to have an effect. It is done.

In addition, by using an aromatic amine compound other than aniline, such as an aniline derivative, the elimination potential of the dopant accompanying the reduction reaction can be suppressed sterically or by shifting the reduction potential of the conductive polymer. The present inventors consider that the durability is further improved because the photoelectric conversion efficiency can be maintained.
Such a polymerization step of aniline and aniline derivatives also has an advantage that it can be produced by a very simple and inexpensive method such as chemical polymerization in which an oxidant is reacted or electrochemical oxidation polymerization. Further, when aniline and an aniline derivative are polymerized, it is considered that a fibrillated porous membrane can be easily obtained and that a large surface area can be secured, which also leads to an increase in the reduction reaction rate.

Furthermore, by adopting electrochemical oxidative polymerization for the formation of the conductive polymer layer of the catalyst electrode, it is possible to electrically control the polymerization of the conductive polymer in a room temperature air atmosphere. A conductive polymer film can be selectively formed on the part, the film thickness can be easily adjusted, and the patterning is excellent, simple and easy to operate, and the production amount per hour is large and inexpensive. A catalyst electrode including a conductive polymer layer can be manufactured with good reproducibility at a manufacturing cost. Furthermore, since an electrode can be formed without using an additive such as a binder that essentially lowers electrode characteristics, the catalyst activity per volume is improved.
Further, even when a monomer having a relatively high oxidation potential such as a thiophene compound is used, there is an advantage that the oxidative polymerization can be easily performed electrochemically.
The reason why the catalyst electrode of the present invention can increase the reduction reaction rate by including the conductive polymer layer by electrochemical oxidative polymerization is considered as follows. The conductive polymer layer produced by electrochemical polymerization is superior in conductivity to the case where it is formed by a chemical polymerization method using an oxidizing agent or the like, and is formed in a porous state. Therefore, the surface area is increased, and electron exchange with the redox couple can be performed efficiently. In particular, as described above, aniline and aniline derivatives are advantageous because they become porous easily by an electrochemical polymerization method.
As described above, the catalyst electrode of the present invention can quickly reduce the oxidized form of the redox couple contained in the electrolyte even when the thickness is relatively thin, and the conductive polymer layer while maintaining high performance. Therefore, transparency can be imparted and the manufacturing cost can be reduced.

Further, according to the method of the present invention, a dense conductive polymer layer is formed on an electrode substrate serving as a current collector / support, and then the porous conductive layer is formed on the dense conductive polymer layer as a working part of the electrode. By forming a structure of three or more layers provided with a conductive polymer layer, it has excellent adhesion to the current collector and current collection, and quickly reduces the oxidant of the redox couple contained in the electrolyte. A porous catalyst electrode can be produced.
The reason why an electrode having a high conductivity and excellent electrode characteristics can be obtained in the catalyst electrode having the above three-layer structure is considered as follows.
That is, by providing a polymer layer having high conductivity by densely polymerizing the monomer between the porous conductive polymer layer serving as the active part of the electrode and the electrode substrate functioning as a current collector. Thus, it becomes possible to improve the adhesion between the electrode action portion and the electrode substrate, and to improve the conductivity, current collection, and durability of the porous conductive polymer. Furthermore, by covering the entire surface of the electrode substrate with a conductive polymer having high conductivity, the potential applied to the electrode is stabilized, and the oxidant of the redox pair is reduced by reducing local electric field concentration. It can be reduced quickly.
Moreover, it can contribute to the improvement of an electrode characteristic by making the action | operation part of an electrode into a porous state as mentioned above.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings as appropriate.
FIG. 1 is a schematic cross-sectional view showing an example of the dye-sensitized solar cell of the present invention. In the dye-sensitized solar cell, a porous metal oxide semiconductor layer 4 is formed on the surface of an electrode substrate 1 comprising a transparent substrate 2 and a transparent conductive film 3 formed thereon, and the porous metal oxide is further oxidized. A sensitizing dye layer 5 is adsorbed on the surface of the physical semiconductor layer 4. And the catalyst electrode 7 of this invention is installed facing through the electrolyte layer 6. FIG.
FIG. 2 is a schematic cross-sectional view showing an example of the catalyst electrode of the present invention, in which the catalyst electrode 7 has an electrode substrate 8 that functions as a support and aggregate, and a conductive polymer layer 9 on the surface thereof. Consists of. FIG. 3 is a schematic cross-sectional view showing an example of the catalyst electrode of the present invention. In the catalyst electrode 7, a monomer for forming a conductive polymer is formed on the surface of the electrode substrate 8 that functions as a support and current collector. A porous conductive polymer layer 11 is provided on the conductive polymer layer 10 that is densely polymerized and on the dense conductive polymer layer 10 as an active part of the electrode.

Hereinafter, a suitable form is demonstrated about each structural material of the dye-sensitized solar cell of this invention.
[Transparent substrate]
As the transparent substrate 2 constituting the electrode substrate 1, one that transmits visible light can be used, and transparent glass can be suitably used. Moreover, the thing which processed the glass surface and scattered incident light, and a translucent ground glass-like thing can also be used. Moreover, not only glass but a plastic plate, a plastic film, etc. can be used if it transmits light.
The thickness of the transparent substrate 2 is not particularly limited because it varies depending on the shape and use conditions of the solar cell. Yes, flexibility is required, and when a plastic film or the like is used, it is about 1 μm to 1 mm.

[Transparent conductive film]
As the transparent conductive film 3, a material that transmits visible light and has conductivity can be used, and examples of such a material include metal oxide. Although not particularly limited, for example, tin oxide doped with fluorine (hereinafter abbreviated as “FTO”), indium oxide, a mixture of tin oxide and indium oxide (hereinafter abbreviated as “ITO”), and oxidation. Zinc or the like can be suitably used. In addition, an opaque conductive material can be used as long as visible light is transmitted through a treatment such as dispersion. Such materials include carbon materials and metals. Although it does not specifically limit as a carbon material, For example, graphite (graphite), carbon black, glassy carbon, a carbon nanotube, fullerene, etc. are mentioned. Further, the metal is not particularly limited, and examples thereof include platinum, gold, silver, ruthenium, copper, aluminum, nickel, cobalt, chromium, iron, molybdenum, titanium, tantalum, and alloys thereof. Therefore, the transparent conductive film 3 can be formed by providing a conductive material composed of at least one of the above-described conductive materials on the surface of the transparent substrate 2. Alternatively, it is also possible to incorporate the conductive material into the material constituting the transparent substrate 2 and integrate the transparent substrate and the transparent conductive film into the electrode substrate 1.

As a method for forming the transparent conductive film 3 on the transparent substrate 2, in the case of forming a metal oxide, there are a sol-gel method, a vapor phase method such as sputtering and CVD, and a coating of a dispersion paste. Moreover, when using an opaque electroconductive material, the method of fixing a powder etc. with a transparent binder etc. is mentioned.
In order to integrate the transparent substrate and the transparent conductive film, the conductive film material may be mixed as a conductive filler when the transparent substrate is molded.
The thickness of the transparent conductive film 3 is not particularly limited because the conductivity varies depending on the material to be used, but is generally 0.01 μm to 5 μm, preferably 0.1 μm to 1 μm in the FTO-coated glass. It is. Further, the required conductivity varies depending on the area of the electrode to be used, and a wider electrode is required to have a lower resistance, but is generally 100Ω / □ or less, preferably 10Ω / □ or less, more preferably 5Ω. / □ or less.
The thickness of the electrode substrate 1 composed of a transparent substrate and a transparent conductive film, or the electrode substrate 1 in which the transparent substrate and the transparent conductive film are integrated varies depending on the shape and use conditions of the solar cell as described above, and thus is particularly limited. Generally, it is about 1 μm to 1 cm.

[Porous metal oxide semiconductor]
Examples of the porous metal oxide semiconductor 4 include, but are not limited to, titanium oxide, zinc oxide, tin oxide, and the like. Particularly, titanium dioxide and further anatase type titanium dioxide are preferable. Further, it is desirable that the metal oxide has few grain boundaries in order to reduce the electric resistance value. In order to adsorb more sensitizing dye, the semiconductor layer is preferably porous, specifically 10 to 200 m ² / g. Further, in order to increase the light absorption amount of the sensitizing dye, it is desirable to scatter the light by making the particle diameter of the oxide to be used wide.
Such a porous metal oxide semiconductor is not particularly limited and can be provided on the transparent conductive film 3 by a known method. For example, there are a sol-gel method, dispersion paste application, electrodeposition and electrodeposition.
The thickness of such a semiconductor layer is not particularly limited because the optimum value varies depending on the oxide used, but is 0.1 μm to 50 μm, preferably 5 to 30 μm.

[Sensitizing dye]
The sensitizing dye layer 5 is not particularly limited as long as it can be excited by sunlight and can inject electrons into the metal oxide semiconductor layer 4, and a dye generally used in dye-sensitized solar cells can be used. However, in order to improve the conversion efficiency, it is desirable that the absorption spectrum overlaps with the sunlight spectrum in a wide wavelength region and the light resistance is high. Although not particularly limited, a ruthenium complex, particularly a ruthenium polypyridine complex is desirable, and a ruthenium complex represented by Ru (L) 2 (X) 2 is more desirable. Here, L is 4,4′-dicarboxy-2,2′-bipyridine, or a quaternary ammonium salt thereof, and a polypyridine-based ligand into which a carboxyl group is introduced, and X is SCN, Cl, CN It is. Examples thereof include bis (4,4′-dicarboxy-2,2′-bipyridine) diisothiocyanate ruthenium complex.
Examples of other dyes include metal complex dyes other than ruthenium, such as iron complexes and copper complexes. Further examples include organic dyes such as cyan dyes, porphyrin dyes, polyene dyes, coumarin dyes, cyanine dyes, squaric acid dyes, styryl dyes, and eosin dyes. These dyes preferably have a bonding group with the metal oxide semiconductor layer in order to improve the efficiency of electron injection into the metal oxide semiconductor layer. The linking group is not particularly limited, but a carboxyl group, a sulfonic acid group and the like are desirable.

The method for adsorbing the sensitizing dye to the porous metal oxide semiconductor 4 is not particularly limited. For example, the porous metal oxide is dissolved in a solution in which the dye is dissolved at room temperature and atmospheric pressure. A method of immersing the electrode substrate 1 on which the physical semiconductor 4 is formed may be mentioned. It is desirable that the immersion time is appropriately adjusted so that a monomolecular film of the dye is uniformly formed on the semiconductor layer depending on the type of the semiconductor, the dye, the solvent, and the concentration of the dye used. In addition, what is necessary is just to perform the immersion under a heating in order to perform adsorption | suction effectively.
Examples of the solvent used to dissolve the sensitizing dye include alcohols such as ethanol, nitrogen compounds such as acetonitrile, ketones such as acetone, ethers such as diethyl ether, halogenated aliphatic hydrocarbons such as chloroform, Examples thereof include aliphatic hydrocarbons such as hexane, aromatic hydrocarbons such as benzene, and esters such as ethyl acetate. It is desirable that the dye concentration in the solution is appropriately adjusted according to the type of dye and solvent used. For example, a concentration of 5 × 10 ⁻⁵ mol / L or more is desirable.

[Electrolyte layer]
The electrolyte layer 6 is composed of a supporting electrolyte, a redox pair capable of reducing the oxidized sensitizing dye, and a solvent for dissolving them. The solvent is not particularly limited, and can be arbitrarily selected from a non-aqueous organic solvent, a room temperature molten salt, water, a protic organic solvent, etc., for example, acetonitrile, dimethylformamide, ethylmethylimidazolium bistrifluoromethylimide, methoxyacetonitrile. , Methoxypropionitrile, propylene carbonate, and the like. Among them, methoxyacetonitrile, methoxypropionitrile, propylene carbonate, and the like can be preferably used. Further, the solvent can be used after gelation.
Examples of the supporting electrolyte include lithium salts, imidazolium salts, and quaternary ammonium salts.

The oxidation-reduction pair is not particularly limited as long as it can be generally used in a battery or a solar battery. For example, a combination of a halogen diatomic molecule and a halide salt, a thiocyanate anion and Examples include a combination of two thiocyanate molecules, a polypyridyl cobalt complex, and organic redox such as hydroquinone. Among these, a combination of iodine molecules and iodide is particularly preferable.
The supporting electrolyte, the redox couple, and the like are not particularly limited because the optimum concentration differs depending on the solvent, the semiconductor electrode, the dye, and the like used, but is about 1 mmol / L to 5 mol / L.
Further, t-butylpyridine, 1,2-dimethyl-3-propylimidazolium iodide, water, and the like can be added to the electrolyte layer as additives.

[Catalyst electrode-electrode substrate]
The catalyst electrode 7 has a structure in which a conductive polymer layer 9 is formed on the surface of an electrode substrate 8. Alternatively, the catalyst electrode 7 has a structure having a conductive polymer layer 10 formed by densely polymerizing a monomer that forms a conductive polymer on the surface of the electrode substrate 8.
Since the electrode substrate 8 is used as a support and current collector for a catalyst electrode, and when the conductive polymer layer is electrochemically polymerized on the surface of the electrode substrate, at least the conductive polymer layer is provided. The surface portion to be formed must have electrical conductivity.
As such a material, for example, a conductive metal or metal oxide, a carbon material, a conductive polymer, or the like is preferably used. Examples of the metal include platinum, gold, silver, ruthenium, copper, aluminum, nickel, cobalt, chromium, iron, molybdenum, titanium, tantalum, and alloys thereof. Although it does not specifically limit as a carbon material, For example, graphite (graphite), carbon black, glassy carbon, a carbon nanotube, fullerene etc. are mentioned. Moreover, when metal oxides, such as FTO, ITO, an indium oxide, and zinc oxide, are used, since it is transparent or translucent, the incident light quantity to a sensitizing dye layer can be increased, and it can use it conveniently.

In addition, an insulator such as glass or plastic may be used as long as at least the surface of the electrode substrate is treated. As a treatment method for maintaining conductivity in such an insulator, a method of covering a part or the whole surface of the insulating material with the above-described conductive material, for example, when using a metal, plating, electrodeposition, etc. And a gas phase method such as sputtering or vacuum deposition. When a metal oxide is used, a sol-gel method or the like can be used. In addition, one or more of the above conductive material powders may be used and mixed with an insulating material.
Furthermore, in the present invention, even when an insulating material is used as the electrode substrate 8, a conductive polymer layer described later can be provided directly on the substrate, and in this case, the conductive polymer layer alone collects current. It fulfills the functions of both body and catalyst.

The shape of the electrode substrate is not particularly limited because it can be changed according to the shape of the dye-sensitized solar cell used as the catalyst electrode, and may be a plate shape or a film shape that can be curved. Further, the electrode substrate may be transparent or opaque. However, it is desirable that the electrode substrate be transparent or translucent because the amount of light incident on the sensitizing dye layer can be increased and, in some cases, the design can be improved. . Generally, glass with an FTO film or a PEN film with an ITO film is used as the electrode substrate, but the conductivity is different depending on the material used, and therefore the thickness of the electrode substrate is not particularly limited. For example, in the FTO-coated glass, the thickness is 0.01 μm to 5 μm, preferably 0.1 μm to 1 μm. Further, the required conductivity varies depending on the area of the electrode to be used, and a wider electrode is required to have a lower resistance, but is generally 100Ω / □ or less, preferably 10Ω / □ or less, more preferably 5Ω. / □ or less.
The thickness of the electrode substrate 8 is not particularly limited because it varies depending on the shape and use conditions of the solar cell as described above, but is generally about 1 μm to 1 cm.

（式（１）又は（２）中、Ｒ₁及びＲ₆はそれぞれ独立に水素原子、メチル基又はエチル基を示し、Ｒ₂〜Ｒ₅及びＲ₇〜Ｒ₁₀はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、炭素原子数６〜１２のアラルキル基（例えばベンジル基）、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、アミド基、ヒドロキシル基、チオール基、カルボキシル基、スルホ基、又はホスホニウム基を示し、式（１）中、Ｒ₂とＲ₃、又はＲ₄とＲ₅はそれぞれ連結して環を形成していてもよく、式（２）中、Ｒ₈とＲ₉、又はＲ₉とＲ₁₀はそれぞれ連結して環を形成していてもよい。）

（式（３）中、Ｒ₁₁、Ｒ₁₂はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、カルボキシル基、スルホ基、又はホスホニウム基を示し、Ｒ₁₁とＲ₁₂は連結して環を形成していてもよい。）

（式（４）中、Ｒ₁₃、Ｒ₁₄はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、カルボキシル基、スルホ基、又はホスホニウム基を示し、Ｒ₁₃とＲ₁₄は連結して環を形成していてもよい。）[Catalyst electrode-conductive polymer layer]
The conductive polymer layer 9 in the catalyst electrode of the present invention functions as a catalyst for reducing the oxidant of the redox couple contained in the electrolyte layer. The conductive polymer layer 9 is preferably present in a porous state so that the electron transfer reaction can be performed efficiently.
The conductive polymer contained in the conductive polymer layer 9 may be one or more homopolymers, one or more copolymers, or a mixture of one or more homopolymers and one or more copolymers.
As a monomer which forms the conductive polymer contained in the conductive polymer layer 9 in the catalyst electrode of the present invention, an aromatic amine compound represented by the following general formula (1) or (2), the following general formula (3) And at least one monomer selected from the group consisting of a pyrrole compound represented by the following general formula (4).

(In the formula (1) or (2), R ₁ and R ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and R _{2 to} R ₅ and R _{7 to} R ₁₀ each independently represent a hydrogen atom or carbon. C1-C12 alkyl group or alkoxy group, C6-C12 aryl group, C6-C12 aralkyl group (for example, benzyl group), cyano group, thiocyano group, halogen group, nitro group, amino group Group, amide group, hydroxyl group, thiol group, carboxyl group, sulfo group, or phosphonium group, and in formula (1), R ₂ and R ₃ , or R ₄ and R ₅ are linked to form a ring. In formula (2), R ₈ and R ₉ , or R ₉ and R ₁₀ may be linked to form a ring.)

(In Formula (3), R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an alkoxy group, an aryl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, and a halogen group. Nitro group, amino group, carboxyl group, sulfo group, or phosphonium group, and R ₁₁ and R ₁₂ may be linked to form a ring.)

(In Formula (4), R <_13> , R <_14> is respectively independently a hydrogen atom, a C1-C8 alkyl group or an alkoxy group, a C6-C12 aryl group, a cyano group, a thiocyano group, and a halogen group. Nitro group, amino group, carboxyl group, sulfo group, or phosphonium group, and R ₁₃ and R ₁₄ may be linked to form a ring.)

  When using the aromatic amine compound, it is not particularly limited as long as the polymer polymerized by them has conductivity, but even if the polymer film of a certain aromatic amine compound alone does not have conductivity, What is necessary is just to have electroconductivity by setting it as a copolymer with aniline or another aromatic amine compound. The polymer constituting the conductive polymer layer 9 may be a homopolymer or a copolymer, and the conductive polymer layer can be formed using one or more aromatic amine compounds as monomer components.

Examples of the aromatic amine compound include aniline and aniline derivatives. More specifically, examples include aniline, anisidine, phenetidine, toluidine, phenylenediamine, hydroxyaniline, N-methylaniline, trifluoromethaneaniline, nitroaniline, cyanoaniline, and halogenated aniline. Of these, anisidine, toluidine, phenylenediamine and aniline are preferably used. Among them, aniline is particularly preferably used, and examples thereof include polymers formed by polymerizing at least aniline as a monomer. In particular, polyaniline using aniline alone as a monomer can be suitably used because of its low cost and high catalytic ability. Alternatively, a copolymer using aniline and an aromatic compound other than aniline as a monomer is also preferably used. For example, a copolymer of aniline and an aniline derivative, more specifically, aniline and anisidine, phenetidine, toluidine, phenylenediamine, hydroxyaniline, N- Mention may be made of copolymers with comonomers selected from methylaniline, trifluoromethaneaniline, nitroaniline, cyanoaniline and halogenated anilines.
When a plurality of types of aromatic amine compounds are used, their ratios are not particularly limited, but it is appropriate to polymerize the aromatic amine compounds in a molar ratio of 100 for one and 3 or more for the other. For example, when aniline and an aniline derivative are used, it is generally appropriate to polymerize the aniline and aniline derivative in a molar ratio of 100 with one being 100 and the other being 3 or more.

Examples of the thiophene compounds include thiophene and thiophene derivatives, more specifically thiophene, 3-methylthiophene, 3-butylthiophene, 3-octylthiophene, tetradecylthiophene, isothianaphthene, 3-phenylthiophene, and There are 3,4-ethylenedioxythiophene and the like. In particular, 3,4-ethylenedioxythiophene can be preferably used.
The conductive polymer layer may be formed using one or more thiophene compounds. Since the thiophene compound has a high oxidation potential, formation by electrochemical oxidative polymerization can be suitably used.

Examples of the pyrrole compound include pyrrole and pyrrole derivatives, and examples of the pyrrole derivative include those having an alkyl group having 1 to 8 carbon atoms at the 3-position. Specific examples of the pyrrole compound include pyrrole, 3-methylpyrrole, 3-butylpyrrole and 3-octylpyrrole. The conductive polymer layer may be formed using one or more pyrrole compounds.
The monomer component that forms the conductive polymer preferably has a conductivity of 10 ⁻⁹ S / cm or more as a polymerized film.

  Further, it is desirable to add a dopant to the conductive polymer layer in order to improve conductivity. The dopant is a known material, for example, a halide anion such as hexafluoroline, hexafluoroarsenic, hexafluoroantimony, tetrafluoroboron, perchloric acid, a halogen anion such as iodine, bromine, chlorine, hexafluoroline, hexafluoroarsenic, hexa Halide anions such as fluoroantimony, tetrafluoroboron and perchloric acid, alkyl group-substituted organic sulfonate anions such as methanesulfonic acid and dodecylsulfonic acid, cyclic sulfonic acid anions such as camphorsulfonic acid, benzenesulfonic acid and paratoluenesulfone 1 to 3 sulfo groups such as acid, dodecylbenzenesulfonic acid, alkyl group-substituted or unsubstituted benzenemono- or disulfonic acid anion, 2-naphthalenesulfonic acid, 1,7-naphthalenedisulfonic acid, etc. Alkyl group-substituted or unsubstituted naphthalene sulfonate anion, anthracene sulfonic acid, anthraquinone sulfonic acid, alkyl biphenyl sulfonic acid, biphenyl disulfonic acid, etc. having an acid group, substituted or unsubstituted biphenyl sulfonic acid ion, polystyrene sulfonic acid, Polymeric sulfonate anions such as sulfonated polyether, sulfonated polyester, sulfonated polyimide, naphthalene sulfonate formalin condensate, substituted or unsubstituted aromatic sulfonate anions, bissaltylate boron, biscatecholate boron, etc. Examples thereof include boron compound anions or heteropolyacid anions such as molybdophosphoric acid, tungstophosphoric acid, and tungstomolybdophosphoric acid. These dopants may be used alone or in combination of two or more.

From the viewpoint of suppressing the desorption of the dopant, the dopant is preferably an organic acid anion rather than an inorganic anion, and it is desirable that the thermal decomposition or the like hardly occur.
In addition, by making the surface of the conductive polymer film porous, the reduction reaction of the redox couple can be efficiently performed. Therefore, among the above dopants, the polymer organic acid anion is more likely to be a dense surface. A monomolecular organic acid anion is desirable.

（式（５）〜（８）中、Ｒ¹〜Ｒ²はそれぞれ独立に水素原子、炭素原子数１から１５のアルキル基、アルコキシ基、炭素原子数６〜１２のアリール基（例えばフェニル、トリル、ナフチルなど）、シアノ基、チオシアノ基、ヒドロキシル基、ハロゲン基、又はニトロ基を示し、Ｒ¹とＲ²はそれぞれ連結して環を形成していてもよい。）
この式（５）〜（８）で表される化合物が好ましい理由について、詳細は不明であるが、これらのドーパントを用いた場合、多孔質化による物理的強度の低下を防ぎながら高電導度を達成することができるためと考察している。The conductive polymer layer 9 is at least one selected from the group consisting of benzenesulfonic acid represented by the following general formulas (5) to (8), naphthalenesulfonic acid compounds, and salts thereof among the dopants. It is particularly desirable to contain as a dopant.

(In the formulas (5) to (8), R ^{1 to} R ² are each independently a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, an alkoxy group, or an aryl group having 6 to 12 carbon atoms (for example, phenyl, tolyl). , Naphthyl, etc.), cyano group, thiocyano group, hydroxyl group, halogen group, or nitro group, and R ¹ and R ² may be linked to form a ring.)
The reason why the compounds represented by the formulas (5) to (8) are preferable is not clear, but when these dopants are used, high conductivity is prevented while preventing a decrease in physical strength due to porosity. It is considered that it can be achieved.

As the dopant, iodine anions and / or polyiodide anions can also be preferably used. Although details about this reason are unclear, the present inventors consider as follows. That is, these anions contained in the conductive polymer in the present invention function as dopants that develop the high conductivity of the conductive polymer, and the redox couple in the electrolyte and Grothus mechanism (a dye for practical use). Sensitized solar cell, pp13, 2003, described in NTS Co., Ltd.), and it is considered that high catalytic ability can be obtained because charge transfer to the electrolyte can be performed more easily.
For example, iodine anion (I ⁻ ) can be provided by using LiI, HI or the like as a dopant. The polyiodide anion is in the form of, for example, I ₃ ⁻ or I ₅ ⁻ and can be provided by dissolving and coexisting iodine (I ₂ ) and I ⁻ .

The amount of dopant used in the conductive polymer layer is not particularly limited because the optimum value varies depending on the type of dopant used, but is preferably 5 to 60% by mass, and more preferably 10 to 45% by mass.
Such a dopant can be used at an appropriate stage when the conductive polymer layer is formed. For example, it can coexist with a monomer used for forming the conductive polymer. Further, after the formation of the conductive polymer layer, it can be doped by a method such as impregnating the conductive polymer with a dopant solution.

The conductive polymer layer 9 is formed on the electrode substrate 8. Examples of the method for forming the conductive polymer layer 9 include a method of forming a film from a solution in which the conductive polymer is dissolved. The solvent used in the solution is not particularly limited as long as it can dissolve the conductive polymer compound, and examples thereof include toluene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl acetate, butyl acetate, and particularly N-methyl-2. -Pyrrolidone can be suitably used.
In addition, after the conductive polymer powder is processed into a dispersion, paste or emulsion, polymer solution, or mixture containing a binder, it is formed on the electrode substrate by screen printing, spray coating, brush coating, dipping, etc. The method of making it possible is also possible.

Further, as another method for forming the conductive polymer layer, an electrolytic polymerization method or a chemical polymerization method can be suitably used. The chemical polymerization method is a method in which an oxidant is used to oxidize and polymerize a monomer that forms a conductive polymer as exemplified above (hereinafter also simply referred to as “conductive polymer monomer”). On the other hand, the electrolytic polymerization method is a method of forming a conductive polymer film on an electrode such as a metal by electrochemically oxidizing in a solution containing the conductive polymer monomer as described above.
Since it is desirable that the conductive polymer layer 9 is in a porous state having a larger surface area, the solution containing the conductive polymer monomer than the method of applying and forming a film from the solution in which the conductive polymer is dissolved. A method of chemically oxidatively polymerizing the monomer in a state where the electrode substrate 8 is in contact with the electrode substrate 8 can be used. Furthermore, the electrochemical oxidative polymerization method (electrolytic polymerization method) can electrically control the polymerization of the conductive polymer in a room temperature air atmosphere, so that the patterning property, productivity, cost, etc. From the aspect, it can be particularly preferably used.

  The oxidizing agent used in the chemical polymerization method includes iodine, bromine, bromine iodide, chlorine dioxide, iodic acid, periodic acid, chlorous acid and other halides, antimony pentafluoride, phosphorus pentachloride, phosphorus pentafluoride. , Metal halides such as aluminum chloride, molybdenum chloride, permanganate, dichromate, chromic anhydride, ferric salt, cupric salt and other high-valent metal salts, sulfuric acid, nitric acid, trifluoromethanesulfuric acid Protonic acids such as oxygen compounds such as sulfur trioxide and nitrogen dioxide, peroxo acids such as hydrogen peroxide, ammonium persulfate and sodium perborate or salts thereof, There are heteropolyacids or salts thereof, and at least one of them can be used.

  Although the above chemical polymerization method is suitable for mass production, when the polymer is reacted with an oxidant in a solution containing a conductive polymer monomer, the resulting polymer is in the form of particles or lumps, resulting in a desired porosity. It is difficult to express the properties and form the electrode shape. Therefore, the electrode substrate is immersed in a solution containing either the conductive polymer monomer or the oxidizing agent, or after applying the solution to them, the electrode substrate is subsequently immersed or applied in a solution in which the other component is dissolved. Thus, it is desirable that the polymerization proceeds on the surface of the electrode substrate to form a conductive polymer. Further, it is also possible to use a method in which polymerization is carried out by immersing in a solution containing an oxidant or applying the solution and then exposing it to monomer vapor.

  In addition, using a separately prepared conductive polymer particle dispersion or paste, a conductive polymer film is formed on the surface of the electrode substrate or the electrode substrate with the conductive film, and then subjected to the above chemical polymerization to form conductive polymer particles. A method of growing can also be performed.

  On the other hand, since the electropolymerization method can obtain a conductive polymer having a relatively high conductivity in the form of a film and the synthesis method is simple, it can be suitably used as a method for producing an electrode material. Even if the electropolymerization is directly performed on the electrode substrate or the electrode substrate with the conductive film, after the porous conductive polymer film separately prepared by the electropolymerization is peeled off, the electrode polymerization substrate or the electrode substrate with the conductive film is used. It does not matter if they are pasted together.

  The electropolymerization solvent used in the electropolymerization method is not particularly limited as long as it can dissolve the conductive polymer monomer and is stable even in the electropolymerization potential of the conductive polymer monomer. For example, water, acetonitrile, etc. Nitriles, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, carbonates such as propylene carbonate, tetrahydrofuran and the like can be used. These may be used alone or as a mixed solvent of two or more. Of the above, organic solvents having a certain degree of polarity, such as acetonitrile, methanol, propylene carbonate, tetrahydrofuran and the like, can be suitably used. Furthermore, when adding the said dopant, it is desirable that a dopant can also be melt | dissolved.

As the electropolymerization conditions, the current collector is immersed in an electropolymerization solution in which the conductive polymer monomer is dissolved in advance, and an arbitrary voltage is applied between the counter electrode placed in the same electrolysis solution. Polymerization proceeds. The conductive polymer monomer concentration at this time is not particularly limited because the optimum value varies depending on the type of the conductive polymer monomer, but generally a range of 0.01 mol / L to 10 mol / L is appropriate. A range of 0.05 to 3 mol / L is often used. In the case of coexisting a dopant, the concentration of the dopant is suitably in the range of 1/10 to 100 times the conductive polymer monomer concentration, and often in the range of 1/3 to 20 times. . The applied current density at the time of polymerization is not particularly limited because the optimum value varies depending on the type of conductive polymer monomer, but a range of 0.01 mA / cm ^{2 to} 100 mA / cm ² is appropriate, many range for 1mA / cm ² ~10mA / cm ² is used.

The required thickness of the conductive polymer layer 9 in the catalyst electrode of the present invention varies depending on the degree of porosity, but generally the range of 5 nm to 5 μm is suitable, preferably 100 nm to 3 μm. is there.
The specific surface area of the conductive polymer layer 9 in the catalyst electrode of the present invention is not particularly limited because the optimum value varies depending on the monomer used, but is usually 0.1 m ² / g or more in terms of the N ₂ -BET specific surface area, More preferably, 5 m ² / g or more is appropriate, and further 10 m ² / g or more is desirable.

[Multilayer catalyst electrode-dense conductive polymer layer and porous conductive polymer layer]
As shown in FIG. 3, the conductive polymer layer of the catalyst electrode has a structure of three or more layers in which a dense conductive polymer layer 10 and a porous conductive polymer layer 11 are formed on the electrode substrate 8. It is more preferable to use a catalyst electrode.
In this case, the dense conductive polymer layer 10 functions to improve or improve the adhesion and current collection with the electrode substrate 8 which is lowered by making the conductive polymer layer 11 porous. . Accordingly, the dense conductive polymer layer 10 is required to have conductivity, but may not function directly as a catalyst. The monomer that forms the polymer of the dense conductive polymer layer 10 may be the same as or different from the monomer that forms the polymer of the porous conductive polymer layer 11 described later. The polymer of the dense conductive polymer layer 10 may be a homopolymer formed from a single monomer or a mixture thereof, or may be a copolymer composed of two or more monomers or a mixture thereof. It may be a mixture of a homopolymer and a copolymer.
That is, the dense conductive polymer layer 10 can include one or more homopolymers, one or more copolymers, or a mixture of one or more homopolymers and one or more copolymers, The conductive polymer layer 10 and the porous conductive polymer layer 11 can contain the same or different polymers.

（式（１）又は（２）中、Ｒ₁及びＲ₆はそれぞれ独立に水素原子、メチル基又はエチル基を示し、Ｒ₂〜Ｒ₅及びＲ₇〜Ｒ₁₀はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、炭素原子数６〜１２のアラルキル基（例えばベンジル基）、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、アミド基、ヒドロキシル基、チオール基、カルボキシル基、スルホ基、又はホスホニウム基を示し、式（１）中、Ｒ₂とＲ₃、又はＲ₄とＲ₅はそれぞれ連結して環を形成していてもよく、式（２）中、Ｒ₈とＲ₉、又はＲ₉とＲ₁₀はそれぞれ連結して環を形成していてもよい。）

（式（３）中、Ｒ₁₁、Ｒ₁₂はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、カルボキシル基、スルホ基、又はホスホニウム基を示し、Ｒ₁₁とＲ₁₂は連結して環を形成していてもよい。）

（式（４）中、Ｒ₁₃、Ｒ₁₄はそれぞれ独立に水素原子、炭素原子数１〜８のアルキル基又はアルコキシ基、炭素原子数６〜１２のアリール基、シアノ基、チオシアノ基、ハロゲン基、ニトロ基、アミノ基、カルボキシル基、スルホ基、又はホスホニウム基を示し、Ｒ₁₃とＲ₁₄は連結して環を形成していてもよい。）In the dense conductive polymer layer 10, specific examples of the monomer that forms the conductive polymer are not particularly limited, but generally include aromatic compounds. Further, as the aromatic compound monomer, an aromatic amine compound represented by the following general formula (1) or (2), a thiophene compound represented by the following general formula (3), and the following general formula (4) And at least one monomer selected from the group consisting of pyrrole compounds, furan, pyridine, benzene and the like.
Some of the hydrogen atoms of these aromatic compounds are alkyl groups, alkoxy groups or aryl groups having up to 8 carbon atoms, cyano groups, thiocyano groups, halogen groups, nitro groups, amino groups, carboxyl groups, sulfo groups, or phosphonium groups. You may use the compound substituted by.

(In the formula (1) or (2), R ₁ and R ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and R _{2 to} R ₅ and R _{7 to} R ₁₀ each independently represent a hydrogen atom or carbon. C1-C12 alkyl group or alkoxy group, C6-C12 aryl group, C6-C12 aralkyl group (for example, benzyl group), cyano group, thiocyano group, halogen group, nitro group, amino group Group, amide group, hydroxyl group, thiol group, carboxyl group, sulfo group, or phosphonium group, and in formula (1), R ₂ and R ₃ , or R ₄ and R ₅ are linked to form a ring. In formula (2), R ₈ and R ₉ , or R ₉ and R ₁₀ may be linked to form a ring.)

(In Formula (3), R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an alkoxy group, an aryl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, and a halogen group. Nitro group, amino group, carboxyl group, sulfo group, or phosphonium group, and R ₁₁ and R ₁₂ may be linked to form a ring.)

(In Formula (4), R <_13> , R <_14> is respectively independently a hydrogen atom, a C1-C8 alkyl group or an alkoxy group, a C6-C12 aryl group, a cyano group, a thiocyano group, and a halogen group. Nitro group, amino group, carboxyl group, sulfo group, or phosphonium group, and R ₁₃ and R ₁₄ may be linked to form a ring.)

Examples of the aromatic amine compound include aniline and aniline derivatives. Examples of the thiophene compound include thiophene and thiophene derivatives. Examples of the pyrrole compound include pyrrole and pyrrole derivatives. What has a C1-C8 alkyl group is mentioned.
Among these, pyrrole and pyrrole derivatives, thiophene and thiophene derivatives, and aniline and aniline derivatives that can form a conductive polymer having high conductivity are preferably used.
Examples of preferred pyrrole compounds include pyrrole, 3-methylpyrrole, 3-butylpyrrole, and 3-octylpyrrole, and at least one of them can be used. Examples of preferred thiophene compounds include thiophene, 3-methylthiophene, 3-butylthiophene, 3-octylthiophene, tetradecylthiophene, isothianaphthene, 3-phenylthiophene, and 3,4-ethylenedioxythiophene. At least one of these can be used. In particular, 3,4-ethylenedioxythiophene is preferable.
Examples of preferred aromatic amine compounds include aniline, anisidine, phenetidine, toluidine, phenylenediamine, hydroxyaniline, N-methylaniline, trifluoromethaneaniline, nitroaniline, cyanoaniline, and halogenated aniline. Can be used.

For example, a polypyrrole film formed by electrolytic polymerization is often dense and is suitable for the dense conductive polymer layer 10. On the other hand, polyaniline formed by electrolytic polymerization tends to become porous, and thus is suitable for the porous conductive polymer layer 11.
The monomer component forming the polymer of the conductive polymer layer is preferably one having a conductivity of 10 ⁻⁹ S / cm or more as a polymerized film.

Examples of a method for forming the dense conductive polymer layer 10 include a method of forming a film from a solution in which a conductive polymer is dissolved. The solvent used in the solution is not particularly limited as long as it can dissolve the conductive polymer compound, and examples thereof include toluene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl acetate, butyl acetate, and particularly N-methyl-2. -Pyrrolidone can be suitably used.
In addition, after the conductive polymer powder is processed into a dispersion, paste or emulsion, polymer solution, or mixture containing a binder, it is formed on the electrode substrate by screen printing, spray coating, brush coating, dipping, or the like. A method is also possible.

As another method for forming the dense conductive polymer layer 10 to be in close contact with the electrode substrate 8, a polymerization method such as an electrolytic polymerization method or a chemical polymerization method can also be used. As the polymerization method, an appropriate method can be selected depending on the type of the conductive polymer monomer to be used.
The electrolytic polymerization method can be suitably used because it can control the porosity and densification depending on the polymerization conditions. The conditions for forming the conductive polymer layer 10 more precisely are not particularly limited because the optimum polymerization conditions differ depending on the type of the conductive polymer to be formed and the material of the electrode substrate. Write.
For example, the electropolymerization solvent used in the electropolymerization method is not particularly limited as long as the conductive polymer monomer can be dissolved and the electropolymerization potential of the monomer is stable. For example, nitriles such as water and acetonitrile can be used. System, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, carbonates such as propylene carbonate, tetrahydrofuran and the like can be used. These may be used alone or as a mixed solvent of two or more. Of the above, organic solvents having a certain degree of polarity, such as acetonitrile, methanol, propylene carbonate, tetrahydrofuran and the like, can be suitably used. Furthermore, when adding a dopant, it is desirable that the dopant can also be dissolved.

In addition, as an electropolymerization condition, the current collector is immersed in an electropolymerization solution in which the conductive polymer monomer is dissolved in advance, and an arbitrary voltage is applied between the counter electrode placed in the same electrolysis solution. Polymerization proceeds by application. In general, it is preferable to reduce the electrolytic current density or the electrolytic potential within the range where oxidative polymerization occurs, and to lower the reaction temperature, because the densification becomes more precise. The monomer concentration at this time is not particularly limited because the optimum value varies depending on the type of monomer, but is generally in the range of 0.01 mol / L to 10 mol / L. The applied current density at the time of polymerization is not particularly limited because the optimum value varies depending on the type of monomer, but it is preferably in the range of 0.01 mA / cm ^{2 to} 100 mA / cm ² . Further, the temperature at the time of polymerization needs to be within the range in which the polymerization proceeds and within the range in which the electrolytic polymer does not boil and solidify and the conductive polymer monomer or dopant is dissolved, In particular, the temperature is particularly preferably room temperature or lower.

  Moreover, a chemical polymerization method can also be suitably used as the polymerization method. In this case, when an oxidizing agent is allowed to act in a solution containing a conductive polymer monomer, the resulting polymer is in the form of particles or lumps, and it is difficult to mold it into an electrode shape. Therefore, the electrode substrate is immersed in a solution containing either the conductive polymer monomer or the oxidizing agent, or after applying the solution to them, the electrode substrate is subsequently immersed or applied in a solution in which the other component is dissolved. Thus, it is desirable that the polymerization proceeds on the surface of the electrode substrate to form a conductive polymer layer.

  However, in order to form the conductive polymer layer 10 more precisely, a method in which the monomer is chemically oxidatively polymerized while the electrode substrate 8 is in contact with the solution containing the conductive polymer monomer as described above. Instead, a conductive polymer solution is prepared by dissolving a conductive polymer prepared by a chemical polymerization method in an arbitrary solvent, and the conductive polymer solution is spin-coated or bar-coated, or brushed or sprayed. It is more desirable to form the conductive polymer layer 10 densely and uniformly by coating and drying by coating, an inkjet method or the like.

  Further, it is desirable to add a dopant to the conductive polymer layer 10 in order to improve conductivity. The dopant is not particularly limited, and a known dopant as described in the conductive polymer layer 9 can be used. Examples of dopants include hexafluorolin, hexafluoroarsenic, hexafluoroantimony, tetrafluoroboron, halide anions such as perchloric acid, halogen anions such as iodine, bromine, and chlorine, hexafluoroline, hexafluoroarsenic, hexafluoroantimony, tetra Halogenated anions such as fluoroboron and perchloric acid, alkyl group-substituted organic sulfonic acid anions such as methanesulfonic acid and dodecylsulfonic acid, cyclic sulfonic acid anions such as camphorsulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, dodecylbenzene Alkyl group-substituted or unsubstituted benzene mono- or disulfonic acid anion such as sulfonic acid and benzene disulfonic acid, 1 to 3 sulfonic acid groups such as 2-naphthalenesulfonic acid and 1,7-naphthalenedisulfonic acid Alkyl group-substituted or unsubstituted naphthalene sulfonate anion, anthracene sulfonic acid, anthraquinone sulfonic acid, alkyl biphenyl sulfonic acid, biphenyl disulfonic acid, etc., alkyl group-substituted or unsubstituted biphenyl sulfonic acid ion, polystyrene sulfonic acid, sulfonated polyether , Polymer sulfonate anions such as sulfonated polyester, sulfonated polyimide, naphthalene sulfonate formalin condensate, substituted or unsubstituted aromatic sulfonate anions, boron compound anions such as bissaltylate boron and biscatecholate boron, Or heteropoly acid anions, such as molybdophosphoric acid, tungstophosphoric acid, tungstomolybdophosphoric acid, etc. are mentioned. These dopants may be used alone or in combination of two or more.

In order to suppress the desorption of the dopant, the dopant is preferably an organic acid anion rather than an inorganic anion, and is preferably one that is less susceptible to thermal decomposition. Furthermore, in order to form a polymer film with higher density and higher electrical conductivity and improved adhesion, among the above dopants, a polymeric anion, particularly a polymeric organic acid anion, is preferable to a monomolecular anion. More specifically, it is desirable to use a polymer sulfonate anion such as polystyrene sulfonate, polyvinyl sulfonate, sulfonated polyester, sulfonate polyether, and sulfonate polyimide.
The amount of dopant used in the dense conductive polymer layer 10 is not particularly limited because the optimum value varies depending on the type of dopant used, but is preferably 5 to 60% by mass, more preferably 10 to 45% by mass.
Such a dopant can be used at an appropriate stage when the conductive polymer layer is formed. For example, it can coexist with a monomer used for forming the conductive polymer. When the dopant is allowed to coexist in the electropolymerization, the dopant concentration is preferably in the range of 1/10 to 100 times the monomer concentration.

The thickness of the dense conductive polymer layer 10 is not particularly limited, but if the thickness is too thick, the stress of the conductive polymer layer 10 becomes strong. Since the conductive polymer layer 10 is easily peeled off from the electrode substrate 8 due to electrolyte doping, electrolyte solvent swelling, and the like, it is desirable that the conductive polymer layer 10 is thin because the electrical resistance value increases. Therefore, it is desirable to change appropriately according to the purpose and conditions of use of the electrode, and the dense conductive polymer layer 10 is desirably thinner than the porous conductive polymer layer 11.
In general, the thickness of the conductive polymer layer 10 is suitably about 5 nm to 5 μm, preferably 1 μm or less.
Specific surface area of the dense conductive polymer layer 10 in the catalyst electrode having a structure of three or more layers in which the dense conductive polymer layer 10 and the porous conductive polymer layer 11 are formed on the electrode substrate 8. Is not particularly limited because the optimum value varies depending on the monomer used, but is usually 0.1 m ² / g or more in terms of the N ₂ -BET specific surface area, and is more specific than the porous conductive polymer layer 11. Is preferably small, specifically 5 m ² / g or less.

On the other hand, since the porous conductive polymer layer 11 functions as a catalyst for reducing the oxidized form of the redox couple contained in the electrolyte layer, the components and the formation method of the porous conductive polymer layer 11 are generally Specifically, it may conform to the conductive polymer layer 9 described above.
As long as the porous conductive polymer layer 11 has conductivity and a catalytic function, the monomer constituting the conductive polymer is not particularly limited. The polymer of the porous conductive polymer layer 11 may be a homopolymer formed from a single monomer or a mixture thereof, a copolymer composed of two or more monomers, or a mixture thereof. It may be a mixture of a homopolymer and a copolymer. That is, the dense conductive polymer layer 11 can include one or more homopolymers, one or more copolymers, or a mixture of one or more homopolymers and one or more copolymers.
The porous conductive polymer layer 11 may be configured by using a conductive polymer to be made porous and a conductive polymer that works as a catalyst.

In the porous conductive polymer layer 11, specific examples of the monomer that forms the conductive polymer are not particularly limited, but generally include aromatic compounds. Further, as the aromatic compound monomer, the aromatic amine compound represented by the general formula (1) or (2), the thiophene compound represented by the general formula (3), or the general formula (4) And at least one monomer selected from the group consisting of pyrrole compounds, furan, pyridine, benzene and the like. Among these, aromatic amine compounds, thiophene compounds and pyrrole compounds can be particularly preferably used.
Some of the hydrogen atoms of these aromatic compounds are alkyl groups, alkoxy groups or aryl groups having up to 8 carbon atoms, cyano groups, thiocyano groups, halogen groups, nitro groups, amino groups, carboxyl groups, sulfo groups, or phosphonium groups. You may use the compound substituted by.

Examples of the aromatic amine compound include aniline and aniline derivatives. Examples of the thiophene compound include thiophene and thiophene derivatives. Examples of the pyrrole compound include pyrrole and pyrrole derivatives. What has a C1-C8 alkyl group is mentioned.
Among these, pyrrole and pyrrole derivatives, thiophene and thiophene derivatives, and aniline and aniline derivatives that can form a conductive polymer having high conductivity are preferably used.
Examples of preferred pyrrole compounds include pyrrole, 3-methylpyrrole, 3-butylpyrrole, and 3-octylpyrrole, and at least one of them can be used. Examples of preferred thiophene compounds include thiophene, 3-methylthiophene, 3-butylthiophene, 3-octylthiophene, tetradecylthiophene, isothianaphthene, 3-phenylthiophene, and 3,4-ethylenedioxythiophene. At least one of these can be used. In particular, 3,4-ethylenedioxythiophene is preferable.

Examples of preferred aromatic amine compounds include aniline, anisidine, phenetidine, toluidine, phenylenediamine, hydroxyaniline, N-methylaniline, trifluoromethaneaniline, nitroaniline, cyanoaniline, and halogenated aniline. Can be used. For example, at least aniline may be used as a monomer, and polyaniline or a copolymer using an aromatic compound other than aniline and aniline as a monomer may be used. For example, a copolymer of aniline and an aniline derivative, more specifically, selected from aniline and anisidine, phenetidine, toluidine, phenylenediamine, hydroxyaniline, N-methylaniline, trifluoromethaneaniline, nitroaniline, cyanoaniline and halogenated aniline. Copolymers with comonomers are mentioned.
The monomer component forming the polymer of the conductive polymer layer is preferably one having a conductivity of 10 ⁻⁹ S / cm or more as a polymerized film.

Examples of a method for forming the porous conductive polymer layer 11 include a method of forming a film from a solution in which a conductive polymer is dissolved. The solvent used in the solution is not particularly limited as long as it can dissolve the conductive polymer compound, and examples thereof include toluene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl acetate, butyl acetate, and particularly N-methyl-2. -Pyrrolidone can be suitably used.
In addition, after the conductive polymer powder is processed into a dispersion, paste or emulsion, polymer solution, or mixture containing a binder, it is formed on the electrode substrate by screen printing, spray coating, brush coating, dipping, or the like. A method is also possible.

  A chemical polymerization method can also be used as a method for forming the porous conductive polymer layer 11. When using the chemical polymerization method, if the polymer is reacted with an oxidizing agent in a solution containing a conductive polymer monomer, the resulting polymer will be in the form of particles or lumps, and will exhibit the desired porosity. It is difficult to mold into an electrode shape. Therefore, after the electrode substrate 8 on which the dense conductive polymer layer 10 is formed is immersed in or applied to a solution containing either the conductive polymer monomer or the oxidizing agent, the other component is subsequently applied. The porous conductive polymer layer 11 is formed on the conductive polymer layer 10 by allowing the polymerization to proceed on the surface of the dense conductive polymer layer 10, such as by immersing or coating in a dissolved solution. It is desirable to make it. Further, a method of performing polymerization by immersing in a solution containing an oxidant or applying the solution and then exposing it to the vapor of the monomer can also be suitably used.

An electrolytic polymerization method can also be used to form the porous conductive polymer layer 11. At this time, the electropolymerization can be performed directly on the dense conductive polymer layer 10.
Alternatively, a separately prepared porous conductive polymer film may be placed on the conductive polymer layer 10 and additionally bonded to the conductive polymer layer 10 by polymerization.
In addition, when the electropolymerization is performed in the presence of separately prepared conductive polymer particles, the conductive polymer layer 11 having a porous structure can be formed in a shorter time.

Since the conductive polymer layer 11 is desirably in a porous state having a larger surface area, the solution containing the monomer of the conductive polymer than the method of applying and forming a film from the solution dissolved as described above. A method in which the monomer is chemically oxidatively polymerized in a state where the electrode substrate 8 on which the dense conductive polymer layer 10 is formed is in contact with the electrode substrate 8 is preferable. Furthermore, the electrochemical oxidative polymerization method (electrolytic polymerization method) can electrically control the polymerization of the conductive polymer in a room temperature air atmosphere, so that the patterning property, productivity, cost, etc. From the viewpoint, the electrolytic polymerization method is particularly preferably used.
The material and conditions of the chemical polymerization method or the electrolytic polymerization method employed in forming the porous conductive polymer layer 11 can be selected according to the materials and conditions described in the conductive polymer layer 9 described above.

  In forming the porous conductive polymer layer 11, as an oxidizing agent used in the chemical polymerization method, iodine, bromine, bromine iodide, chlorine dioxide, iodic acid, periodic acid, chlorous acid and other halides, Metal halides such as antimony pentafluoride, phosphorus pentachloride, phosphorus pentafluoride, aluminum chloride, molybdenum chloride, permanganate, dichromate, chromic anhydride, ferric salt, cupric salt, etc. High-valent metal salts, protonic acids such as sulfuric acid, nitric acid, trifluoromethanesulfuric acid, oxygen compounds such as sulfur trioxide, nitrogen dioxide, peroxo acids such as hydrogen peroxide, ammonium persulfate, sodium perborate, or salts thereof, or molybdoline There are heteropolyacids such as acid, tungstophosphoric acid, tungstomolybdophosphoric acid or salts thereof, and at least one of these can be used. .

  In forming the porous conductive polymer layer 11, the electropolymerization solvent used in the electropolymerization method can dissolve the conductive polymer monomer and be stable even at the electropolymerization potential of the conductive polymer monomer. For example, nitriles such as water and acetonitrile, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, carbonates such as propylene carbonate, tetrahydrofuran, and the like can be used. These may be used alone or as a mixed solvent of two or more. Of the above, organic solvents having a certain degree of polarity, such as acetonitrile, methanol, propylene carbonate, tetrahydrofuran and the like, can be suitably used. Furthermore, when adding a dopant, it is desirable that the dopant can also be dissolved.

  Examples of the dopant include hexafluoroline, hexafluoroarsenic, hexafluoroantimony, tetrafluoroboron, halide anions such as perchloric acid, halogen anions such as iodine, bromine, and chlorine, hexafluoroline, hexafluoroarsenic, hexafluoroantimony, Halogenated anions such as tetrafluoroboron and perchloric acid, alkyl group-substituted organic sulfonic acid anions such as methanesulfonic acid and dodecylsulfonic acid, cyclic sulfonic acid anions such as camphorsulfonic acid, benzenesulfonic acid, paratoluenesulfonic acid, dodecyl Alkyl group substituted or unsubstituted benzene mono- or disulfonic acid anion such as benzenesulfonic acid and benzenedisulfonic acid, 1 to 3 sulfonic acid groups such as 2-naphthalenesulfonic acid and 1,7-naphthalenedisulfonic acid Alkyl group-substituted or unsubstituted naphthalene sulfonate anion, anthracene sulfonate, anthraquinone sulfonate, alkyl biphenyl sulfonate, biphenyl disulfonate, etc., alkyl group-substituted or unsubstituted biphenyl sulfonate, polystyrene sulfonate, sulfonated poly High molecular sulfonate anions such as ether, sulfonated polyester, sulfonated polyimide, naphthalene sulfonate formalin condensate, boron compound anions such as substituted or unsubstituted aromatic sulfonate anions, bissaltylate boron and biscatecholate boron Or heteropoly acid anions such as molybdophosphoric acid, tungstophosphoric acid, tungstomolybdophosphoric acid, and the like. These dopants may be used alone or in combination of two or more.

（式（５）〜（８）中、Ｒ¹〜Ｒ²はそれぞれ独立に水素原子、炭素原子数１から１５のアルキル基、アルコキシ基、炭素原子数６〜１２のアリール基（例えばフェニル、トリル、ナフチルなど）、シアノ基、チオシアノ基、ヒドロキシル基、ハロゲン基、又はニトロ基を示し、Ｒ¹とＲ²はそれぞれ連結して環を形成していてもよい。）In order to suppress the desorption of the dopant, the dopant is preferably an organic acid anion rather than an inorganic anion, and is preferably one that is less susceptible to thermal decomposition.
As a dopant of the porous conductive polymer layer 11 which is an active part of the electrode, a low molecular sulfonate anion having 1 to 3 sulfonic acid groups among the above dopants may be used in order to develop porosity. desirable. Examples of such a low molecular sulfonic acid include a substituted or unsubstituted sulfonic acid group having 1 to 3 substituted naphthalenesulfonic acid anions, or a substituted or unsubstituted benzenesulfonic acid anion.
For example, it is particularly desirable to contain as a dopant at least one selected from the group consisting of benzenesulfonic acid represented by the following general formulas (5) to (8), naphthalenesulfonic acid compounds, and salts thereof.

(In the formulas (5) to (8), R ^{1 to} R ² are each independently a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, an alkoxy group, or an aryl group having 6 to 12 carbon atoms (for example, phenyl, tolyl). , Naphthyl, etc.), cyano group, thiocyano group, hydroxyl group, halogen group, or nitro group, and R ¹ and R ² may be linked to form a ring.)

As the dopant, iodine anions and / or polyiodide anions can also be preferably used.
For example, iodine anion (I ⁻ ) can be provided by using LiI, HI or the like as a dopant. The polyiodide anion is in the form of, for example, I ₃ ⁻ or I ₅ ⁻ and can be provided by dissolving and coexisting iodine (I ₂ ) and I ⁻ .

As the electropolymerization conditions, the current collector is immersed in an electropolymerization solution in which the conductive polymer monomer is dissolved in advance, and an arbitrary voltage is applied between the counter electrode placed in the same electrolysis solution. Polymerization proceeds. The conductive polymer monomer concentration at this time is not particularly limited because the optimum value varies depending on the type of the conductive polymer monomer, but generally a range of 0.01 mol / L to 10 mol / L is appropriate. A range of 0.05 to 3 mol / L is often used. In the case of coexisting a dopant, the concentration of the dopant is suitably in the range of 1/10 to 100 times the conductive polymer monomer concentration, and often in the range of 1/3 to 20 times. . The applied current density at the time of polymerization is not particularly limited because the optimum value varies depending on the type of conductive polymer monomer, but a range of 0.01 mA / cm ^{2 to} 100 mA / cm ² is appropriate, many range for 1mA / cm ² ~10mA / cm ² is used.

The thickness of the porous conductive polymer layer 11 is suitably about 5 nm to 5 μm, more preferably about 0.1 μm to 3 μm.
In the catalyst electrode having a structure of three or more layers in which the dense conductive polymer layer 10 and the porous conductive polymer layer 11 are formed on the electrode substrate 8, the specific surface area of the porous conductive polymer layer 11 is: is not particularly limited since the optimum value varies depending on the monomer used, usually at 0.1 m ² / g or more N ₂ BET specific surface area, more preferably it is suitably more than 5 m ² / g, further 10 m ² / g or more is desirable.

In this way, the conductive polymer layer 9 is formed on the electrode substrate 8 as the current collector / support to obtain a catalyst electrode, or the electrode substrate 8 as the current collector / support is densely formed. The conductive polymer layer 10 and the porous conductive polymer layer 11 are formed to obtain a porous catalyst electrode.
After preparing each component material of the dye-sensitized solar cell as described above, the metal oxide semiconductor electrode and the catalyst electrode are assembled to face each other through an electrolyte by a conventionally known method, and dye sensitization is performed. Type solar cells.

As an embodiment of the dye-sensitized solar cell of the present invention, there is an integrated dye-sensitized solar cell in which two or more unit cells are integrated.
That is, as a further embodiment of the present invention, two or more semiconductor electrodes are disposed to face one catalyst electrode via the electrolyte layer, and at least a portion facing the semiconductor electrode in the catalyst electrode. There is a dye-sensitized solar cell in which a conductive polymer layer is present. FIG. 4 is a bird's-eye view schematically showing an embodiment of the integrated dye-sensitized solar cell of the present invention, in which a plurality of semiconductor electrodes 21 are arranged to face one catalyst electrode 22. Each semiconductor electrode 21 may be arranged to face the catalyst electrode 22 via a separate electrolyte layer. At this time, the electrolyte layer may have a size corresponding to each semiconductor electrode.
In addition, the catalyst electrode 22 may include a conductive polymer layer as a whole on the electrode substrate, or may include a conductive polymer layer in a portion facing the semiconductor electrode.
In such an integrated dye-sensitized solar cell, individual unit cells (semiconductor electrode-containing cells) on the catalyst electrode 22 can be arbitrarily connected by a required voltage or the like.
The method for selectively forming the conductive polymer layer on an arbitrary portion of the electrode substrate is not particularly limited, and a known method can be used. For example, a method of performing electropolymerization after masking, or a method of controlling the shape of the counter electrode so that a conductive polymer layer is selectively formed at an arbitrary portion can be mentioned.
The size, shape, assembly method, arrangement method, number, wiring method, and the like of the above unit cells can be appropriately selected according to the desired power.

EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited at all by these.
[Example 1]
[Porous metal oxide semiconductor]
As a transparent substrate with a transparent conductive film, FTO glass (Japanese plate glass 25 mm × 50 mm) was used, and a titanium dioxide paste (Soralonix) was applied to the surface with a bar coater, dried and baked at 450 ° C. for 30 minutes. The porous titanium oxide semiconductor electrode having a thickness of 10 μm was formed by being allowed to stand at room temperature.

[Adsorption of sensitizing dye]
As a sensitizing dye, a bis (4,4′-dicarboxy-2,2′-bipyridine) diisothiocyanate ruthenium complex generally called N3dye was used. The porous titanium oxide semiconductor electrode once heated to 150 ° C. was immersed in an ethanol solution having a pigment concentration of 0.5 mmol / L, and left standing under light shielding overnight. Thereafter, excess pigment was washed with ethanol and then air-dried to produce a semiconductor electrode of a solar cell. Furthermore, the semiconductor layer was ground so that the projected area of titanium oxide of the obtained semiconductor electrode was 25 mm ² .

[Production of catalyst electrode]
As an electrode substrate with a conductive film layer, FTO glass (Nippon Sheet Glass 25 mm × 50 mm) was used. The electrode substrate ultrasonically cleaned in an organic solvent is immersed in an aqueous solution containing aniline 0.1 mol / L and hydrochloric acid 1 mol / L, and electrochemically oxidized to form a polyaniline film on the FTO glass surface. It was. This FTO glass with a polyaniline film was washed with pure water and dried in air at 100 ° C. to obtain a catalyst electrode.

[Assembly of solar cells]
The semiconductor electrode and the catalyst electrode produced as described above were placed so as to face each other, and an electrolyte was impregnated between both electrodes by capillary action. As the electrolyte, a solution containing methoxyacetonyl as a solvent, lithium iodide as a reducing agent, iodine as an oxidizing agent, t-butylpyridine as an additive, and 1,2-dimethyl-3-propylimidazolium iodide was used.

[Measurement of photoelectric conversion characteristics of solar cells]
The above solar cell is irradiated with pseudo-sunlight with an amount of light of 100 mW / cm ² to open voltage (hereinafter abbreviated as “Voc”), short-circuit current density (hereinafter abbreviated as “Jsc”), and shape. When the factors (hereinafter abbreviated as “FF”) and photoelectric conversion efficiency were evaluated, the following results were obtained.
About each measured value of "Voc", "Jsc", "FF", and a photoelectric conversion efficiency, it represents that a larger value is preferable as a performance of a photovoltaic cell.

[Measurement results of Example 1]
Open-circuit voltage (Voc): 0.69V
Short circuit current density (Jsc): 11.0 mA / cm ²
Form factor (FF): 79%
Photoelectric conversion efficiency: 6.0%

[Example 2]
In the same manner as in Example 1, except that, in the method for producing a catalyst electrode, a solar cell was produced and evaluated using aniline 0.05 mol / L, anisidine 0.05 mol / L and a dopant p-toluenesulfonic acid. .
[Measurement results of Example 2]
Open-circuit voltage (Voc): 0.74V
Short circuit current density (Jsc): 11.8 mA / cm ²
Form factor (FF): 81%
Photoelectric conversion efficiency: 7.1%

Example 3
In the same manner as in Example 1, except that in the method for producing a catalyst electrode, a solar battery cell was produced and evaluated using 2,7-naphthalenedisulfonic acid as a dopant. The formed conductive polymer layer had a thickness of about 1.2 μm and a specific surface area of about 23 m ² / g.
[Measurement results of Example 3]
Open circuit voltage (Voc): 0.71V
Short-circuit current density (Jsc): 11.6 mA / cm ²
Form factor (FF): 76%
Photoelectric conversion efficiency: 6.3%

Example 4
In the same manner as in Example 1, except that, in the method for producing a catalyst electrode, a solar cell was produced using aniline 0.05 mol / L, nitroaniline 0.05 mol / L, and a dopant p-toluenesulfonic acid, evaluated.
[Measurement results of Example 4]
Open-circuit voltage (Voc): 0.73V
Short circuit current density (Jsc): 9.5 mA / cm ²
Form factor (FF): 72%
Photoelectric conversion efficiency: 5.0%

Example 5
In the same manner as in Example 1, except that in the method for producing a catalyst electrode, a solar battery cell was produced and evaluated using hydriodic acid as a dopant. The film thickness of the formed conductive polymer layer was about 1.0 μm.
[Measurement results of Example 5]
Open-circuit voltage (Voc): 0.74V
Short circuit current density (Jsc): 11.5 mA / cm ²
Form factor (FF): 82%
Photoelectric conversion efficiency: 7.0%

Example 6
In the same manner as in Example 1, except that in the method for producing the catalyst electrode, the monomer is 3,4-ethylenedioxythiophene 0.05 mol / L, the dopant is p-toluenesulfonic acid 0.1 mol / L, and the solar cell is formed. Prepared and evaluated. The film thickness of the formed conductive polymer layer was about 0.6 μm.
[Measurement results of Example 6]
Open-circuit voltage (Voc): 0.74V
Short circuit current density (Jsc): 10.1 mA / cm ²
Form factor (FF): 69%
Photoelectric conversion efficiency: 5.2%

Example 7
In the same manner as in Example 1, except that the catalyst electrode was produced as follows, and a solar battery cell was produced and evaluated.
In the catalyst electrode, FTO glass was used for the electrode substrate. As the conductive polymer, poly (3,4-ethylenedioxythiophene) / polystyrene sulfonic acid aqueous dispersion (hereinafter referred to as PEDOT / PSS liquid) (manufactured by Aldrich) was used. First, after filtering the PEDOT / PSS solution, spin-coating on FTO glass under the condition of 1000 rpm × 30 seconds, air-drying, and then heat-drying at 90 ° C. for 15 minutes for 5 times to conduct the conductive polymer A layer was formed. The thickness of the conductive polymer layer was about 0.5 μm.
[Measurement results of Example 7]
Open-circuit voltage (Voc): 0.69V
Short circuit current density (Jsc): 9.1 mA / cm ²
Form factor (FF): 58%
Photoelectric conversion efficiency: 3.6%

Example 8
After impregnating FTO-coated glass as an electrode substrate in an aqueous solution in which 0.1 mol / L of pyrrole and 100 g / L of polyvinyl sulfonic acid are dissolved, electrolytic polymerization is performed to form a dense conductive polymer layer. It was. The black polypyrrole film formed on the FTO glass surface was washed and dried at 100 ° C. for 15 minutes. The film thickness of the polymerized dense polypyrrole was about 0.5 μm.

The obtained FTO glass with polypyrrole was taken out after being immersed in a hydrogen peroxide solution in which p-toluenesulfonic acid was dissolved at 0.1 mol / l, and then exposed to pyrrole vapor. A porous polypyrrole layer was formed on the polypyrrole to obtain a porous catalyst electrode. The film thickness of the polymerized porous polypyrrole was about 1 μm, and the specific surface area was about 16 m ² / g.

When the produced porous catalyst electrode was observed with a digital microscope from the electrode substrate side, the conductive polymer film was peeled off or no unpolymerized cloudy part was observed, and the polypyrrole film was adhered to the entire surface in black. It was confirmed.
[Measurement results of Example 8]
Open-circuit voltage (Voc): 0.69V
Short-circuit current density (Jsc): 10.2 mA / cm ²
Form factor (FF): 72%
Photoelectric conversion efficiency: 5.1%

Example 9
In the method for producing the catalyst electrode, FTO glass (Nippon Sheet Glass 25 mm × 50 mm) was used as the electrode substrate with the conductive film layer. The electrode substrate cleaned ultrasonically in an organic solvent is coated with tris (butanol solution in which iron salt of paratoluenesulfonic acid is dissolved) as an oxidizing agent, and then exposed to pyrrole vapor to form a porous polypyrrole layer. The film thickness of the polymerized porous polypyrrole was about 1.5 μm.
When the FTO glass formed only by the obtained porous polypyrrole layer was observed in the same manner as in Example 8, only 75% of the electrode area was adhered to the polypyrrole.
Using this catalyst electrode, a solar battery cell was assembled in the same manner as in Example 1 and evaluated in the same manner as in Example 1.
[Measurement results of Example 9]
Open circuit voltage (Voc): 0.62V
Short-circuit current density (Jsc): 8.2 mA / cm ²
Form factor (FF): 81%
Photoelectric conversion efficiency: 4.1%

Example 10
Ammonium persulfate was dropped into an ice bathed sulfuric acid aqueous solution having an aniline concentration of 0.1 mol / l to polymerize aniline to obtain polyaniline particles. Ammonia water was allowed to act on the obtained polyaniline particles, and then dissolved in N-methylpyrrolidone (hereinafter abbreviated as NMP) so that the polyaniline was 20% by mass to obtain a polyaniline NMP solution.
An FTO-coated glass (25 mm × 50 mm) serving as an electrode substrate was dipped in the polyaniline NMP solution, then pulled up and dried by heating in air at 150 ° C. for 1 hour to obtain a dense polyaniline-coated FTO glass.
The resulting polyaniline-coated FTO glass was doped with p-toluenesulfonic acid. The film thickness of the dense polyaniline formed was about 0.8 μm.

Further, the polyaniline-coated FTO glass subjected to the dope treatment is used as a working electrode, and platinum is used as a counter electrode, and aniline is electropolymerized in an aqueous solution containing aniline 0.1 mol / l and p-toluenesulfonic acid 1 mol / l. A porous polyaniline coating was applied. After the electropolymerization, the porous catalyst electrode was obtained by washing with distilled water and drying in air at 100 ° C. for 15 minutes. The obtained porous polyaniline had a film thickness of about 1.5 μm and a specific surface area of about 28 m ² / g.
As a result of observing the surface of the electrolytic polymerization portion with a scanning electron microscope, the porous catalyst electrode was confirmed to be in a porous state.

Using the semiconductor electrode and the porous catalyst electrode produced as described above, solar cells were assembled in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are as follows.
[Measurement results of Example 10]
Open-circuit voltage (Voc): 0.72V
Short circuit current density (Jsc): 11.8 mA / cm ²
Form factor (FF): 76%
Photoelectric conversion efficiency: 6.5%

Example 11
In the same manner as in Example 10, a dense polyaniline film was formed with a polyaniline NMP solution to prepare a doped polyaniline-coated FTO glass, but a catalyst electrode was obtained without forming the subsequent porous polyaniline layer. .
Using this catalyst electrode, a solar battery cell was assembled in the same manner as in Example 1 and evaluated in the same manner as in Example 1. At this time, the film thickness was 0.4 μm, and the specific surface area was about 2 m ² / g. The results are as follows.
[Measurement results of Example 11]
Open-circuit voltage (Voc): 0.74V
Short circuit current density (Jsc): 9.1 mA / cm ²
Form factor (FF): 62%
Photoelectric conversion efficiency: 4.2%

Example 12
In the same manner as in Example 1, except that in the method for producing the catalyst electrode, the catalyst electrode was produced with polyvinyl sulfonic acid as the dopant and the conductive polymer layer having a film thickness of 4 μm, and evaluation was performed by assembling solar cells.
[Measurement results of Example 12]
Open-circuit voltage (Voc): 0.72V
Short circuit current density (Jsc): 9.3 mA / cm ²
Form factor (FF): 59%
Photoelectric conversion efficiency: 4.0%

[Comparative Example 1]
Except for the production method of the catalyst electrode, solar cells were produced and evaluated in the same manner as in Example 1.
In the catalyst electrode, FTO glass was used for the electrode substrate. A platinum layer was formed on the FTO glass by sputtering. The thickness of the platinum layer was about 150 nm.
[Measurement results of Comparative Example 1]
Open circuit voltage (Voc): 0.67V
Short-circuit current density (Jsc): 8.9 mA / cm ²
Form factor (FF): 64%
Photoelectric conversion efficiency: 3.8%

  Table 1 below shows the materials, forming methods, and measured values of the conductive polymer films of the above examples. The parentheses in the material column represent the dopant.

*1 比表面積：約23ｍ²/ｇ
*2 比表面積：約16ｍ²/ｇ
*3 比表面積：約28ｍ²/ｇ
*4 比表面積：約２ｍ²/ｇ

* 1 Specific surface area: about 23m ² / g
* 2 Specific surface area: Approximately 16m ² / g
* 3 Specific surface area: about 28m ² / g
* 4 Specific surface area: about 2m ² / g

  From the above results, it can be seen that the dye-sensitized solar cell provided with the catalyst electrode of the present invention has excellent photoelectric conversion efficiency.

  ADVANTAGE OF THE INVENTION According to this invention, the catalyst electrode for dye-sensitized solar cells which can reduce | restore rapidly the oxidation body of the oxidation reduction pair contained in electrolyte is provided. Furthermore, this catalyst electrode is disposed opposite to a semiconductor electrode containing a dye having a photosensitizing action through an electrolyte layer, thereby providing a dye-sensitized solar having excellent photoelectric conversion efficiency and excellent durability. A battery can be provided.

It is a cross-sectional schematic diagram which shows an example of a structure of the dye-sensitized solar cell of this invention. It is a cross-sectional schematic diagram which shows an example of a structure of the catalyst electrode of this invention. It is a cross-sectional schematic diagram which shows an example of a structure of the catalyst electrode of this invention. It is a bird's-eye view which shows an example of a structure of the dye-sensitized solar cell of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrode base body 2 Transparent substrate 3 Transparent conductive film 4 Porous metal oxide semiconductor layer 5 Sensitizing dye layer 6 Electrolyte layer 7 Catalyst electrode 8 Electrode base 9 Conductive polymer layer 10 Dense conductive polymer layer 11 Porous conductivity Polymer layer 21 Semiconductor electrode 22 Catalyst electrode

Claims (16)

  In a dye-sensitized solar cell having a light-transmitting semiconductor electrode containing a dye having a photosensitizing action and an electrolyte layer containing a chemical species serving as a redox pair, the semiconductor electrode faces the semiconductor electrode through the electrolyte layer. A catalyst electrode to be disposed, comprising a conductive polymer layer on an electrode substrate, wherein the conductive polymer layer contains iodine anions and / or polyiodide anions as dopants. Catalytic electrode. The conductive polymer is represented by an aromatic amine compound represented by the following general formula (1) or (2), a thiophene compound represented by the following general formula (3), and the following general formula (4). The catalyst electrode according to claim 1, which is a polymer formed by polymerizing at least one monomer selected from the group consisting of pyrrole compounds.

(In the formula (1) or (2), R ₁ and R ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and R _{2 to} R ₅ and R _{7 to} R ₁₀ each independently represent a hydrogen atom or carbon. An alkyl group or an alkoxy group having 1 to 8 atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, a halogen group, a nitro group, an amino group, an amide group, A hydroxyl group, a thiol group, a carboxyl group, a sulfo group, or a phosphonium group, and in formula (1), R ₂ and R ₃ , or R ₄ and R ₅ may be linked to form a ring, In formula (2), R ₈ and R ₉ , or R ₉ and R ₁₀ may be linked to form a ring.)

(In Formula (3), R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an alkoxy group, an aryl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, and a halogen group. Nitro group, amino group, carboxyl group, sulfo group, or phosphonium group, and R ₁₁ and R ₁₂ may be linked to form a ring.)

(In Formula (4), R <_13> , R <_14> is respectively independently a hydrogen atom, a C1-C8 alkyl group or an alkoxy group, a C6-C12 aryl group, a cyano group, a thiocyano group, and a halogen group. Nitro group, amino group, carboxyl group, sulfo group, or phosphonium group, and R ₁₃ and R ₁₄ may be linked to form a ring.)   The catalyst electrode according to claim 1 or 2, wherein the conductive polymer is a polymer formed by polymerizing at least aniline as a monomer. The catalyst electrode according to claim 2 , wherein the conductive polymer is a copolymer comprising aniline and at least one selected from the aromatic amine compounds represented by the general formula (1) or (2) as monomers.   The aromatic amine compound represented by the general formula (1) or (2) is aniline, anisidine, phenetidine, toluidine, phenylenediamine, hydroxyaniline, N-methylaniline, trifluoromethaneaniline, nitroaniline, cyanoaniline and halogenated. The catalyst electrode according to claim 2 or 4, which is selected from aniline.   The catalyst electrode according to claim 2, wherein the conductive polymer is a polymer formed by polymerizing at least a thiophene compound represented by the general formula (3) as a monomer.   The catalyst electrode according to claim 6, wherein the conductive polymer is a polymer formed by polymerizing at least 3,4-ethylenedioxythiophene as a monomer.   The conductive polymer is a polymer formed by polymerizing at least one selected from the group consisting of pyrrole, 3-methylpyrrole, 3-butylpyrrole and 3-octylpyrrole as a monomer. The catalyst electrode as described. The conductive polymer layer contains, as a dopant, at least one selected from the group consisting of benzenesulfonic acid represented by the following general formulas (5) to (8), naphthalenesulfonic acid compounds, and salts thereof. The catalyst electrode according to any one of claims 1 to 8.

(In the formulas (5) to (8), R ^{1 to} R ² each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a cyano group, a thiocyano group, a hydroxyl group, a halogen group, or a nitro group, R ¹ and R ² may be linked to each other to form a ring.) 10. The catalyst electrode according to claim 1, wherein the conductive polymer layer has a specific surface area of 5 m ² / g or more.   The thickness of a conductive polymer layer is 5 nm-5 micrometers, The catalyst electrode of any one of Claims 1-10 characterized by the above-mentioned.   The catalyst electrode according to any one of claims 1 to 11, wherein the conductive polymer layer is formed on the electrode substrate by electrochemical polymerization.   In a dye-sensitized solar cell having a light-transmitting semiconductor electrode containing a dye having a photosensitizing action and an electrolyte layer containing a chemical species serving as a redox pair, the semiconductor electrode faces the semiconductor electrode through the electrolyte layer. A porous catalyst electrode to be disposed, having a conductive polymer layer formed by densely polymerizing a monomer that forms a conductive polymer on the surface of the electrode substrate, on the conductive polymer layer, A porous catalyst electrode having a porous conductive polymer layer obtained by polymerizing a monomer that forms a conductive polymer as an active part of the electrode. An aromatic amine compound represented by the general formula (1) or (2), wherein the monomer for forming the conductive polymer layer formed by dense polymerization and the monomer for forming the porous conductive polymer layer are each independently The porous catalyst electrode according to claim 13, selected from the group consisting of: a thiophene compound represented by the general formula (3), a pyrrole compound represented by the general formula (4), furan, pyridine, and benzene.

(In the formula (1) or (2), R ₁ and R ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and R _{2 to} R ₅ and R _{7 to} R ₁₀ each independently represent a hydrogen atom or carbon. An alkyl group or an alkoxy group having 1 to 8 atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, a halogen group, a nitro group, an amino group, an amide group, A hydroxyl group, a thiol group, a carboxyl group, a sulfo group, or a phosphonium group, and in formula (1), R ₂ and R ₃ , or R ₄ and R ₅ may be linked to form a ring, In formula (2), R ₈ and R ₉ , or R ₉ and R ₁₀ may be linked to form a ring.)

(In Formula (3), R ₁₁ and R ₁₂ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an alkoxy group, an aryl group having 6 to 12 carbon atoms, a cyano group, a thiocyano group, and a halogen group. Nitro group, amino group, carboxyl group, sulfo group, or phosphonium group, and R ₁₁ and R ₁₂ may be linked to form a ring.)

(In Formula (4), R <_13> , R <_14> is respectively independently a hydrogen atom, a C1-C8 alkyl group or an alkoxy group, a C6-C12 aryl group, a cyano group, a thiocyano group, and a halogen group. , A nitro group, an amino group, a carboxyl group, a sulfo group, or a phosphonium group, R ₁₃ and R ₁₄ may be linked to form a ring.   In a dye-sensitized solar cell having a light-transmitting semiconductor electrode containing a dye having a photosensitizing action and an electrolyte layer containing a chemical species serving as a redox pair, the semiconductor electrode faces the semiconductor electrode through the electrolyte layer. A method for producing a porous catalyst electrode to be disposed, comprising: (a) forming a conductive polymer layer on a surface of an electrode substrate by densely polymerizing a monomer that forms a conductive polymer; and b) producing a porous catalyst electrode comprising a step of forming a porous conductive polymer layer obtained by polymerizing a monomer that forms a conductive polymer on the conductive polymer layer as an active part of the electrode; Method. At least a light-transmitting semiconductor electrode containing a dye having a photosensitizing action, an electrolyte layer containing at least a chemical species serving as a redox pair, and a catalyst electrode disposed opposite to the semiconductor electrode via the electrolyte layer A dye-sensitized solar cell comprising the catalyst electrode according to any one of claims 1 to 12 or the porous catalyst electrode according to claim 13 or 14. .

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