JP2007179907A - Power generator, power generation method, and power generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power generator capable of effectively generating electric power from hydrogen and oxygen, or accumulating protons and electrons by a visible light responding photocatalyst by utilizing the visible light irradiated from a light source. <P>SOLUTION: The power generator, generating electric power from hydrogen and oxygen by utilizing the visible light irradiated from a light source, is provided with a first electrode 10, a proton conducting part 20, a second electrode 30, an electron accumulation part 40, a proton accumulation part 50, and a switch 60. The first electrode is electrically connected to the second electrode through an electron accumulation part, and a switch connecting the first electrode to the second electrode in this sequence from first electrode side. The first electrode contains a first conductive material, the visible light responding photocatalyst, and an electric charge separating material, and the second electrode contains a second conductive material and a metallic material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power generation apparatus, a power generation method, and a power generation system, and more specifically, generates electricity from a hydrogen source containing a compound containing hydrogen as a constituent element and oxygen using visible light emitted from a light source. The present invention relates to a power generation device that can be stored as protons and electrons, a power generation method using the power generation device, and a power generation system including the power generation device.

In recent years, there are concerns about the problem of gas discharged from mobile objects and the depletion of fuel resources.
Therefore, in recent years, research and development of fuel cells using hydrogen (H ₂ ) and oxygen (O ₂ ) as fuels have been conducted.
However, there are many problems regarding how hydrogen (H ₂ ) as a fuel is manufactured and how it is mounted on a moving body.

As a solution to this problem, a direct methanol fuel cell has been proposed in which methanol is mounted and methanol is directly decomposed at the electrode and used in the form of protons (see Patent Document 1).
A single cell of this fuel cell (hereinafter referred to as “fuel cell”) has a structure in which an electrolyte layer made of special plastic is sandwiched between two electrodes from the left and right.
JP 2004-71311 A

Further, in this fuel cell, when hydrogen (H ₂ ) as a fuel is supplied to one electrode, that is, the fuel electrode side, hydrogen (H ₂ ) is protonated by the catalytic action of the electrode, and this proton is converted into an electrolyte. It reaches the other electrode, that is, the air electrode side through the layer.

Since oxygen, which is an oxidant, is supplied to the air electrode side, protons meet and react with oxygen there to produce water.
During this reaction, since electrons constantly move from the fuel electrode side to the air electrode side, a current flows through the circuit.
Thus, the fuel cell generates electric power.

On the other hand, along with research on fuel cells, research on dye-sensitized solar cells has been conducted as an effective use of sunlight.
This dye-sensitized solar cell is mainly composed of a pair of transparent substrates, a transparent conductive film constituting a pair of electrodes, a semiconductor layer which is a photoelectric conversion material sandwiched between the electrodes, and a carrier transport layer. . The semiconductor layer has adsorbed on its surface a sensitizing dye having an absorption spectrum in the visible light region.

In such a solar cell, when the semiconductor layer is irradiated with visible light, the sensitizing dye on the surface of the semiconductor layer absorbs light, thereby exciting the electrons in the dye molecule and injecting the excited electrons into the semiconductor layer. .
The electrons injected into the semiconductor layer move from one electrode to the other electrode through an electric circuit.
The electrons that have moved to the other electrode are carried by holes or ions in the carrier transport layer and return to the semiconductor layer.
Such processes are repeated to extract electric energy.

Specifically, a solar cell in which a sensitizing dye such as a ruthenium complex is adsorbed has been proposed (see Patent Documents 2 and 3).
Japanese Patent Laid-Open No. 1-220380 International Publication No. WO91 / 16719

However, the technique described in Patent Document 1 has a problem that noble metal (Pt) is used in the electrodes of the fuel electrode and the air electrode, and the problem of CO poisoning also occurs in the fuel electrode.
In addition, an additional membrane must be added to prevent methanol from passing through the proton conducting membrane.

On the other hand, in the techniques described in Patent Documents 2 and 3, since the solar cell cannot sufficiently separate the charge generated between the electrons and holes generated by the dye efficiently and the recombination of electrons and holes occurs, the conversion efficiency of the solar cell is increased. Is only about 10%.
Moreover, since a ruthenium complex is used, it becomes expensive, the manufacturing method is complicated, and it is difficult to spread industrially.
Furthermore, there is a problem that the amount of power generation greatly fluctuates corresponding to the amount of light irradiation from sunlight, and it becomes impossible to generate power especially when it is not exposed to light.

The present invention has been made in view of such problems of the prior art, and the object of the present invention is to use visible light responsive photocatalytic material using visible light irradiated from a light source. A power generation apparatus capable of efficiently generating electricity from a hydrogen source including a compound having a constituent element and oxygen or storing them as protons (H ⁺ ) and electrons (e ⁻ ), a power generation method using the power generation apparatus, and An object is to provide a power generation system using a power generation device.

As a result of intensive studies to achieve the above object, the inventor brought a hydrogen source containing a compound having hydrogen (H) as a constituent element into contact with a visible light responsive photocatalytic material, and obtained visible light from a light source. irradiating the said visible light responsive photocatalyst material, a hydrogen source and a proton (H ⁺⁾ electrons ^- generate, resulting protons (H ⁺⁾ of the flow and electron (e) ^- control the flow of (e) The inventors have found that the above-described object can be achieved by reacting these with oxygen (O ₂ ) and controlling the amount of power generation, and the present invention has been completed.

That is, the power generation device of the present invention is a power generation device that generates power from a hydrogen source containing a compound having hydrogen (H) as a constituent element and oxygen using visible light irradiated from a light source.
Such a power generation device includes a first electrode, a proton conduction unit, a second electrode, an electron accumulation unit, a proton accumulation unit, and a switch, and the proton conduction unit includes the first electrode and the second electrode. And the first electrode and the second electrode from the first electrode side, the electron storage unit, the first electrode, and the second electrode. The switches that can electrically connect two electrodes are electrically connected in this order, and the first electrode includes a first electrically conductive material, a visible light responsive photocatalytic material, and a charge separation material. The second electrode contains a second electrically conductive material and a metal material.

The power generation method of the present invention is a power generation method using the power generation device of the present invention, wherein a hydrogen source containing a compound having hydrogen (H) as a constituent element and a visible light responsive photocatalytic material are brought into contact with each other. The visible light responsive photocatalytic material is irradiated with visible light from a light source to generate protons (H ⁺ ) and electrons (e ⁻ ) from the hydrogen source, and the resulting proton (H ⁺ ) flow and electrons (e ^- ) The flow of) is controlled to react with oxygen (O ₂ ) to control the power generation amount.

  Furthermore, the power generation system of the present invention is a power generation system using the above-described power generation device of the present invention, the power generation device and supply means for supplying a hydrogen source containing a compound having hydrogen as a constituent element to the power generation device. A supply means for supplying oxygen to the power generation apparatus, a discharge means for discharging oxygen from the power generation apparatus, a discharge means for discharging water from the power generation apparatus, and a compound having hydrogen as a constituent element for the power generation apparatus Control means for controlling the supply amount of the hydrogen source, control means for controlling the supply amount of oxygen to the power generation apparatus, control means for controlling the discharge amount of water from the power generation apparatus, and Control means for controlling the amount of oxygen discharged, control means for controlling the amount of visible light emitted from the light source to the power generation apparatus, and control means for controlling the on / off state of the switch of the power generation apparatus. , Turn on the switch Off state control means, and performing control of intermittently the switch on and off.

According to the present invention, a hydrogen source containing a compound having hydrogen (H) as a constituent element is brought into contact with a visible light responsive photocatalyst material, the visible light responsive photocatalyst material is irradiated with visible light from a light source, Protons (H ⁺ ) and electrons (e ⁻ ) are generated from a hydrogen source, and the resulting proton (H ⁺ ) and electron (e ⁻ ) flows are controlled to react with oxygen (O ₂ ). Because the amount of power generation is controlled, the visible light responsive photocatalyst material is utilized by the visible light responsive photocatalyst material using the visible light emitted from the light source, and the efficiency from the hydrogen source and oxygen containing the compound having hydrogen (H) as a constituent element. It is possible to provide a power generation device that can generate electricity well or store it as protons (H ⁺ ) and electrons (e ⁻ ), a power generation method using the power generation device, and a power generation system using the power generation device.

Hereinafter, the power generator of the present invention will be described in detail.
As described above, the power generator of the present invention is a power generator that generates electricity from a hydrogen source containing a compound having hydrogen (H) as a constituent element and oxygen using visible light emitted from a light source. A first electrode, a proton conducting part, a second electrode, an electron accumulating part, a proton accumulating part, and a switch, the proton conducting part being sandwiched between the first electrode and the second electrode. And the first electrode and the second electrode are electrically connected from the first electrode side to the first electrode and the second electrode. The obtained switches are electrically connected through this order.

  The first electrode contains a first electrically conductive material, a visible light responsive photocatalytic material, and a charge separation material, and the second electrode contains a second electrically conductive material and a metal material.

By adopting such a configuration, the visible light responsive photocatalyst material is activated by the visible light irradiated from the light source, and the hydrogen source containing the compound having hydrogen (H) as a constituent element is used as the visible light responsive photocatalyst. When the switch is in an on state, electricity can be generated efficiently. When the switch is in an off state, electrons (e ⁻ ) In addition, protons (H ⁺ ) can be accumulated in the proton accumulation unit.

  Further, when the switch is turned on from the accumulated state, electricity can be generated even when light is not irradiated from the light source.

Furthermore, as described above, when storing electricity, it can be stored in the state of electrons (e ⁻ ) and protons (H ⁺ ). Therefore, when a system is constructed, it is not necessarily a nickel metal hydride battery or a lithium ion battery. A power storage device is not required, and the power storage device can be downsized even when the power storage device is provided.

Moreover, the energy source utilized when obtaining electricity from a hydrogen source is reduced more than before.
Specifically, it is not always necessary to apply electricity from an external power source to generate electricity, and the power generator can be further downsized.
Furthermore, since it is not always necessary to use an expensive semiconductor thin film and it is not always necessary to use a ruthenium complex, it can be designed to be inexpensive and durable. It becomes easy to mount on a moving body.

In the present invention, a current detector may be provided between the first electrode and the electron storage unit.
Such a current detector can measure the amount of electricity generated when the switch is on, and can roughly measure the amount of electrons stored in the electron storage section when the switch is off. Can be guessed.
And electricity can be more efficiently generated by performing control of a power generator based on such a measured value or an estimated value.

Furthermore, in the present invention, a photodetector may be provided.
Here, the photodetector is a so-called optical sensor that detects visible light irradiated from the light source to the power generation device, more preferably the first electrode, and more preferably the visible light responsive photocatalytic material, and the irradiation amount. There is no particular limitation as long as it can be measured, and for example, a photodiode or the like can be used.
And electricity can be more efficiently generated by performing control of a power generator based on the measured value of such a photodetector.

Here, the electric power generating apparatus of this invention is demonstrated in detail using drawing.
FIG. 1 is a schematic diagram illustrating an example of a power generator according to the present invention. As shown in the figure, the power generator 1 includes a first electrode 10, a proton conducting unit 20, a second electrode 30, an electron accumulating unit 40, a proton accumulating unit 50, a switch 60, and a current detector 70. And a photodetector 80.
The proton conducting unit 20 is sandwiched between the first electrode 10 and the second electrode 30 and further joined to the proton accumulating unit 50.
Further, the first electrode 10 and the second electrode 30 are switches 60 that can electrically connect the current detector 70, the electron storage unit 40, and the first electrode 10 and the second electrode 30 from the first electrode 10 side. And are connected by a wiring w.
FIG. 1 shows a case where the switch 60 is in an off state.

The visible light responsive photocatalyst material (not shown) contained in the first electrode 10 is activated by the visible light irradiated from the light source by irradiating visible light from the light source as indicated by an arrow a. However, by supplying water (H ₂ O), which is an example of a hydrogen source, to the visible light-responsive photocatalytic material as shown by an arrow b, the electrons (e ⁻ ) (not shown) are formed in the first electrode 10. ), Proton (H ⁺ ) (not shown), and oxygen (O ₂ ) as indicated by an arrow c, and the obtained electrons (e ⁻ ) pass through the current detector 70 and pass through the electron storage unit 40. On the other hand, the obtained proton (H ⁺ ) passes through the proton conducting part 20 and is accumulated in the proton accumulating part 50.
Further, FIG. 1 does not show a case where the switch 60 is in an ON state, but in that case, for example, oxygen (O ₂ ) in the air is supplied as shown by a dashed arrow d, and the second Water (H ₂ O) is generated from the electrode 30 as indicated by a dashed arrow e. Details will be described later.

In addition, in the present invention, the electron storage section provided is not particularly limited as long as it can store electrons (e ⁻ ), but the material and shape thereof are not particularly limited, but a polymer, metal or metal oxide, and any of these It is desirable that the electron storage material includes a combination of the above and an insulating material, and the electron storage material is covered with the insulating material.
The electronic structure of the electron storage material is preferably conductive so that electrons can be stored and flow easily.

The polymer as the electron storage material is not particularly limited, and examples thereof include conductive polymers such as doped polyaniline, polypyrrole, and polythiophene.
The metal that is an electron storage material is not particularly limited, and examples thereof include copper (Cu), iron (Fe), manganese (Mn), and nickel (Ni).
Furthermore, the metal oxide that is an electron storage material is not particularly limited, and examples thereof include tungsten trioxide (WO ₃ ), nickel oxide (NiO), copper oxide (CuO), and the like. It is desirable to use WO ₃ from the viewpoints of properties and electron storage capacity.

  The insulating material is not particularly limited, but is preferably an insulating polymer such as polycarbonate or polyethylene terephthalate from the viewpoint of light weight, free design of shape, and transparency. Can be used.

FIG. 2 shows a schematic cross-sectional shape of an example of an electron storage unit provided in the power generation device of the present invention. As shown in the figure, the electron storage section 40 has a structure in which WO ₃ which is an example of the electron storage material 42 is covered with an insulating polymer which is an example of an insulating material 44 such as polycarbonate.
Note that the electron storage material 42 is electrically connected to a first electrode and a switch (not shown) by a wiring w.

Furthermore, in the present invention, the material and shape of the proton accumulating portion provided is not particularly limited as long as it can accumulate protons (H ⁺ ), but it is not limited to solid polymer, glass or metal oxide, and these It is desirable that the proton storage material according to any combination of the above and a proton efflux prevention material have a structure covered with the proton loss prevention material.

The solid polymer that is the proton storage material is not particularly limited, and examples thereof include a proton conductive membrane such as Nafion (registered trademark, manufactured by DuPont).
Further, the glass that is a proton storage material is not particularly limited, and examples thereof include a proton conducting membrane such as phosphate glass.
Furthermore, the metal oxide that is a proton storage material is not particularly limited, and examples thereof include tungsten trioxide (WO ₃ ), nickel oxide (NiO), copper oxide (CuO), and the like. It is desirable to use WO ₃ from the viewpoints of properties and proton accumulation capacity.

  The proton efflux prevention material is not particularly limited, but from the viewpoint of being lightweight, freely designing the shape, and being transparent, for example, a proton efflux prevention polymer such as polycarbonate or polyethylene terephthalate is used. It can be used suitably.

Here, it is desirable that the electron storage unit and the proton storage unit provided have a capacitor structure from the viewpoint of increasing the amount of electrons (e ⁻ ) and protons (H ⁺ ) stored.
For example, the capacitor structure may be constructed by the structure of the power generation device itself, or the capacitor structure may be constructed by arranging a plurality of power generation devices when constructing the power generation system.

Furthermore, a configuration of an example of a switch provided in the power generation device of the present invention will be described. FIG. 3 is an explanatory diagram showing a schematic cross-sectional shape of an example of a switch configured using an FET. As shown in the figure, a channel 62, a source 63, a drain 64, an insulator layer 65, and a gate 66 are formed on a substrate 61, and the portions other than the insulator layer 65 are made of a conductor.
Either an inorganic semiconductor or an organic semiconductor FET may be used, and a MOSFET that is an inorganic semiconductor functions as follows.
After applying a positive voltage to the gate 66, electrons in the P-type silicon are attracted to the bottom of the insulator layer 65 across the insulator layer 65, and a narrow path made of electrons is formed between the drain 64 and the source 63. It is formed. Then, this becomes a path of current, and conduction is established between the drain 64 and the source 63. When the application of voltage is stopped, conduction between the drain 64 and the source 63 stops. An organic semiconductor FET typified by pentacene operates in the same manner although there are differences in constituent materials.

  The FET switch source 63 and drain 64 are connected to the output wiring of the electron storage section (not shown) and the wiring to the second electric conduction material, respectively, and the signal wiring from an external control device (not shown) is used as the gate. It can be joined and used as a switch.

Next, the electronic state and the flow of electrons (e ⁻ ) in the power generator of the present invention will be described.
Electrons (e ⁻ ) generated in the first electrode 10 move to the electron storage unit 40 and further move to the second electrode 30, while protons (H ⁺ ) generated in the first electrode 10 are transferred to the proton conducting unit 20. To the second electrode 30.

Further, as described above, in order to make the flow of electrons (e ⁻ ) and protons (H ⁺ ), particularly the flow of electrons (e ⁻ ) smooth, and to improve the power generation efficiency, the first electrode 10, the electron storage. It is desirable that the electronic states in the part 40 and the second electrode 30 satisfy the following relations [1] and [2] when the heights of energy levels between components in each part are compared ( For details, refer to FIGS.

[1] (Upper end of valence band of visible light responsive photocatalyst material) <(Earth energy level of ground state capable of plasma absorption of fine particles exhibiting plasmon absorption in charge separation material and light absorption of dye)
[2] (Lower end of conduction band of visible light responsive photocatalytic material)> (Energy level of excited state by plasma absorption of fine particles exhibiting plasmon absorption in charge separation material and excited state at light absorption of dye)> (No. 1 Electrically conductive material (for metal material: Fermi level, for semiconductor: lower end of conduction band)) ≧ (electron accumulating part (for metal material: Fermi level, for semiconductor: lower end of conduction band)) ≧ (Second electrically conductive material (for metal material: Fermi level, for semiconductor: lower end of conduction band))> (Fermi level of metal material of second electrode)

When the above relationship is established, the electrons (e ⁻ ) flow roughly in the following two ways.
That is, electrons generated by the visible light responsive photocatalyst material (e ^-) electrons are generated by the visible light responsive photocatalyst material and when flowing from through a charge separation material on the first electrically conductive material (e ^-) is first May flow directly into electrically conductive material.

First, in the above-described case, the visible light responsive photocatalyst material is irradiated with visible light, so that holes (holes) generated in the visible light responsive photocatalyst material, further electrons (e ⁻ ) and protons (H ⁺ ) are generated. The mechanism of generating electricity by the flow will be explained.

Each of the visible light responsive photocatalyst material and the charge separation material can be used alone or in combination.
At this time, in order to prevent recombination of electrons (e ⁻ ) and holes (holes) generated by light absorption in the visible light responsive photocatalytic material, the band gap of the visible light responsive photocatalytic material and the charge separation material It is desirable to adjust the band gap (transition energy).
In other words, the potential (electron band energy level) for emitting electrons (e ⁻ ) in the visible light responsive photocatalytic material is the potential at which the electrons (e ⁻ ) enter holes formed in the charge separation material (plasma can be absorbed). The energy level of the excited state due to the plasma absorption of the charge separation material and the excited state during the light absorption of the dye is higher than the ground state and the energy level of the dye when absorbing the light. It is desirable that the bandgap (transition energy) of the charge separation material is lower than the bandgap of the visible light responsive photocatalytic material.

FIG. 9 is a graph showing an example of an absorption spectrum of the visible light responsive photocatalyst material and the charge separation material having a preferable relationship as described above.
In addition, as shown in FIG. 9, the charge separation material itself exhibits plasmon absorption.

FIG. 4 shows a first electrode (visible light responsive photocatalyst material, charge separation material, and first electric conductive material), an electron storage unit, and a second electrode (second electric conductive material) having a preferable relationship as described above. It is explanatory drawing which shows an example of the electronic state and the flow of an electron and a hole in (metal material).
As shown in FIG. 4, in the first electrode, the visible light responsive photocatalytic material is irradiated with visible light, the electrons (e ⁻ ) are excited, and excited electrons (e ⁻ ) and holes (holes) are generated.

At this time, for example, when water (H ₂ O) (not shown) as an example of a hydrogen source comes into contact with the visible light responsive photocatalyst, the water (H ₂ O) receives a hole and oxygen (O ₂ ) is appear.
In addition, the electrons (e ⁻ ) generated in the visible light responsive photocatalytic material enter the ground state in which the charge separation material can absorb the plasma and the ground state in the light absorption of the dye. The electrons (e ⁻ ) generated in the charge separation material move to the first electrically conductive material. Alternatively, the electrons (e ⁻ ) generated in the visible light-responsive photocatalytic material move to the first electrically conductive material directly via the excited state of plasma absorption and the excited state of the dye.
Furthermore, the electrons (e ⁻ ) moved to the first electrically conductive material move to the electron storage unit.
When the switch is on, the electrons (e ⁻ ) move to the second electrode. On the other hand, when the switch is off, electrons (e ⁻ ) are accumulated in the electron accumulation unit.

Furthermore, protons (H ⁺ ) generated from water (H ₂ O) move to the proton conducting part.
When the switch is on, this proton (H ⁺ ) moves to the second electrode. On the other hand, when the switch is off, protons (H ⁺ ) are accumulated in the proton accumulation unit.

  As a result, the reaction represented by the following formula (1) occurs in the first electrode.

2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ (1)

In the second electrode, the reaction represented by the following formula (2) occurs due to protons, electrons, and oxygen, and water (H ₂ O) is generated.

O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O (2)

  As a result, electricity can be generated by the power generator.

In the case described later, the contained charge separation material is not used, but it goes without saying that it is included in the scope of the present invention. Specifically, as described above, in the first electrode, visible light responsive photocatalytic material is irradiated with visible light, electrons (e ⁻ ) are excited, and excited electrons (e ⁻ ) and holes (holes) are generated. Generate.
At this time, for example, when water (H ₂ O), which is an example of a hydrogen source, comes into contact with the visible light responsive photocatalyst, the water (H ₂ O) receives holes and generates oxygen (O ₂ ). .
Moreover, the electrons (e ⁻ ) generated in the visible light responsive photocatalytic material move to the first electrically conductive material. Thereafter, electrons (e ⁻ ) and protons (H ⁺ ) are accumulated according to the flow of electrons (e ⁻ ) and protons (H ⁺ ) as in the case described above. Electricity is generated and water (H ₂ O) is generated.

5 to 8, electrons can flow from the first electrode toward the second electrode as in the case of FIG. 4.
However, the flow of electrons differs depending on what kind of material (material having a different electronic structure) is selected for the charge separation material, the first electrically conductive material, the electron storage portion, and the second electrically conductive material.

The flow of electrons will be described in more detail with respect to the energy levels of the charge separation material, the first electrically conductive material (conductive glass), and the electron storage portion (in the case of a semiconductor such as a conductive polymer or tungsten trioxide (WO ₃ )). .
The electrons emitted from the charge separation material move to the conduction band of the first electrically conductive material. Next, when the switch is in the on state, the electrons once move to the conduction band of the electron storage unit and move to the second electrode.

When the switch is off, electrons can be stored in the electron storage section up to an energy level corresponding to the energy level at the lower end of the conduction band of the first electrically conductive material.
Further, when the switch is turned on from the off state, the electrons flow toward the second electrode.

Next, the structure of the first electrode will be described.
As long as the reaction of the above formula (1) proceeds, the first electrode can contain the three components of the first electric conductive material, the visible light responsive photocatalytic material, and the charge separation material in various modes.

For example, as shown in FIG. 10, it can be composed of a single layer 11 in which a first electrically conductive material, a visible light responsive photocatalytic material, and a charge separation material are mixed and dispersed.
At this time, the three components can be uniformly dispersed. Further, a large amount of the first electrically conductive material can be included on the proton conductive portion side, and a large amount of visible light responsive photocatalytic material can be included on the surface layer side (layer in contact with the hydrogen source).

Further, as shown in FIG. 11, the first layer 12 and the second layer 13 can be sequentially stacked on the proton conducting portion.
In this case, it is preferable that the first layer 12 is made of the first electrically conductive material, and the second layer 13 is made by mixing and dispersing the visible light responsive photocatalytic material and the charge separation material.
Note that one end of the wiring (not shown) is preferably connected to a layer (first layer) in contact with the proton conducting portion.

  Furthermore, as shown in FIG. 12, the first to third layers (12 to 14) may be sequentially stacked on the proton conducting portion.

For example, all of the first to third layers (12 to 14) are composed of a first electrically conductive material, a visible light responsive photocatalytic material, and a charge separation material, and the main component of the first layer 12 is the first electrically conductive material. The main component of the second layer 13 can be a charge separation material, and the main component of the third layer 14 can be a visible light responsive photocatalytic material.
Note that the “main component” is a layer containing three or more components of the first electric conductive material, the visible light responsive photocatalytic material, and the charge separation material as long as it is 1/3 or more of the total content. If so, it means to occupy 1/2 or more of their total content.

  The first layer 12 is made of a first electroconductive material, a visible light responsive photocatalytic material, and a charge separation material, the main component is the first electroconductive material, and the second layer 13 is electrolyzed with the visible light responsive photocatalytic material. It is also possible to make it composed of a separation material, the main component is a charge separation material, the third layer 14 is composed of a visible light responsive photocatalyst material and a charge separation material, and the main component is a visible light responsive photocatalyst material. .

Further, the first layer 12 may be made of a first electrically conductive material, the second layer 13 may be made of a charge separation material, and the third layer 14 may be made of a visible light responsive photocatalytic material.
The charge separation material is placed between the visible light responsive photocatalytic material and the first electrically conductive material so that the visible light responsive photocatalytic material is in contact with the hydrogen source, and the first electrically conductive material is in contact with the proton conducting portion. It is desirable to arrange in such a manner from the viewpoint of power generation efficiency. From such a viewpoint, in particular, the first layer 12 is made of the first electrically conductive material, the second layer 13 is made of the charge separation material, and the third layer 14 is made. Is preferably made of a visible light responsive photocatalytic material.

Hereinafter, the description will be divided into a carbon system and a conductive glass system.
Here, when the first electrode of the single layer is manufactured, for example, the slurry in which the first electrically conductive material, the visible light responsive photocatalyst material, and the charge separation material are mixed is dried to obtain the first single layer first electrode. Although an electrode can be obtained, it is not limited to this.

Further, when the first electrode having the above two-layer structure is manufactured, it is not particularly limited. For example, a conductive carbon cloth or a conductive carbon porous material slurry is applied to a conductive carbon cloth and dried. Then, a first layer is formed by pressing, and a slurry containing a visible light-responsive photocatalytic material and a charge separation material is applied on the first layer and dried to form a second layer. One electrode can be obtained.
At this time, the visible light responsive photocatalytic material and the charge separation material can be applied uniformly or non-uniformly.

Further, when the first electrode having the above three-layer structure is manufactured, it is not particularly limited. However, after applying each material, drying treatment, press treatment, and heat treatment may be appropriately performed as follows.
For example, a conductive carbon cloth or a conductive carbon porous material slurry is applied to a conductive carbon cloth, dried to form a first layer, a slurry containing a charge separation material is applied thereon, and a second layer is formed. A layer is formed, and a slurry containing a visible light responsive photocatalytic material is applied thereon to form a third layer, and the whole is heated to obtain a first electrode having a three-layer structure.

  Also, a conductive carbon cloth or conductive carbon porous material slurry is applied to the conductive carbon cloth, dried, pressed to form a first layer, and a slurry containing a charge separation material is applied thereon, A second layer is formed by drying, and a slurry containing a visible light responsive photocatalytic material is applied thereon, dried and heat-treated to form a third layer, and a first electrode having a three-layer structure is formed. Obtainable.

  Furthermore, the conductive carbon cloth is coated with a slurry of conductive carbon particles or a conductive carbon porous body, dried, pressed to form a first layer, and a slurry containing a charge separation material is coated thereon and dried. Then, a second layer is formed, and further, a slurry containing a visible light responsive photocatalytic material is applied thereon and dried to form a third layer, whereby a first electrode having a three-layer structure can be obtained. .

  In addition, although the said drying process is not specifically limited, For example, it can carry out at 120-200 degreeC and about 1 to 2 hours. Moreover, although the said press process is not specifically limited, For example, it can carry out at about 0.1-40 Mpa. Furthermore, although the said heat processing is not specifically limited, For example, it can carry out at 400-1200 degreeC and about 2 to 20 hours.

Hereinafter, a case where the first electrically conductive material of the first electrode includes one or more kinds selected from fibrous or porous conductive glass coated with ITO, FTO, CuI, or ZnO will be described.
Also in this case, it can be manufactured in substantially the same manner as the conductive carbon cloth, the conductive carbon particles, or the conductive carbon porous body. However, since conductive glass is relatively brittle, it is better not to include a pressing step.

For example, it can be produced as follows.
When manufacturing the single-layer first electrode, for example, a slurry in which the first electrically conductive material, the visible light-responsive photocatalytic material, and the charge separation material are mixed is dried to obtain the single-layer first electrode. However, the present invention is not limited to this.

  When the first electrode having a two-layer structure is manufactured, it is not particularly limited. For example, a fibrous or porous conductive glass slurry is applied and dried to form the first layer. On this, a slurry containing a visible light responsive photocatalytic material and a charge separation material is applied and dried to form a second layer, whereby a first electrode having a two-layer structure can be obtained.

  A slurry of a fibrous or porous conductive glass is applied, a slurry containing a charge separation material is applied thereon, dried to form a second layer, and a visible light responsive photocatalytic material is further formed thereon. A third layer can be formed by applying a slurry containing and dried to obtain a first electrode having a three-layer structure.

Next, the structure of the second electrode will be described.
In the second electrode, as long as the reaction of the above formula (2) proceeds, the two components of the second electrically conductive material and the metal material can be contained in various modes.

For example, as shown in FIG. 13, it can be composed of a single layer 31 in which a second electrically conductive material and a metal material are mixed and dispersed.
At this time, the two components can be uniformly dispersed. Further, a large amount of the second electrically conductive material can be included on the proton conductive portion side, and a large amount of a metal material can be included on the back layer side (a layer in contact with air (oxygen)).

Further, as shown in FIG. 14, the first layer 32 and the second layer 33 may be sequentially stacked on the proton conducting portion.
For example, the main component of the first layer 32 can be a second electrically conductive material, and the main component of the second layer 33 can be a metal material.
Note that one end of the wiring (not shown) is preferably connected to a layer (first layer) in contact with the proton conducting portion.

Further, the first layer 32 may be made of a second electrically conductive material, and the second layer 33 may be made of a metal material.
From the viewpoint of power generation efficiency, it is desirable to dispose the metal material away from the proton conducting portion so that the second electrically conductive material is in contact with the proton conducting portion. It is desirable that the second layer 33 is made of a metal material and is made of two electrically conductive materials.

  Here, when manufacturing the single-layer second electrode, there is no particular limitation. For example, a slurry containing a metal material and a second electrically conductive material is dried to form a single-layer second electrode. Can be obtained.

  In addition, when the second electrode having the two-layer structure is manufactured, there is no particular limitation. For example, the conductive carbon cloth is coated with a slurry of conductive carbon particles or a conductive carbon porous body and dried. Then, a first layer is formed by pressing, a slurry containing metal fine particles is applied thereon, and dried to form a second layer, and the whole is heat-treated to obtain a second electrode having a two-layer structure. be able to.

  Furthermore, a conductive carbon cloth or a conductive carbon porous material slurry is applied to a conductive carbon cloth, dried, pressed to form a first layer, and metal fine particles are applied thereon and dried. A second layer can be formed to obtain a second electrode having a two-layer structure.

  On the other hand, the joining of the first electrode, the proton conducting portion, and the second electrode can be performed, for example, by disposing the proton conducting portion between the first electrode and the second electrode, and pressing with a press. it can. In this case, for example, it can be performed at about 0.1 to 40 MPa.

Next, components of the first electrode will be described.
As described above, in the present invention, the first electrode provided includes the first electrically conductive material, the visible light responsive photocatalytic material, and the charge separation material.

The visible light-responsive photocatalytic material has a function of generating protons (H ⁺ ) from a hydrogen source containing a compound having hydrogen (H) as a constituent element by irradiation with visible light, preferably as a hydrogen source generate water _(H 2 O) from the proton ^{(H +),} but as the oxygen _{(O 2)} is not particularly limited if Sonaere the ability to produce results, for example, five nitride three tantalum _(Ta 3 N ₅ ) A photocatalyst, a tantalum oxynitride (TaON) photocatalyst, a photocatalyst obtained by doping titanium oxide (TiO ₂ ) with chromium (Cr) and antimony (Sb), and the like.
Furthermore, what contains the compound as described in the following [1]-[7] individually or in mixture can be mentioned.

[1] Oxynitride containing a transition metal according to La, Ta, Nb, Ti or Zr and any combination thereof [2] Tritantalum pentanitride (Ta ₃ N ₅ )
[3] Strontium-titanium oxide (SrTiO ₃ ), silver-tantalum oxide (AgTaO ₃ ), silver-niobium oxide (AgNbO ₃ ), indium-tantalum oxide (InTaO ₄ ), indium-niobium oxide (InNbO ₄ ), metal oxides doped with bismuth-vanadium oxide (BiVO ₄ ), or nitrogen (N), sulfur (S), chromium (Cr) or antimony (Sb), and any combination thereof. [4] ZnS doped with zinc sulfide (ZnS), copper (Cu) and / or nickel (Ni)
[5] Gallium (Ga) oxide, Indium (In) oxide, Zinc (Zn) oxide, Silver (Ag) oxide, Sodium (Na) oxide [6] Ga sulfide, In sulfide, Zn sulfide things, Ag sulfide, Na sulfide [7] gallium oxide - indium oxide solid solution _{(Ga 2 O 3 -In 2 O} 3)

The visible light responsive photocatalytic material is preferably composed of fine particles having an average diameter of 0.01 to 50 μm.
This is effective because holes generated in the photocatalyst are more likely to react with a hydrogen source (for example, water).

In addition, an ultraviolet light-responsive photocatalyst material can be used together with the visible light-responsive photocatalyst material. For example, titanium oxide (TiO ₂ ), alkali tantalate, alkaline earth tantalate, alkaline niobate, alkaline earth niobate, zinc niobate, and the like can be given.

The charge separation material is preferably a visible light responsive photocatalyst and a photocatalyst having the function of separating and moving electrons (e ⁻ ) and holes (holes) generated in the visible light responsive photocatalyst material. Although it is not particularly limited as long as it has a function of separating and moving electrons (e ⁻ ) and holes (holes) generated in the charge separation material itself, for example, fine particles exhibiting plasmon absorption and visible light region Mention may be made of those containing one or both of the dyes exhibiting absorption.
The visible light responsive photocatalyst material at present is limited to a visible light wavelength range of 380 to 550 nm, and in particular, a charge separation material exhibiting plasmon absorption is preferable from the viewpoint that the wavelength range of visible light that can be absorbed can be expanded. Since the absorption wavelength of plasmon absorption varies depending on the constituent elements and the size of the fine particles, it can be appropriately selected as necessary.
In addition, since the absorption wavelength similarly varies depending on the molecular structure and size, the dye can be appropriately selected as necessary.

Further, by adding fullerene to the charge separation material, the function of separating and moving electrons (e ⁻ ) and holes (holes) can be further improved.
Examples of the fullerene include C ₆₀ , C ₇₀ , C ₇₆ , C ₇₈ , C ₈₂ , C ₈₄ , C ₉₀ , C _{96, and the} like, and a metal atom is appropriately included in the fullerene. You can also
For example, the energy gap between the conduction band and the valence band in the case of C ₆₀ is as small as 1.2 eV. Therefore, it is easy to receive electrons from a photocatalyst having a large energy gap.

As the fine particles exhibiting plasmon absorption, for example, gold (Au), silver (Ag), platinum (Pt), and an alloy according to any combination thereof can be used.
These can be nano-sized rod-shaped, spherical one or both shapes. In particular, Au nanorods are effective.

  From the visible light responsive photocatalyst material side to the plasmon fine particles and the first electrical conductive material, the visible light responsive photocatalyst material side is charged to the first electrical conductive material so that the generated electrons can easily flow. It is best to grade the energy levels of the electron and conduction bands. That is, the first electrode is formed by sequentially laminating a layer containing the first electrically conductive material, a layer containing the charge separation material, and a layer containing the visible light responsive photocatalytic material on the proton conducting portion. As the transition from the layer containing the visible light responsive photocatalytic material to the layer containing the first electrical conductive material has a structure, the energy level at the lower end of the conduction band of the band structure of each material in the layer It is desirable that the energy level at the upper end of the valence band of the band structure of each material becomes lower and the energy level becomes higher. For example, FIG. 15 shows a structure of a layer containing plasmon fine particles and a preferred embodiment of its electronic structure change.

This is due to the following reason.
In the plasmon fine particle, the absorption spectrum changes depending on the size and shape. For example, a gold spherical nanoparticle has a plasmon absorption peak of about 530 nm in the range of 2 to 50 nm.
In the case of gold nanorods, the major axis of the rod is in the range of 10 to 100 nm and the minor axis is 5 to 50 nm, the plasmon absorption peak position is 530 nm with respect to the minor axis, and the plasmon absorption peak position is 820 nm with respect to the major axis. .
From this, it is possible to smoothly connect to the electronic state of the first electrically conductive material by joining the plasmon fine particles of the above size (the electronic structure of the layer structure including the plasmon fine particles in FIG. 15). Change). By connecting smoothly, the electron trajectory which comprises each part can be mixed strongly, and it becomes easy to move an electron.
In addition, it can be expected that electrons are accelerated and flow easily by a strong electric field generated by plasmon resonance.
As a result, electrons generated in the visible light responsive photocatalyst material can smoothly move to the first electrically conductive material without flowing back to the visible light responsive photocatalyst material, and can move to the second electrode. It can be improved.
If necessary, plasmon absorption peak positions change from 420 to 530 nm by preparing plasmon fine particles made of an alloy in which the ratio of silver (plasmon absorption peak position 420 nm) and gold (plasmon absorption peak position 530 nm) is changed. As a result, the energy level gradient can be controlled more finely.

  Moreover, as a pigment | dye which shows absorption of visible region, the thing concerning a porphyrin compound, its metal complex, a phthalocyanine compound or its metal complex, and these arbitrary combinations can be used, for example. In particular, when several to about 10 connected porphyrins are used, the electron movement in the major axis direction can be selectively promoted by the resonance effect.

FIG. 16 is a schematic view showing an example of the structure of a layer containing a dye and its electronic structure change diagram. As shown in the figure, when the dye molecule is organic, the visible light responsive photocatalyst material may decompose this organic dye, so it is bonded to the dye molecule with respect to the visible light responsive photocatalyst material. On the other hand, it is desirable to coat a dye protecting material having a lower catalytic activity than the visible light responsive photocatalytic material. For example, a structure including a layer containing a dye protective material between a layer containing a visible light responsive photocatalyst material and a layer containing a dye exhibiting absorption in the visible light region may be employed.
As such a dye protective material, the coating of an oxide semiconductor (Ta ₂ O ₅ , Ti ₂ O ₃ , WO ₃ or the like) is the best. This prevents the photocatalyst from coming into direct contact with the organic dye. Further, in order to facilitate the flow of electrons, the valence band and the energy level of the conduction band are graded from the visible light responsive photocatalyst material side to the first electrically conductive material.

Further, as described above, fine particles exhibiting plasmon absorption or dyes exhibiting absorption in the visible light region are preferable as the charge separation material. However, since the above-described fullerene functions effectively as an electron (e ⁻ ) acceptor, it absorbs plasmon absorption. It is desirable to further add fullerene to the fine particles to be displayed and the dye exhibiting absorption in the visible light region. As described above, when the charge separation material containing fullerenes is disposed so as to be bonded to the fine particles exhibiting plasmon absorption or the dye exhibiting absorption in the visible light region, electrons flow smoothly without backflow. Details will be described below.
FIG. 17 is a schematic view showing an example of a structure in which C ₆₀ is contained in a layer containing plasmon fine particles and its electronic structure change diagram. Fullerene has an energy level smoothly connected to a smooth energy level curve of a layer containing fine particles exhibiting plasmon absorption, and the band energy gap is further reduced. Furthermore, it leads smoothly to the energy level of the first electrically conductive material. Therefore, electrons flow smoothly without backflow.

As the first electrically conductive material, in order to take electrons in the conduction band of the charge separating material into the first electrically conducting material, the charge separating material needs to be well bonded. Therefore, it is not particularly limited as long as it shows good conductivity. For example, it is possible to use conductive carbon particles, a conductive carbon porous body or a conductive carbon cloth, and any combination thereof. it can.
Further, the conductive carbon particles and the conductive carbon porous body have an advantage that they are excellent in electrical conductivity, and are fine particles, so that various materials can be easily carried. Specific examples include carbon black and carbon nanotubes.
On the other hand, as the conductive carbon cloth, one made of a fibrous carbon fiber excellent in conductivity can be suitably used.

However, in order to improve the electron storage performance, the first electrically conductive material of the first electrode is at least one selected from a fibrous or porous conductive glass in which the conductive glass is coated with ITO, FTO, CuI or ZnO. Use of a seed-containing material is desirable for storing electrons.
This is because, as described above, as the first electrically conductive material, it is necessary to secure an accumulation amount of electrons and an accumulation voltage in the electron accumulation portion.
Furthermore, the same material as the first electrically conductive material can be used as the second electrically conductive material in the second electrode described later. However, the second electrically conductive material does not necessarily need to be conductive glass.
Needless to say, the first electrically conductive material and the second electrically conductive material may be the same or different.

Next, the components of the proton conducting part will be described.
As described above, in the present invention, the proton conducting portion provided is not particularly limited as long as it exhibits almost no electron conductivity and good proton conductivity. For example, either one of a polymer and an oxide is used. Or it is desirable that it is a proton conductive membrane containing both.
For example, it is desirable to use Nafion (registered trademark, manufactured by DuPont) having high proton conductivity. Other polymer proton conducting membranes and proton conducting glasses can also be used. For example, there is phosphate glass which is proton conductive glass.

Next, the components of the second electrode will be described.
As described above, in the present invention, the second electrode provided includes the second electrically conductive material and the metal material.

As the metal material, for example, Pt, NiO, Ru ₂ O or IrO ₂ and any combination thereof can be used, and Pt is particularly desirable. Further, it is desirable that these shapes are fine particles or tubes.
As the second electrically conductive material, the same material as the first electrically conductive material can be used as described above.

In the present invention, as the light source, a solar light source, a light emitting diode, a semiconductor laser, a lamp capable of emitting visible light equivalent to these, and a combination thereof can be used as appropriate.
In particular, from the viewpoint of excellent energy conversion efficiency, it is desirable to use a light emitting diode that enables light emission in a very narrow visible region.
Moreover, as long as the sun is shining, the sunlight which is not depleted and can be used may be used directly, or may be collected and collected.
Further, visible light may be spectrally separated by a prism.

Furthermore, in the present invention, the hydrogen source containing the compound having hydrogen as a constituent element is not particularly limited. For example, alcohol such as methanol or ethanol can be used as appropriate, but water or a sacrificial reagent can be used. It is particularly desirable to use a containing aqueous solution.
By using water as a hydrogen source, there is an advantage that the problem of exhaust gas can be completely solved.

The sacrificial reagent contained in the sacrificial reagent-containing aqueous solution includes compounds capable of generating hydroxide ions (OH ⁻ ), sulfite ions (SO ₃ ²⁻ ), and ions related to any combination thereof in water. Is preferably included.
When such oxidizable substances are present in the solution, they react with the holes generated when the visible light-responsive photocatalytic material is in an excited state, so that the generated electrons (e ⁻ ) recombine with the holes. This reduces the probability of power generation and facilitates power generation.
Typically, alcohol, potassium sulfite, or the like can be used as a sacrificial reagent.

In the present invention, it is desirable that the power generation device is disposed in a light-transmitting casing.
In the power generation device of the present invention, the first electrode requires that the visible light-responsive photocatalytic material contained therein can be irradiated with light.
In order to satisfy such requirements, for example, it is desirable to have a structure in which the power generation device itself is disposed in a light-transmitting casing.

Next, the power generation method of the present invention will be described in detail.
As described above, the power generation method according to the present invention is a power generation method using the power generation apparatus according to the present invention, in which a hydrogen source containing a compound having hydrogen (H) as a constituent element is contacted with a visible light-responsive photocatalytic material. The visible light responsive photocatalyst material is irradiated with visible light from a light source to generate protons (H ⁺ ) and electrons (e ⁻ ) from the hydrogen source, and the resulting proton (H ⁺ ) flow and electrons This is a method of controlling the power generation amount by controlling the flow of (e ⁻ ) and reacting these with, for example, oxygen (O ₂ ) in air.
By such a method, a visible light responsive photocatalyst material is activated by visible light irradiated from a light source, and a hydrogen source containing a compound having hydrogen (H) as a constituent element is brought into contact with the visible light responsive photocatalyst material. Therefore, electricity can be generated efficiently, or electrons (e ⁻ ) and protons (H ⁺ ) can be accumulated, respectively.
Moreover, even when light is not irradiated from the light source from the accumulated state, more specifically, electricity can be generated according to the irradiation amount from the visible light source.

Next, the power generation system of the present invention will be described in detail.
As described above, the power generation system according to the present invention is a power generation system using the power generation apparatus according to the present invention, and supplies the power generation apparatus and a hydrogen source containing a compound having hydrogen as a constituent element to the power generation apparatus. Means for supplying oxygen to the power generation device, discharge means for discharging oxygen from the power generation device, discharge means for discharging water from the power generation device, and hydrogen to the power generation device as constituent elements Control means for controlling the supply amount of a hydrogen source containing a compound, control means for controlling the supply amount of oxygen to the power generation apparatus, control means for controlling the discharge amount of water from the power generation apparatus, and the power generation apparatus Control means for controlling the amount of oxygen discharged from the control apparatus, control means for controlling the irradiation amount of visible light from the light source to the power generation apparatus, control means for controlling the on / off state of the switch of the power generation apparatus, Comprising the switch Down-off state control means, in which intermittently controls the said switching on and off.
With such a configuration, it is possible to construct a power generation system that is very compact and consumes less energy.
Moreover, it becomes easy to mount in mobile bodies, such as a motor vehicle, by setting it as such a compact electric power generation system.

As the supply means for supplying the hydrogen source and oxygen, for example, a hydrogen source tank, a pressure adjusting valve, a pressure gauge, piping, a cock, an air take-off valve, and the like can be appropriately combined.
The on / off state control means is not particularly limited as long as it can control the switch of the power generation device. Specifically, the electronic control having a 16-bit microcomputer or a conventionally known arithmetic unit is possible. The apparatus can be used as appropriate.

Further, the on / off state control means calculates the integrated data of these detection data so that the detection data from the photodetector provided in the power generation device and the detection data from the current detector are input. You may be able to.
Furthermore, the on / off state control means may store therein reference data for detection data from the photodetector in advance, and may also store electron storage amount reference data and electronic data for detection data from the current detector. The limit accumulation amount of the accumulation unit may be stored in advance. At that time, it is possible to appropriately execute the control of the power generation device based on the limit accumulation amount of the reference data.

The on / off state control means may be capable of controlling a hydrogen source or oxygen supply means.
Specifically, the supply amount of the hydrogen source and air (oxygen) supplied by the hydrogen source and oxygen supply means can be controlled by the on / off state control means, for example, for opening and closing of the cock provided. Also good.

FIG. 18 is a schematic diagram showing an example of the power generation system of the present invention.
As shown in the figure, the power generation system 100 includes a power generation apparatus 1, a hydrogen source and oxygen supply unit 110, an on / off state control unit 120, and a hydrogen source and oxygen discharge unit 130.
The supply unit 110 stores water that is an example of a hydrogen source, has a cock (not shown) that feeds the water to the power generation apparatus 1, and supplies water to the power generation apparatus 1. The supply means 110 takes in air and also supplies air (oxygen) to the power generation apparatus.
The control means 120 controls the switch of the power generation device 1 by a photodetector (not shown) that determines the amount of visible light emitted from the light source, and further according to whether or not electricity is generated. When electricity is generated in the on state and electricity is not required, the switch is turned off, and the electrons (e ⁻ ) and protons (H ⁺ ) Accumulate in proton accumulation part. In addition, the control unit 120 controls the water supply amount and air supply amount to the power generation device 1, the oxygen discharge amount from the power generation device, the water discharge amount, and the sunlight irradiation amount to the power generation device.

Further, in the present invention, when the control device provided intermittently controls the switch, based on the data from the photodetector of the power generation device and the integrated calculation data from the current detector of the power generation device, It is desirable to perform control.
With such a configuration, it is possible not only to construct a power generation system that is very compact and consumes less energy, but also to improve power generation efficiency.

Further, in the present invention, a power storage device may be provided. In this case, the power storage device provided can be reduced in size, and a power generation system that is very compact and consumes less energy can be constructed.
Furthermore, for example, when the amount of electrons and protons accumulated in the electron accumulating unit and proton accumulating unit reaches a limit, electricity is generated from the electrons and protons and stored in the power storage device to further improve the power generation efficiency. be able to.
Note that the power storage device to be used is not particularly limited as long as the obtained electricity can be stored in the power storage device as needed, and a conventionally known power storage device can be used.

Furthermore, in the present invention, a visible light source may be provided. As the visible light source, for example, a light emitting diode, a semiconductor laser, a lamp that can emit visible light equivalent to these, and a combination thereof can be used as appropriate.
For example, when a power generation system is installed in an automobile, a fuel cell is usually used as another energy device. For example, when a solar light source cannot be used, the electricity generated by the fuel cell using a light emitting diode or the like is effectively used. Power generation.
In addition, you may provide the water circulation means which is a water collection | recovery means, and a system can be compactized by utilizing water again. Further, by combining with the fuel cell, specifically, the water discharged from the fuel cell can be recovered and reused as a hydrogen source, whereby the hydrogen source tank provided can be reduced in size or eliminated, and more compact. It becomes possible to construct a power generation system.

FIG. 19 is a flowchart showing an example of a control flow of the power generator of the present invention.
As shown in the figure, in STEP 1 (hereinafter abbreviated as “S1”), the control means determines whether or not it is necessary to generate power. If it is necessary (YES), the process proceeds to S2.
In S2, it is determined whether or not sunlight is sufficient by the photodetector and the control means. If it is sufficient (YES), the process proceeds to S3.
In S3, water and air (oxygen), which are a kind of hydrogen source, are supplied by the supply means and the control means.
In S4, the control means turns on the switch.
In S5, the power generation device is operated to generate electricity.

  If it is not sufficient (NO) in S2, the process proceeds to S4. Then, in S4, when the switch is turned on, when protons and electrons are stored in the proton storage unit and the electron storage unit, respectively, the operation of the power generator can be performed and electricity is generated.

If it is not necessary (NO) in S1, the process proceeds to S6.
In S6, it is determined whether the sunlight is sufficient by the photodetector and the control means. If it is sufficient (YES), the process proceeds to S7.
In S7, the switch is turned off by the control means.
In S8, water and air (oxygen), which are a kind of hydrogen source, are supplied by the supply means and the control means.
In S9, electrons and protons are stored in the electron storage unit and proton storage unit, respectively.
In S6, if it is not sufficient (NO), nothing is done.

  Hereinafter, the present invention will be described in more detail with reference to some examples.

Example 1
<Production of first electrode>
TaON was prepared as a visible light responsive photocatalyst material, gold fine particles (diameter: 20 nm) as plasmon absorption fine particles as a charge separation material, and fibrous or porous conductive glass as a first electric conductive material.
A fibrous or porous conductive glass slurry, which is a first electrically conductive material, is applied to a heat-resistant ceramic substrate, a slurry containing a charge separation material is applied thereon, and dried to form a second layer. Then, a slurry containing a visible light responsive photocatalytic material was applied thereon and dried to form a third layer, whereby a first electrode having a three-layer structure was obtained.

<Production of second electrode>
Pt fine particles were prepared as the metal material, and carbon fiber and carbon black were prepared as the second electrically conductive material.
A slurry containing a second electrically conductive material is applied to a heat-resistant ceramic substrate and dried to obtain a first layer made of the second electrically conductive material. A slurry containing a metal material is applied thereon and dried. A second layer made of a metal material was obtained, and these were peeled from the substrate to obtain a second electrode having a two-layer structure.

<Production of electron storage unit>
Copper was prepared as an electron storage material, and polycarbonate was prepared as an insulating polymer. The electron storage material was covered with an insulating polymer to obtain an electron storage portion.

<Production of proton accumulation part>
A plastic membrane made of Nafion (registered trademark, manufactured by DuPont) as a proton storage material and polycarbonate as a proton outflow prevention material was prepared. The proton storage material was covered with a plastic membrane to obtain a proton storage part.

<Construction of power generation equipment>
The first electrode, the second electrode, the electron accumulating unit, the proton accumulating unit, the proton conducting unit, a Nafion film, the wiring as a copper wire, the photodetector as a photodiode, a switch, a current detector, a light-transmitting casing A colorless and transparent glass container was prepared.
The proton conducting part 20 was sandwiched between the first electrode 10 and the second electrode 30, and these were put into a mold, pressed, and pressure-bonded and joined with a weak force. Further, the proton conducting part 20 and the proton accumulating part 50 are joined, and the first layer 12 of the first electrode 10 and a current detector (not shown) are connected by wiring (not shown) to detect the current. The device and the electron storage unit (not shown) are connected by wiring (not shown), the electron storage unit and the switch (not shown) are connected by wiring, and the switch and the second electrode 30 are further connected. The first layer 32 was connected by wiring and housed in a light transmissive casing 90 as shown in FIG. 20 to construct the power generation apparatus of this example.
FIG. 20 is a schematic configuration diagram of the power generation device according to the first embodiment. Although not shown, the current detector, the electron storage unit, and the switch are housed in the light transmissive casing 90. Further, although not shown, the photodetector is arranged so that the visible light irradiation amount at the first electrode 10 can be measured.

(Example 2)
<Production of second electrode>
A slurry containing a second electrically conductive material and a metal material is applied to a heat resistant ceramic substrate, and dried to obtain a single layer of uniform distribution composed of the second electrically conductive material and the metal material. A second electrode having a single layer structure was obtained.

<Construction of power generation equipment>
A power generator of this example was constructed by adopting the same configuration as in Example 1 except that the second electrode having a single layer structure was used instead of the second electrode having a two layer structure.

(Example 3)
<Production of first electrode>
Fullerene (C ₆₀ ) was added to gold fine particles (diameter: 20 nm), which are fine particles exhibiting plasmon absorption prepared as a charge separation material, to prepare a fullerene-containing charge separation material.
Except for using the fullerene-containing charge separation material, the same operation as in the production of the first electrode of Example 1 was repeated to obtain a first electrode.

<Construction of power generation equipment>
A power generator of this example was constructed by adopting the same configuration as in Example 1 except that the first electrode having a three-layer structure manufactured using the fullerene-containing charge separation material was used.

Example 4
<Production of proton accumulation part>
Except for using proton conductive glass as the proton storage material, the same operation as in the production of the proton storage section in Example 1 was repeated to obtain a proton storage section.

<Construction of power generation equipment>
A power generator of this example was constructed by adopting the same configuration as that of Example 1 except that the proton accumulation part produced using the proton conductive glass was used.

(Example 5)
<Production of first electrode>
A first electrode was obtained by repeating the same operation as in the production of the first electrode of Example 1, except that zinc porphyrin was used as the charge separation material and the visible light responsive photocatalytic material was coated with Ta ₂ O ₅ .

<Construction of power generation equipment>
Except for using the first electrode prepared by coating zinc porphyrin as the charge separation material and coating the visible light responsive photocatalytic material with Ta ₂ O ₅ , the same configuration as in Example 1 was adopted. A power generator was constructed.

(Example 6)
<Production of electron storage unit>
An operation similar to the production of the electron storage part in Example 1 was repeated except that a conductive polymer was used as the electron storage material to obtain an electron storage part.

<Construction of power generation equipment>
A power generator of this example was constructed by adopting the same configuration as in Example 1 except that the electron accumulating part produced using the conductive polymer was used.

(Example 7)
<Production of electron storage unit>
Except for using ZnO as the electron storage material, the same operation as in the preparation of the electron storage unit in Example 1 was repeated to obtain an electron storage unit.

<Construction of power generation equipment>
A power generator of this example was constructed by adopting the same configuration as that of Example 1 except that the electron storage unit manufactured using ZnO was used.

(Example 8)
<Production of first electrode>
Carbon fiber and carbon black were prepared as the first electrically conductive material. A slurry containing a first electrically conductive material is applied to a heat-resistant ceramic substrate and dried to obtain a first layer made of the first electrically conductive material. A slurry containing a charge separation material is applied thereon and dried. To obtain a second layer made of a charge separation material, and apply a slurry containing a visible light responsive photocatalyst material thereon, and then dry to obtain a third layer made of a visible light responsive photocatalyst, and peel them off from the substrate. Thus, a first electrode having a three-layer structure was obtained.

<Construction of power generation equipment>
A power generator of this example was constructed by adopting the same configuration as in Example 1 except that the first electrode produced using carbon fiber and carbon black was used as the first electrically conductive material.

[Performance evaluation]
Using the power generators of the above examples (see FIG. 1), water was circulated through a flow path formed in the housing, and sunlight was used as a light source to evaluate performance.
(Evaluation conditions)
・ Light source: Solar light source ・ Hydrogen source: Water ・ Accumulation time: 1 hour

As a result of the performance evaluation, the power generation apparatus of Example 1 was able to generate electricity even when it was not irradiated with sunlight.
Further, in Example 2, the amount of power generation per unit time was smaller than that in Example 1.
Furthermore, in Example 3, compared with Example 1, there was much electric power generation amount per unit time.
Moreover, in Example 4, compared with Example 1, the electric power generation amount per unit time was equivalent.
Furthermore, in Example 5, compared with Example 1, the electric power generation amount per unit time was equivalent.
Moreover, in Example 6, compared with Example 1, the electric power generation amount per unit time was a little small. Furthermore, compared with Example 1, the generated voltage was very high.
Furthermore, in Example 7, compared with Example 1, the power generation amount per unit time was slightly smaller. Furthermore, compared with Example 1, the generated voltage was very high.
Furthermore, in Example 8, compared with Example 1, the power generation amount per unit time was very small.

Example 9
FIG. 21 is a schematic diagram illustrating an example of an automobile power generation system.
As shown in the figure, an automobile power generation system was constructed using the power generation apparatus constructed in Example 1.

Specifically, in the automobile power generation system 200, the power generation apparatus 1 is mounted on the roof 210 of the automobile.
As a supply means for supplying a hydrogen source containing a compound having hydrogen as a constituent element and air, a cock (not shown) for flowing water in a hydrogen source tank 220 attached to the roof 210 into the power generation apparatus 1. And the pipe | tube (not shown) which connects between the hydrogen source tank 220 and the electric power generating apparatus 1 was provided. A pump (not shown) was provided in the middle of the pipe. Further, a cock (not shown) that allows air to flow into the power generation apparatus 1 was provided.
As control means for controlling the water supply amount and the air supply amount to the power generation device of the power generation device 1, the oxygen discharge amount from the power generation device, the water discharge amount, the amount of sunlight irradiated to the power generation device, the switch, and the like, 16 Built in the body of a car using a bit microcomputer.
Further, in the automobile power generation system 200, water generated by power generation is returned to the hydrogen source tank (220).

Although the present invention has been described in detail with some preferred embodiments, the present invention is not limited to these embodiments, and various modifications are possible within the scope of the gist of the present invention.
For example, it can be incorporated in a paint film or window glass painted on the outer plate of the vehicle.

It is the schematic which shows an example of the electric power generating apparatus of this invention. It is explanatory drawing which shows schematic cross-sectional shape of an example of an electronic storage part. It is explanatory drawing which shows schematic sectional shape of an example of the switch comprised using FET. It is explanatory drawing which shows an example of the electronic state of the component of an electric power generating apparatus, and the flow of an electron and a hole (in the case of a charge separation material: plasmon fine particle, the 1st electrically conductive material: conductive carbon, an electron storage material: a metal material, 1st 2 Electrically conductive material: in the case of conductive carbon). It is explanatory drawing which shows an example of the electronic state of the component of an electric power generating apparatus, and the flow of an electron and a hole (in the case of charge separation material: pigment | dye, 1st electric conduction material: conductive carbon, electron storage material: metal material, 2nd Electrically conductive material: for conductive carbon). It is explanatory drawing which shows an example of the electronic state of the component of an electric power generating apparatus, and the flow of an electron and a hole (Charge separation material: Plasmon fine particle, 1st electric conduction material: FTO, electron storage material: Conductive polymer or metal oxide ( Semiconductor), second electrically conductive material: in the case of conductive carbon). It is explanatory drawing which shows an example of the electronic state of the component of an electric power generating apparatus, and the flow of an electron and a hole (Charge separation material: Dye, 1st electric conduction material: FTO, electron storage material: Conductive polymer or metal oxide (semiconductor ), Second electrically conductive material: in the case of conductive carbon). It is explanatory drawing which shows an example of the electronic state of the component of an electric power generating apparatus, and the flow of an electron and a hole (Charge separation material: Plasmon fine particle, 1st electric conduction material: FTO, electron storage material: Metal material, 2nd electric conduction material : For conductive carbon). It is a graph which shows an example of the absorption spectrum of a visible light responsive photocatalyst material and a charge separation material (when charge separation material is a gold nanoparticle). It is the schematic which shows an example of the structure of a 1st electrode. It is the schematic which shows the other example of the structure of a 1st electrode. It is the schematic which shows the further another example of the structure of a 1st electrode. It is the schematic which shows an example of the structure of a 2nd electrode. It is the schematic which shows the other example of the structure of a 2nd electrode. It is the schematic which shows an example of the structure of the layer containing a plasmon microparticle, and its electronic structure change figure. It is the schematic which shows an example of the structure of the layer containing a pigment | dye, and its electronic structure change figure. A layer containing a plasmon particles is a schematic diagram and its electronic structure change diagram illustrating an example of a laminated structure of a layer containing C _60. It is the schematic which shows an example of the electric power generation system of this invention. It is a flowchart which shows an example of the control flow of the electric power generating apparatus of this invention. It is a schematic block diagram of the electric power generating apparatus of Example 1. It is the schematic which shows an example of the electric power generation system for motor vehicles.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power generator 10 1st electrode 11 Single layer 12 1st layer 13 2nd layer 13a Gold fine particle 14 3rd layer 14a TaON
20 proton conducting part 30 second electrode 31 single layer 32 first layer 33 second layer 40 electron accumulating part 42 electron accumulating material 44 insulating material 50 proton accumulating part 52 proton accumulating material 54 proton outflow preventing material 60 switch 61 substrate 62 channel 63 Source 64 Drain 65 Insulator layer 66 Gate 70 Current detector 80 Photo detector 90 Light transmissive casing 100 Power generation system 110 Supply means 120 Control means 130 Discharge means 200 Automotive power generation system 210 Roof 220 Hydrogen source tank

Claims (23)

A power generator that generates power from a hydrogen source containing oxygen and a compound containing hydrogen as a constituent element using visible light emitted from a light source,
A first electrode, a proton conducting unit, a second electrode, an electron accumulating unit, a proton accumulating unit, and a switch;
The proton conducting part is sandwiched between the first electrode and the second electrode, and is joined to the proton accumulating part,
The first electrode and the second electrode are electrically connected from the first electrode side through the electron storage section and the switch capable of electrically connecting the first electrode and the second electrode in this order. Connected,
The first electrode contains a first electrically conductive material, a visible light responsive photocatalytic material, and a charge separation material,
The power generation apparatus, wherein the second electrode includes a second electrically conductive material and a metal material.   The power generator according to claim 1, further comprising a current detector between the first electrode and the electron storage unit.   The power generation device according to claim 1, further comprising a photodetector. The first electrode has a structure in which a layer containing the first electrically conductive material, a layer containing the charge separation material, and a layer containing the visible light responsive photocatalytic material are sequentially laminated on the proton conducting portion. Have
As the layer containing the visible light responsive photocatalytic material moves to the layer containing the first electrically conductive material, the energy level at the lower end of the conduction band of the band structure of each material in the layer decreases, and each The power generator according to any one of claims 1 to 3, wherein the energy level at the upper end of the valence band of the band structure of the material is increased.   The power generation device according to any one of claims 1 to 4, wherein the charge separation material contains fine particles exhibiting plasmon absorption.   The fine particles exhibiting plasmon absorption are simple metals or alloys containing at least one selected from the group consisting of gold, silver and platinum, and the shape thereof is a nano-sized rod and / or sphere. The power generator according to claim 5.   The power generator according to claim 6, wherein the shape of the fine particles exhibiting plasmon absorption is rod-shaped, the major axis of the rod is 10 to 100 nm, and the minor axis is 5 to 50 nm.   The power generator according to claim 6, wherein the shape of the fine particles exhibiting plasmon absorption is spherical, and the diameter of the sphere is 2 to 50 nm.   The power generation device according to any one of claims 1 to 8, wherein the charge separation material contains a dye exhibiting absorption in a visible light region.   10. The power generation according to claim 9, wherein the dye exhibiting absorption in the visible light region is at least one selected from the group consisting of a porphyrin compound, a metal complex thereof, a phthalocyanine compound, and a metal complex thereof. apparatus.   The layer containing a dye protective material is provided between the layer containing the visible light responsive photocatalyst material and the layer containing the dye exhibiting absorption in the visible light region. Power generator.   The power generation device according to any one of claims 1 to 11, wherein the charge separation material contains fullerenes.   The power generation material according to claim 12, wherein the charge separation material containing the fullerenes is disposed so as to be bonded to the fine particles exhibiting plasmon absorption and / or the dye exhibiting absorption in the visible light region. apparatus.   The first electrical conductive material and / or the second electrical conductive material is selected from the group consisting of conductive carbon particles, conductive carbon porous body, conductive carbon cloth, conductive glass fiber, and conductive glass porous body. The power generation device according to claim 1, wherein the power generation device is at least one type.   The said metal material is platinum, The electric power generating apparatus as described in any one of Claims 1-14 characterized by the above-mentioned. The electron accumulating portion comprises at least one electron accumulating material selected from the group consisting of polymers, metals and metal oxides, and an insulating material;
The power generation device according to claim 1, wherein the electron storage material has a structure covered with the insulating material. The proton accumulating portion comprises at least one proton accumulating material selected from the group consisting of a solid polymer, glass and a metal oxide, and a proton outflow prevention material;
The power generation device according to any one of claims 1 to 16, wherein the proton storage material has a structure covered with the proton outflow prevention material.   The power generation apparatus according to any one of claims 1 to 17, wherein the hydrogen source containing a compound having hydrogen as a constituent element is water or an aqueous solution containing a sacrificial reagent.   The power generation device according to any one of claims 1 to 18, wherein the power generation device is disposed in a light-transmitting casing. A power generation method using the power generation device according to any one of claims 1 to 19,
A hydrogen source containing a compound having hydrogen as a constituent element is brought into contact with a visible light responsive photocatalyst material, the visible light responsive photocatalyst material is irradiated with visible light from a light source, and a compound having the hydrogen as a constituent element is contained. A power generation method characterized by generating protons and electrons from a hydrogen source, controlling the flow of the protons and electrons thus obtained, reacting them with oxygen, and controlling the amount of power generation. A power generation system using the power generation device according to any one of claims 1 to 19,
The power generation device,
Supply means for supplying a hydrogen source containing a compound having hydrogen as a constituent element to the power generation device;
Supply means for supplying oxygen to the power generator;
Discharging means for discharging oxygen from the power generation device;
Discharging means for discharging water from the power generation device;
Control means for controlling the supply amount of a hydrogen source containing a compound having hydrogen as a constituent element to the power generation device;
Control means for controlling the amount of oxygen supplied to the power generator;
Control means for controlling the amount of water discharged from the power generator;
Control means for controlling the amount of oxygen discharged from the power generator;
Control means for controlling the irradiation amount of visible light from the light source to the power generation device;
Control means for controlling the on / off state of the switch of the power generator, and
An on / off state control means for the switch intermittently controls on / off of the switch.   When the on / off state control means of the switch intermittently controls the on / off of the switch, the data from the photodetector of the power generator and the integrated calculation data from the current detector of the power generator, The power generation system according to claim 21, wherein the switch is controlled to be turned on / off based on the control.   23. The power generation system according to claim 21, further comprising a circulation means for reusing water discharged from the power generation apparatus as a hydrogen source containing a compound having hydrogen as a constituent element as a fuel.

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