JP6656590B2 - Photocatalyst device - Google Patents

Description

  Embodiments of the present invention relate to a photocatalytic device.

Reflecting the growing awareness of health, there is an increasing demand for purifying air in so-called semi-closed spaces, such as in vehicles such as automobiles, refrigerators, and living spaces. For example, there has been an increasing demand for removing ammonia and ethylene generated from food, removing volatile organic compounds (VOCs) such as acetaldehyde contained in cigarette smoke, or removing bacteria and inactivating viruses. .
Therefore, a photocatalytic device including a light emitting diode and a photocatalyst sheet carrying a photocatalyst has been proposed.
Here, a photocatalyst sheet extending in a direction perpendicular to the gas flow direction is provided inside the gas flow path, or a plurality of photocatalyst sheets extending in a direction parallel to the gas flow direction are separated from the inner wall surface of the gas flow path. If it is provided at a different position, it becomes easier to trap the gas. If gas can be trapped, gas decomposition performance can be improved.
However, in this case, the gas flow is interrupted, so that the pressure loss increases. If the pressure loss increases, it becomes difficult to increase the gas flow rate and increase the gas flow rate, and it may not be possible to improve the processing capacity.
Therefore, development of a photocatalyst device capable of improving the processing capacity has been desired.

JP 2013-169408 A JP 2011-143133 A

  The problem to be solved by the present invention is to provide a photocatalyst device capable of improving the processing capacity.

Photocatalytic device according to the embodiment is an internal shape is polygonal cross-section, a cylindrical housing having a plurality of inner wall surfaces; provided in the first inner wall surface of the housing, the plurality first A first light source unit having a light-emitting element, and having a plurality of first light-emitting elements having irregularities on a side opposite to the first inner wall surface side ; a first light source unit facing the first inner wall surface of the housing; A first photocatalyst portion provided on the inner wall surface of the second and having a first photocatalyst; a first photocatalyst portion provided on a third inner wall surface adjacent to one side of the second inner wall surface and having a second photocatalyst; 2 of a photocatalyst unit; comprising a distance between the respective light emitting surfaces of the plurality of first light-emitting element, and the first photocatalyst section, is, 1 mm or more, Ru der below 100 mm.

  According to the embodiment of the present invention, it is possible to provide a photocatalyst device capable of improving the processing capacity.

FIG. 1 is a schematic perspective view illustrating a photocatalyst device 1 according to the present embodiment. FIG. 2 is a schematic cross-sectional view of the photocatalyst device 1 in FIG. 1 taken along the line AA. It is the figure which looked at the photocatalyst device 1 in FIG. 1 from the B direction. FIG. 3 is a schematic perspective view illustrating a photocatalyst unit 4. It is a schematic cross section for illustrating arrangement of light source part 3 and photocatalyst part 4 concerning other embodiments. It is a schematic cross section for illustrating the case 12 concerning other embodiments.

Hereinafter, embodiments will be described with reference to the drawings. In each of the drawings, similar components are denoted by the same reference numerals, and detailed description will be omitted as appropriate.
FIG. 1 is a schematic perspective view for illustrating a photocatalyst device 1 according to the present embodiment.
FIG. 2 is a schematic cross-sectional view of the photocatalyst device 1 in FIG.
In FIG. 2, the photocatalyst unit 4 provided on the inner wall surface 2f is omitted to avoid complication.
FIG. 3 is a view of the photocatalyst device 1 in FIG.
FIG. 4 is a schematic perspective view illustrating the photocatalyst unit 4.

  As shown in FIGS. 1, 2, and 3, the photocatalyst device 1 includes a housing 2, a light source unit 3, and a photocatalyst unit 4.

The housing 2 has a tubular shape. The housing 2 has a plurality of inner wall surfaces.
The inner shape of the cross section of the housing 2 is preferably a polygon in consideration of ease of attachment of the light source unit 3 and the photocatalyst unit 4. The inner shape of the cross section of the housing 2 illustrated in FIG. 1 is a quadrangle. Therefore, the housing 2 includes an inner wall surface 2c (corresponding to an example of a first inner wall surface), an inner wall surface 2d (corresponding to an example of a second inner wall surface), and an inner wall surface 2e (corresponding to a fourth inner wall surface). And an inner wall surface 2f (corresponding to an example of a third inner wall surface).
One end 2a of the housing 2 and the other end 2b of the housing 2 are open.
For example, the end 2a of the housing 2 serves as a gas inlet. The end 2b of the housing 2 serves as a gas outlet. The gas is, for example, a gas containing air as a main component.

The material of the housing 2 is not particularly limited.
However, if the material of the housing 2 is a thermoplastic resin, the housing 2 can be formed using an injection molding method.
In this case, if the material of the housing 2 is an acrylic resin (polymethyl methacrylate resin), it is possible to improve the resistance to the ultraviolet rays emitted from the light source unit 3 and the resistance to the VOC contained in the gas. When the degree of polymerization of the acrylic resin is about 10,000 to 15,000, odor can be suppressed.
Further, if the material of the housing 2 is ABS resin (acrylonitrile butadiene-styrene copolymer synthetic resin), it is possible to improve the moldability and reduce the cost. In this case, if the material of the housing 2 is a reinforced ABS resin, the strength of the housing 2 can be improved. The reinforced ABS resin is a mixture of ABS resin and glass fiber.

When the light emitting element 3b generates a large amount of heat, the casing 2 can be formed using a material having high thermal conductivity from the viewpoint of heat dissipation.
Examples of the material having high thermal conductivity include metal, high thermal conductive resin, and ceramics such as aluminum oxide and aluminum nitride.
The high thermal conductive resin is, for example, a resin such as PET (polyethylene terephthalate) or nylon mixed with a filler made of aluminum oxide or the like having high thermal conductivity.

The light source unit 3 irradiates light having a predetermined wavelength toward the photocatalyst unit 4.
The light source unit 3 is provided inside the housing 2. The light source unit 3 has a form extending in the direction in which the housing 2 extends. The light source unit 3 is provided on the inner wall surface 2c of the cylindrical housing 2. The light emitting surface 3b1 of the light emitting element 3b provided in the light source unit 3 faces the photocatalyst sheet 4b provided in the photocatalyst unit 4.

The light source unit 3 has a substrate 3a and a light emitting element 3b.
The substrate 3a has a plate shape. A wiring pattern is provided on one surface of the substrate 3a.
The material and structure of the substrate 3a are not particularly limited. For example, the substrate 3a can be formed from an inorganic material (ceramic) such as aluminum oxide or aluminum nitride, or an organic material such as paper phenol or glass epoxy. Further, the substrate 3a may be a metal plate whose surface is covered with an insulating material. When the surface of the metal plate is coated with an insulating material, the insulating material may be made of an organic material or may be made of an inorganic material.

When the light emitting element 3b generates a large amount of heat, it is preferable to form the substrate 3a using a material having high thermal conductivity from the viewpoint of heat dissipation. Examples of the material having a high thermal conductivity include ceramics such as aluminum oxide and aluminum nitride, a high thermal conductive resin, and a metal plate whose surface is coated with an insulating material.
Further, the substrate 3a may be a single layer or a multilayer.

The light emitting element 3b is provided on one surface of the substrate 3a. The light emitting element 3b is electrically connected to a wiring pattern provided on the surface of the substrate 3a.
The type of the light emitting element 3b is not particularly limited.
The light emitting element 3b can be, for example, a surface mounted light emitting element such as a PLCC (Plastic Leaded Chip Carrier) type.
The light emitting element 3b may be, for example, a light emitting element having a lead wire such as a shell type.

  Further, the light emitting element 3b can be mounted by a COB (Chip On Board). When the light-emitting element 3b is mounted by COB, the chip-shaped light-emitting element 3b, wiring for electrically connecting the light-emitting element 3b to the wiring pattern, and sealing for covering the chip-shaped light-emitting element 3b and the wiring are provided. And the like can be provided on the substrate 3a.

  The light emitting element 3b can be, for example, a light emitting diode. A plurality of light emitting elements 3b can be provided. The plurality of light emitting elements 3b can be connected in series. The arrangement of the plurality of light emitting elements 3b is not particularly limited. The plurality of light emitting elements 3b can be provided side by side along the direction in which the housing 2 extends. The plurality of light emitting elements 3b illustrated in FIG. 1 are arranged in a line along the direction in which the housing 2 extends. However, the plurality of light emitting elements 3b can be provided, for example, in a matrix. When a plurality of light emitting elements 3b are arranged side by side, the plurality of light emitting elements 3b can be arranged at equal pitch intervals, or the plurality of light emitting elements 3b can be arranged at different pitch dimensions.

Here, the speed of the photocatalytic reaction varies depending on the absorption wavelength region of the photocatalyst and the light intensity (light amount). Therefore, the disposition mode and the number of the plurality of light emitting elements 3b are determined by the amount of light emitted by one light emitting element 3b, the area of the photocatalyst sheet 4b carrying the photocatalyst, and the light emitting surface 3b1 of the light emitting element 3b. It can be determined based on the distance L to the photocatalyst sheet 4b.
For example, the arrangement form and number of the plurality of light emitting elements 3b can be set so that the light irradiation intensity on the photocatalyst sheet 4b is 1 mW / cm ² or more.

Further, if the material or composition of the photocatalyst changes, the absorption wavelength region of the photocatalyst changes. Therefore, the light emitting element 3b that emits light of an appropriate wavelength is appropriately selected according to the absorption wavelength region of the photocatalyst.
For example, when the photocatalyst is an ultraviolet light responsive photocatalyst such as titanium oxide, the light emitting element 3b can emit light having a peak wavelength of 380 nm or less.
When the photocatalyst is a visible light responsive photocatalyst such as tungsten oxide, the light emitting element 3b can emit light having a peak wavelength of 380 nm or more (for example, about 400 nm to 600 nm).

The photocatalyst unit 4 has a photocatalyst. The photocatalyst unit 4 decomposes and removes harmful substances contained in the gas, removes bacteria, inactivates viruses, and the like by photocatalysis.
The photocatalyst unit 4 is provided inside the housing 2. The photocatalyst unit 4 has a form extending in the direction in which the housing 2 extends. The photocatalyst unit 4 is provided on the inner wall surface 2 d of the housing 2 and faces the light source unit 3. That is, the photocatalyst unit 4 having the photocatalyst is provided on the inner wall surface 2d of the housing 2 facing the inner wall surface 2c on which the light source unit 3 is provided.
The photocatalyst sheet 4b faces the light emitting surface 3b1 of the light emitting element 3b.
Note that the photocatalyst unit 4 is parallel to the light source unit 3 because the inner shape of the cross section of the housing 2 is square, but depending on the inner shape of the cross section of the housing 2, the photocatalyst unit 4 is 3 may be inclined. However, if the photocatalyst unit 4 is parallel to the light source unit 3, more uniform light irradiation is performed, so that the processing capacity can be improved.
The space between the light source unit 3 and the photocatalyst unit 4 is a flow path through which gas flows.

A plurality of photocatalyst units 4 can be provided. Although the case where three photocatalyst units 4 are provided is illustrated, the number of photocatalyst units 4 can be changed as appropriate.
For example, the photocatalyst device 1 is provided on an inner wall surface 2d facing the inner wall surface 2c of the housing 2, and has a first photocatalyst portion having a first photocatalyst and an inner wall surface 2f adjacent to one side of the inner wall surface 2d. And a second photocatalyst unit having a second photocatalyst.
Further, the photocatalyst device 1 can further include a third photocatalyst provided on the inner wall surface 2e facing the inner wall surface 2f and having the first or second photocatalyst.
The composition of the first photocatalyst and the composition of the second photocatalyst may be different. The composition of the first photocatalyst and the composition of the second photocatalyst may be the same.
In this case, if the number of the photocatalyst units 4 is increased, the processing capacity can be improved. That is, it is preferable to provide the photocatalyst unit 4 on an inner wall surface other than the inner wall surface on which the light source unit 3 is provided.

As shown in FIG. 1, the light source unit 3 and one photocatalyst unit 4 face each other. The light source unit 3 and the other two photocatalyst units 4 are provided adjacent to each other. For example, the light source unit 3 can be provided on the inner wall surface 2c. A photocatalyst unit 4 can be provided on the inner wall surface 2d, the inner wall surface 2e, and the inner wall surface 2f.
If the photocatalyst unit 4 is provided on the inner wall surface 2d, the inner wall surface 2e, and the inner wall surface 2f, the area of the photocatalyst sheet 4b can be increased. Further, as described later, the gas contained in the gas flow G2 and the gas flow G3 easily comes into contact with the photocatalyst sheet 4b provided on the inner wall surfaces 2e and 2f. Therefore, the processing capacity can be improved.

In this case, the configuration of the photocatalyst unit 4 may be the same or different. The photocatalyst units 4 having different configurations can be, for example, a photocatalyst unit 4 including an ultraviolet light responsive photocatalyst and a photocatalyst unit 4 including a visible light responsive photocatalyst. In this case, a part of the plurality of light emitting elements 3b provided in the light source unit 3 is irradiated with light having a peak wavelength of 380 nm or less, and the remaining light emitting elements 3b have a peak wavelength of 380 nm or more (for example, about 400 nm to 600 nm). ) May be applied.
If the photocatalyst units 4 having different configurations are provided, gas types having excellent adsorption performance in the respective photocatalyst units 4 can be made different. Therefore, for example, when processing a gas in which a plurality of types of gas are mixed, the gas can be efficiently decomposed and removed.

As shown in FIG. 4, the photocatalyst part 4 has a frame part 4a and a photocatalyst sheet 4b.
The frame portion 4a has a frame shape and holds the periphery of the photocatalyst sheet 4b. The central portion of the frame 4a is a window 4a1 from which the photocatalyst sheet 4b is exposed.
When the area of the photocatalyst sheet 4b is large, the beam 4a2 can be provided to suppress the bending in the central region of the photocatalyst sheet 4b.

The frame part 4a is provided as a pair. The photocatalyst sheet 4b is held by sandwiching the photocatalyst sheet 4b between the pair of frame portions 4a.
In this case, a protrusion can be provided on the peripheral edge of one frame 4a, and a recess can be provided on the peripheral edge of the other frame 4a so as to be fitted to the projection. Then, when the photocatalyst sheet 4b is sandwiched between the pair of frame portions 4a, the projections are fitted into the concave portions so that the pair of frame portions 4a can be fixed to each other. The pair of frame portions 4a may be fixed to each other by using an ultrasonic welding method or the like.

The photocatalyst sheet 4b has, for example, a glass fiber fabric and a photocatalyst.
The glass fiber woven fabric can be, for example, a woven fabric composed of a group of weft yarns and a group of warp yarns obtained by bundling transparent glass fibers.
A large number of photocatalyst fine particles are supported between glass fibers.
In this case, the photocatalyst sheet 4b can be created, for example, as follows.
First, phosphoric acid is added to pure water to produce an aqueous solution whose pH (hydrogen ion concentration) is adjusted to 2 to 7, and a photocatalyst is added to produce an emulsion solution.
Next, the glass fiber fabric is immersed in the emulsion solution for about 10 minutes.
Next, the glass fiber fabric is pulled up from the emulsion solution and dried.
Thus, the photocatalyst sheet 4b in which a large number of photocatalyst fine particles are carried between glass fibers can be produced.

Further, the photocatalyst sheet 4b may have, for example, a ceramic substrate and a photocatalyst. The ceramic substrate can be, for example, a porous alumina substrate. A large number of photocatalyst fine particles are carried inside the holes of the ceramic substrate or on the substrate surface.
In this case, the photocatalyst sheet 4b can be created, for example, as follows.
First, an emulsion solution is generated in the same manner as described above.
Next, the ceramic substrate is immersed in the emulsion solution.
Next, the ceramic substrate is pulled up from the emulsion solution, and the ceramic substrate is heated by a heating furnace or the like. The heating temperature can be about 100 ° C., and the heating time can be about 2 hours.
In this manner, the photocatalyst sheet 4b in which a large number of photocatalyst fine particles are carried inside or on the surface of the hole can be produced.

  The photocatalyst may have, for example, a granular shape. The photocatalyst can be appropriately selected according to the use of the photocatalyst device 1 and the like. For example, the photocatalyst can be an ultraviolet light responsive photocatalyst, a visible light responsive photocatalyst, or the like. The ultraviolet light responsive photocatalyst can be, for example, titanium oxide. The visible light responsive photocatalyst can be, for example, tungsten oxide, titanium oxide doped with nitrogen or the like, titanium oxide ion-implanted with a different metal, or the like.

  Further, the photocatalyst device 1 may be provided with a power supply 10 for supplying power to the light emitting element 3b via a wiring pattern. In addition, the photocatalyst device 1 can be appropriately provided with a wiring, a connector, and the like for electrically connecting the power supply 10 to the wiring pattern provided on the substrate 3a.

Here, a photocatalyst portion 4 (photocatalyst sheet 4b) extending in a direction perpendicular to the gas flow direction is provided inside the housing 2, or a plurality of photocatalysts are provided inside the housing 2 at a position away from the inner wall surface. A part 4 (photocatalyst sheet 4b) can also be provided. This makes it easier to trap the gas, so that the gas decomposition performance can be improved.
However, in this case, the gas flow is interrupted, so that the pressure loss increases. If the pressure loss increases, it becomes difficult to increase the gas flow rate and increase the gas flow rate, and it may not be possible to improve the processing capacity.

  In the photocatalyst device 1 according to the present embodiment, the light source unit 3 is provided on the inner wall surface 2c of the housing 2. In addition, the photocatalyst unit 4 is provided on the inner wall surfaces 2d to 2f of the housing 2. Therefore, it is possible to suppress the gas flow from being interrupted. As a result, it is possible to increase the flow rate of the gas and increase the flow rate of the gas, thereby improving the processing capacity.

Here, if the flow of gas is smooth, there is a possibility that the amount of gas that simply passes through the inside of the housing 2 without approaching the photocatalyst sheet 4b carrying the photocatalyst may increase. If the amount of gas that simply passes through the inside of the housing 2 increases, the processing capacity may be reduced.
As shown in FIG. 2, the gas flow G <b> 1 and the gas flow G <b> 2 formed between the light source unit 3 and the photocatalyst unit 4 have little obstruction to the gas flow, so that the gas flow disturbance is reduced.
In this case, the gas flow G1 flows near the photocatalyst unit 4 even if the flow of the gas is small, so that the gas easily comes into contact with the photocatalyst sheet 4b. Therefore, by the photocatalytic action of the photocatalyst sheet 4b, harmful substances contained in the gas can be decomposed and removed.

  On the other hand, the gas flow G3 is disturbed by the unevenness formed by the plurality of light emitting elements 3b. If the flow of the gas flow G3 is disturbed, the flow of the adjacent gas flow G2 can be disturbed. If the flows of the gas flow G2 and the gas flow G3 are disturbed, the gas contained in the gas flow G2 and the gas flow G3 easily comes into contact with the photocatalyst sheet 4b provided on the inner wall surfaces 2e and 2f. Therefore, the processing capacity can be improved.

  In this case, if the distance L between the light emitting surface 3b1 of the light emitting element 3b and the surface of the photocatalyst sheet 4b is too long, the gas contained in the gas flow G2 and the gas flow G3 and the photocatalyst sheet provided on the inner wall surface 2d 4b becomes difficult to contact. On the other hand, if the distance L between the light emitting surface 3b1 of the light emitting element 3b and the surface of the photocatalyst sheet 4b is too short, the pressure loss may be too large. That is, even if the distance L is too long or too short, the processing capability may be reduced.

  According to the knowledge obtained by the present inventor, if the gas flow velocity is 0.04 m / s or more and 0.50 m / s or less, the distance L is preferably 1 mm or more and 100 mm or less. By doing so, the processing capacity can be improved.

FIG. 5 is a schematic cross-sectional view illustrating the arrangement of the light source unit 3 and the photocatalyst unit 4 according to another embodiment.
As shown in FIG. 5, two sets of the light source unit 3 and the photocatalyst unit 4 can be provided. Although the inside shape of the cross section of the housing 2 is a quadrangle, two sets of the light source unit 3 and the photocatalyst unit 4 are illustrated. It can be changed appropriately according to the shape.

As shown in FIG. 5, one light source unit 3 and photocatalyst unit 4 face each other. The other light source unit 3 and the photocatalyst unit 4 face each other. For example, the light source unit 3 can be provided on each of the inner wall surface 2c and the inner wall surface 2e. A photocatalyst unit 4 can be provided on each of the inner wall surface 2d and the inner wall surface 2f.
That is, the photocatalyst device 1 is provided on the inner wall surface 2c of the housing, and provided on the first light source unit having the first light emitting element and the inner wall surface 2e facing the inner wall surface 2f. And a second light source unit.
If a plurality of sets of the light source unit 3 and the photocatalyst unit 4 are provided, the processing capability can be improved.

In this case, the configurations of the two light source units 3 and the photocatalyst unit 4 may be the same or different.
When the two light source units 3 and the photocatalyst unit 4 have different configurations, for example, the peak wavelength of the light emitted by the first light emitting element and the peak wavelength of the light emitted by the second light emitting element are different. It can be different. For example, one light source unit 3 emits light having a peak wavelength of 380 nm or less, and the photocatalyst unit 4 facing the light source unit 3 includes an ultraviolet light responsive photocatalyst. The other light source unit 3 emits light having a peak wavelength of 380 nm or more (for example, about 400 nm to 600 nm), and the photocatalyst unit 4 facing the light source unit 3 includes a visible light responsive photocatalyst. To do.
If the photocatalyst units 4 having different configurations are provided, gas types having excellent adsorption performance in the respective photocatalyst units 4 can be made different. Therefore, for example, when processing a gas in which a plurality of types of gas are mixed, the gas can be efficiently decomposed and removed.

FIG. 6 is a schematic cross-sectional view illustrating a housing 12 according to another embodiment.
As shown in FIG. 6, the inner shape of the cross section of the housing 12 can be a rectangle.
In this case, it is preferable that the light source unit 3 be provided on the inner wall surface 12c on the long side of the rectangle and the photocatalyst unit 4 be provided on the inner wall surface 12d on the long side of the rectangle.
By doing so, the distance L between the light emitting surface 3b1 of the light emitting element 3b and the surface of the photocatalyst sheet 4b can be reduced. If the distance L can be shortened, the intensity of light applied to the photocatalyst sheet 4b can be increased. Further, the gas contained in the gas flow G2 and the gas flow G3 described above easily comes into contact with the photocatalyst sheet 4b.
Further, if the photocatalyst portion 4 is provided on the inner wall surface 12d on the long side of the rectangle, the area of the photocatalyst sheet 4b can be increased.
Therefore, the processing capacity can be improved.

If the photocatalyst portion 4 is provided also on the inner wall surfaces 12e and 12f on the shorter side of the rectangle, the area of the photocatalyst sheet 4b can be further increased.
Therefore, the processing capacity can be further improved.

  While some embodiments of the present invention have been described above, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. These new embodiments can be implemented in other various forms, and various omissions, replacements, changes, and the like can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents. The above-described embodiments can be implemented in combination with each other.

  Reference Signs List 1 photocatalyst device, 2 housing, 2c inner wall surface, 2d inner wall surface, 2e inner wall surface, 2f inner wall surface, 3 light source section, 3a substrate, 3b light emitting element, 4 photocatalyst section, 4a frame section, 4b photocatalyst sheet, 10 power supply, 12 housing, 12c inner wall surface, 12d inner wall surface, 12e inner wall surface, 12f inner wall surface

Claims (6)

A cylindrical housing having a polygonal cross-sectional inner shape and a plurality of inner wall surfaces;
Wherein provided on the first inner wall surface of the housing includes a plurality of first light-emitting element, wherein the first inner wall surface first with irregularities by the plurality of first light emitting element on the opposite side A light source section;
A first photocatalyst unit provided on a second inner wall surface facing the first inner wall surface of the housing and having a first photocatalyst;
A second photocatalyst unit provided on a third inner wall surface adjacent to one side of the second inner wall surface and having a second photocatalyst;
Equipped with,
The photocatalyst device, wherein a distance between each of the light emitting surfaces of the plurality of first light emitting elements and the first photocatalyst unit is 1 mm or more and 100 mm or less .
  The photocatalyst device according to claim 1, wherein a composition of the first photocatalyst is different from a composition of the second photocatalyst.   The photocatalyst device according to claim 1, wherein the composition of the first photocatalyst is the same as the composition of the second photocatalyst.   The photocatalyst device according to any one of claims 1 to 3, further comprising a second light source unit provided on a fourth inner wall surface facing the third inner wall surface and having a second light emitting element.   4. The device according to claim 1, further comprising a third photocatalyst provided on a fourth inner wall surface facing the third inner wall surface and having the first photocatalyst or the second photocatalyst. 5. The photocatalyst device according to item 1.   The photocatalyst device according to claim 4, wherein a peak wavelength of light emitted by the first light emitting element is different from a peak wavelength of light emitted by the second light emitting element.

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