JP2002035597A - Photocatalyst member and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocatalyst member having a photocatalytic layer, composed mainly of a TiOx layer (x is a numerical value represented by 1.99<x<2)., which is excitable not only in an ultraviolet light region but also in a specified visible light region and can be formed to a specified thickness which is easily controllable, on the surface of a base and besides, is mass- producible in a temperature region where a common metal or the like does not melt and can be manufactured at a low cost as well as a manufacturing method for the photocatalyst member. SOLUTION: The photocatalytic layer is formed by applying a thin TiO2 film in a dry coating fashion on the surface of the base and heating the film in an atmosphere of about 450-1,000 deg.C for a specified time and then quenching.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocatalyst layer, and more particularly to a photocatalyst member which is photoactive in a specific wavelength region from an ultraviolet region to a visible light region and has various functions such as antibacterial, purification and deodorization, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, anatase-type titanium dioxide (TiO2) has high photoactivity as a photocatalyst, and holes (h +) are generated in a valence band and electrons (e-) are generated in a conduction band by photoexcitation. Hydroxyl radicals are generated by an oxidation reaction with water contained in the atmosphere, and electrons are reduced by a reduction reaction with oxygen in the atmosphere to generate superoxide ions. It is known that the strong oxidizing power of the hydroxyl radical and superoxide ion exerts an antibacterial function, a decomposition function, a purification function and the like.

[0003] However, anatase-type titanium dioxide is one that is photo-excited by ultraviolet light in a wavelength range of 380 nm or less, and can exhibit an antibacterial function or a purifying function in sunlight or an ultraviolet lamp, but can exhibit an ultraviolet light range in indoor lighting. For example, in the case of a fluorescent lamp, the photon amount is about 0.5% of the total photon amount.
5%, which is extremely small, the number of holes and electrons excited by ultraviolet rays is small, so the generation of hydroxyl radicals and superoxide ions is overwhelmingly small compared to the number of molecules such as odor components, and the odor components are sufficient. Could not be decomposed.

Therefore, various photocatalysts containing titanium as a main component which are photoexcited by visible light in a wavelength region of 380 nm or more have been studied, and as shown in JP-A-10-146530, the surface layer side is deeper than TiO2, TiOx (X is a numerical value represented by 1.99 <X <2) in which the layer side has a tilted structure of TiO or oxygen defects are generated in TiO2 is expected to be promising.

In the former method, a solution containing a complex of a titanium alkoxide and a chelating agent is applied to the surface of a substrate by a dipping method or another method, and the resultant is heated and fired at 400 to 700 ° C. in an oxidizing atmosphere. By doing this, the coating film undergoes hydrolysis, polycondensation reaction, and oxidation reaction from its outer surface, but due to the presence of the chelating agent, the oxidation reaction is delayed in the depth direction of the coating film thickness, resulting in the formation of a film. The outer surface has a tilted structure in which TiO2 is completely oxidized to become TiO2, and the inside or the interface with the base material becomes TiO with insufficient oxygen.

In the latter case, a method of reducing TiO2 by heating TiO2 in a hydrogen atmosphere has been considered.

[0007]

However, in the former case, a solution containing a complex of a titanium alkoxide and a chelating agent is applied to the surface of the substrate by a dipping method or other methods and heated to form a photocatalyst having a gradient structure. Since the layer is formed, impurities such as titanium alkoxide remain in the photocatalyst layer to reduce the performance of various functions of the photocatalyst, or because of the inclined structure, the specific TiOx layer which is photoactive in a predetermined wavelength region has a very small thickness. However, even when the light amount in the predetermined wavelength region was sufficiently given, the oxidation-reduction reaction could not be sufficiently exhibited.

In the latter case, when TiO2 is to be reduced and produced in a hydrogen atmosphere, very delicate control is required, and it is necessary to heat the TiO2 to 1,700 ° C. to 1,800 ° C. Even if it can be formed, mass production is extremely difficult and impractical.

In view of the above, TiOx (X is a numerical value represented by 1.99 <X <2) by a manufacturing method of laminating a Ti thin film layer and a TiO2 thin film layer previously applied by the present applicant and heating them. Is also conceivable.

However, according to this manufacturing method, for example, when the value of Z is 1.995, the thickness of the Ti thin film must be extremely thinner than the thickness of the TiO2 thin film as can be seen from the following equation. . TiO2 + aTi = (1 + a) Ti + O2 = (1 + a)
(Ti + O2 / 1 + a) X = 2 / (1 + a) = 1.995a = (2 / 1.995) -1 = 0.0025 Therefore, for example, when the thickness of the TiO2 thin film layer is 400 nm, the thickness of the Ti thin film layer is Needs to be controlled to a very thin film thickness of about 1 nm, and the manufacturing equipment becomes expensive.

Further, when dry coating Ti,
Ti is oxidized by a very small amount of oxygen remaining in the dry coating chamber, and together with the difficulty of controlling a very thin film thickness, as a result, the value of X of TiOx greatly fluctuates from the target value. However, mass production has many problems to be solved.

The present invention solves these problems and provides a TiOx layer (X is a numerical value represented by 1.99 <X <2) on a substrate surface.
The main component is a photocatalyst layer that excites in the visible light region as well as in the ultraviolet region, as well as in the ultraviolet region.The thickness of the layer can be easily controlled. An object of the present invention is to provide a photocatalyst member that can be produced and can be manufactured at low cost, and a method for manufacturing the same.

[0013]

In order to solve the above-mentioned problems, a photocatalyst member and a method for manufacturing the same according to the present invention are disclosed in which a TiO2 thin film is dry-coated on the surface of a substrate to form a photocatalyst member having a thickness of about 450 to 5,000.
The photocatalyst layer is formed by heating in a 1,000 ° C. atmosphere for a predetermined time and then rapidly cooling.

As described above, a simple method such as heat-treating after dry-coating a TiO2 thin film on the surface of a base material,
Ti having anatase type when quenched by heating at about 450 ° C. for about 10 to 20 hours, or rutile type when quenched by heating at about 1,000 ° C. for about 1 to 3 hours
A yellowish photocatalytic layer composed of Ox (X is a numerical value represented by 1.99 <X <2) can be formed, the thickness of the photocatalyst layer can be easily controlled, and at the temperature range where ordinary metals and the like do not melt. It can be mass-produced, can be manufactured at low cost, and has good adhesion of the photocatalyst layer to the substrate.

It is preferable that the substrate is formed of a conductive member, and a reduction catalyst layer for promoting a reduction reaction of electrons generated by the photoexcitation of the photocatalyst layer is formed on the back surface thereof. TiOx (X is 1.99)
TiOx (X is 1.99 <X) having a rutile-type crystal structure, which is considered to be inferior to the anatase-type crystal structure in the reduction reaction, as well as the photocatalyst layer composed of <X <2.
Even in the photocatalyst layer having a value of <2), some of the electrons generated on the photocatalyst layer side move to the reduction catalyst layer side to reduce recombination of electrons and holes, and the photoexcitation causes Most of the generated holes efficiently react with water to generate hydroxyl radicals, and the electrons transferred to the reduction catalyst layer reduce oxygen to generate superoxide ions, which are further reduced by the reduction catalyst layer. The energy potential required for the reduction becomes low, and as a result, even if electrons are excited at the energy level held by the light particles up to about 550 nm in the visible light region, which is abundant in indoor lighting, reduction of oxygen on the reduction catalyst layer side The reaction becomes possible and superoxide ions are generated. On the photocatalyst layer side, hydroxyl radicals and superoxide ions are generated by the oxidation and reduction reactions of holes and some electrons, resulting in both front and back surfaces. It made a strong decomposition function and antibacterial function and purification function, and the like can be efficiently exhibited I 俟.

If a photocatalyst member using a metal mesh as a base material is used, air containing odorous substances, harmful substances such as dioxin, formaldehyde, toluene and the like can be efficiently passed through the mesh. It can be oxidized and decomposed.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing the steps of a method for manufacturing a photocatalyst member of the present invention, and FIG. 2 is a sectional view based on the manufacturing steps.
(A) is a cross-sectional view in which a catalyst thin film is coated on the back surface of a conductive plate-like base material such as a stainless steel plate, and (b) is a TiO.
2 is a cross-sectional view in which a thin film is coated on the substrate surface, (c) is a cross-sectional view after heating and quenching the substrate to form a photocatalytic layer, FIG. 3 is a graph showing an oxidation potential, and FIG. FIG. 5 is a schematic view of an apparatus for coating a material, FIG. 5 is a schematic view of another apparatus for coating a catalyst and TiO 2 on a substrate,
6 is a schematic diagram showing an example in which a photocatalyst member is applied to a filter member and used in an air purifier, FIG. 7 is a schematic diagram showing an example in which the photocatalyst member is applied to a filter member and used in a passenger car, and FIG. 8 is a photocatalyst. FIG. 9 is a schematic diagram showing an example in which the member is applied to a filter member and used in refrigeration / refrigeration equipment. FIG. 9 is a schematic diagram showing an example in which a photocatalyst member is applied to a plate material and used in a trash can. It is a schematic diagram which shows the example applied and used for the water washing machine.

First, the basic manufacturing steps of the method for manufacturing a photocatalyst member according to the present invention will be described with reference to FIGS. 1 and 2. In FIG. B is a step of coating the reduction catalyst layer 2 for promoting the transfer of electrons to oxygen atoms, and B is a step of coating the TiO2 thin film 3 on the other surface of the conductive plate-like substrate 1.
Is a step of performing heat treatment at about 450 to 1,000 ° C. in a non-oxygen atmosphere or an oxygen atmosphere of a predetermined concentration for a predetermined time, and D is thereafter rapidly cooled to have TiOx (X is a number of 1.99 <X <2) as a main component. This is a step of forming the photocatalyst layer 4.

The base material 1 is formed by knitting a stainless steel wire having a wire diameter of 0.1 mm to 0.5 mm, and is formed of 10 mesh to 100 mm.
A mesh material or a plate material having a thickness of 0.1 to 1 mm is used, and a reduction catalyst layer 2 made of platinum is formed on one surface by a dry coating method.

On the other side of the substrate 1, a TiO2 thin film 3 is formed by a dry coating method, and then, in this example, the substrate 1 is heated for about one hour in a non-oxygen atmosphere at about 700.degree. Then, the TiO2 thin film 3 is crystallized in a rutile form, and then left in the air at room temperature to be rapidly cooled.
TiOx with oxygen vacancies (where X is 2 close to 2)
(A smaller number) of the photocatalyst layer 4 having a rutile crystal structure with a yellow tint.

When the reduction catalyst layer 2 is formed of platinum on the surface of the reduction catalyst layer 2 as shown in FIG.
The reduction potential of-) and oxygen (O2) is 0.491 eV in terms of a hydrogen reference potential, whereas in the case of a fabric without the reduction catalyst layer 2, the reduction potential of electrons and oxygen on the surface is- 0.284 eV.

On the other hand, the band gap of rutile TiO2 is 3 eV, and if the reduction catalyst layer 2 containing platinum as a main component is present, as shown in FIG. When the layer 4 is irradiated with visible light, the layer 4 absorbs light having a wavelength up to about 550 nm in the visible light region, and a part of the electrons (e−) photoexcited by the light in these wavelength regions is reduced. The electron (e−) and oxygen (O2) are reduced on the surface of the reduction catalyst layer 2 to generate superoxide ions on the surface of the reduction catalyst layer 2, and a part of the electrons (e−) and holes (h +) Moves to the surface side of the photocatalyst layer 4, and a part of the electrons (e−) reacts with oxygen to generate superoxide ions, and the holes (h +) react with water to generate hydroxyl radicals on the surface of the photocatalyst layer 4. I do.

As described above, it is possible to use electrons having energy excited by light rays (light particles) in a visible light region abundantly present in room lighting, particularly up to a region of around 550 nm. The oxidizing power due to the hydroxyl radical and the superoxide ion act on the side, and the oxidizing power due to the superoxide ion acts on the reduction catalyst layer 2 side, so that a strong decomposing function, an antibacterial function, a purifying function, etc. are effective on both sides of the base material 1. It will be possible to demonstrate in an effective manner.

The photocatalyst layer 4 has a yellow tint because it absorbs and excites light rays (light particles) up to a region around 550 nm and reflects light rays not absorbed but reflected.

A reduction catalyst layer 2 and a TiO2 thin film 3 on a substrate 1
Can be formed by the dry coating method shown in FIGS.

In FIG. 4, the reduction catalyst layer 2
The TiO2 thin film 3 and the TiO2 thin film 3 employ a sputtering method as a dry coating method. The base material 1 made of a belt-shaped stainless steel net material wound into a roll is supplied to the first sputtering chamber 5 and one of the base materials 1 is formed. Sputtering catalyst as a catalytic substance on the surface side of the catalyst layer 2
Is supplied to the second sputtering chamber 6 to continuously form the TiO2 thin film 3 on the other surface side of the substrate 1.

In the first sputtering chamber 5, the belt-shaped substrate 1 wound around the supply drum 7 is continuously supplied to the intermediate drum 8 in a substantially vacuum state in which an inert gas such as argon gas is sealed. Then, platinum as a catalyst substance is sputtered to form a reduction catalyst layer 2 composed of a platinum thin film of about 1 to 5 nm on one surface of the substrate 1, and then supplied to the second sputtering chamber 6.

In the second sputtering chamber 6, for example, a titanium oxide such as TiO 2 is sputtered while being continuously supplied from the intermediate drum 9 to the winding drum 10 under a substantially vacuum state in which a small amount of oxygen gas is sealed. Then, a TiO2 thin film 3 of about 500 nm is formed on the other surface of the substrate 1.

Thereafter, the roll-shaped substrate 1 is placed in a heat treatment tank (not shown) and heated in a non-oxygen atmosphere at about 700 ° C. for 1 hour to make the TiO 2 thin film 3 into a rutile type crystal structure. 1 was taken out of the heat treatment tank, left to stand, rapidly cooled to room temperature level, and the TiO2 thin film 3 was mainly composed of TiOx (X is 1.99 <X <2) having a rutile-type crystal structure and having oxygen defects. The formed photocatalyst layer 4 is formed.

In this example, the thickness of the reduction catalyst layer 2 and the thickness of the TiO 2 thin film were changed by changing the conditions for applying the electric field for evaporating platinum and the conditions for applying the electric field for evaporating titanium oxide while keeping the supply speed of the substrate 1 constant. 3 thickness setting is changed.

As described above, by combining the two sputtering chambers 5 and 6, the reduction catalyst layer 2 and the TiO2 thin film 3 can be continuously formed on the respective surfaces of the strip-shaped substrate 1 separately, so that mass production can be performed efficiently. It becomes possible.

A reduction catalyst layer 2 and a TiO2 thin film 3 on a substrate 1
Can be formed in the ion plating chamber 11 of the ion plating method as shown in FIG.

In this example, the conditions for applying an electric field to the electron gun 12 for evaporating a catalytic substance such as platinum or TiO 2 are kept constant, and the speed at which the roll-shaped substrate 1 is supplied to the ion plating chamber 11 is reduced. By changing
The thickness settings of the reduction catalyst layer 2 and the TiO2 thin film 3 are made variable.

That is, first, as shown in FIG. 5A, the base material 1 wound in a roll is set on the rollers 14 and 15 in the setting chamber 13, and the base material 1 is moved from the roller 14 to the roller 15 in the direction. The electron gun 12 is operated while rotating the rollers 14 and 15 toward the surface of the drum 16 in the ion plating chamber 11 while the substrate 1 is positioned on the surface of the drum 16, and irradiates the platinum target contained in the crucible 17 with an electron beam. Then, the platinum is evaporated, and the substrate 1 is wound around the roller 15 while forming the reduction catalyst layer 2 on one surface of the substrate 1.

Next, as shown in FIG. 5B, the roller 14 and the roller 15 are exchanged and mounted so that a film can be formed on the other surface of the substrate 1, and then the electron beam is applied to the crucible 17 containing TiO2. The substrate 1 is wound around a roller 14 while irradiating the TiO2 to evaporate and forming a TiO2 thin film 3 on the other surface of the substrate 1.

When forming a film of platinum, the inside of the chamber 11 is adjusted to a substantially vacuum state of a non-oxygen atmosphere by adjusting the conditions of an inert gas such as an argon gas. Under a substantially vacuum condition, a small amount of oxygen gas is supplied from the oxygen supply source 18 to the vicinity of the surface of the substrate 1 while evaporating TiO2.

As described above, oxygen is supplied when coating TiO2 because titanium and oxygen atoms are once released during the evaporation of TiO2 if there is no oxygen supply, and a part of the oxygen atoms is substantially in a vacuum state. Is discharged by the operation of a vacuum pump (not shown) in order to maintain the temperature.
A 1.9 component thin film layer is formed. Oxygen atoms are replenished by supplying oxygen, and TiO
A two-component thin film layer 3 is formed.

Thereafter, the roll-shaped substrate 1 is taken out of the setting chamber 13 and heated to about 450 ° C. for about 15 hours in an oxygen atmosphere in the atmosphere by another heat treatment apparatus (not shown) to thereby form a TiO 2 thin film. The layer 3 is made into an anatase type crystal structure, and then the roll-shaped substrate 1 is taken out of the heat treatment apparatus and left to be rapidly cooled to a room temperature level, and TiOx having an anatase type crystal structure (X is 1.99 <X <2) is obtained. The photocatalyst layer 4 as a main component is formed.

The thickness of the reduction catalyst layer 2 may be about 1 to 0.2% as compared with the thickness of the TiO 2 thin film layer 3.
Is the same, the supply speed of the substrate 1 when forming the reduction catalyst layer 2 is 100 to 5 times the supply speed of the substrate 1 when forming the TiO2 thin film layer 3.
What is necessary is just to make it 00 times.

Of course, by adjusting the output of the electron gun 12 and changing the evaporation speed of the target, the reduction catalyst layer 2
The thickness of the TiO2 thin film layer 3 can be controlled, and the reduction catalyst layer 2 and the TiO2 thin film layer 3 can be controlled by combining the supply speed of the substrate 1 to the chamber 11 and the output of the electron gun 12.
The thickness of the two thin film layers 3 may be controlled.

It is preferable that a heater for heat treatment is provided in the setting chamber 13 so as to serve also as a heat treatment device because the production efficiency is increased.

As described above, by forming the photocatalyst layer 4 containing titanium dioxide having oxygen defects as a main component, two electrons are left in the crystal every time one oxygen atom is eliminated.
The remaining two electrons reduce Ti4 + in the crystal to Ti3 +, and the Ti3 + is strongly polarized to form a visible light absorption mechanism.

Next, an example of application to a product is shown in FIG. 6. FIG. 6 shows a case where a 50-mesh net formed by knitting a stainless steel wire having a wire diameter of 0.2 mm as a substrate 1 was used. A photocatalyst layer 4 and a photocatalyst member on which a reduction catalyst layer 2 such as platinum is formed on the back side are used as a filter 19 as an air purifier 2.
In this example, a fan 24 is provided in a casing 23, and a normal lighting fixture 25 such as a fluorescent lamp is mounted on a ceiling or the like.

When the fan 24 is operated while the lighting fixture 25 is turned on or while the sunlight is being inserted, the visible light contained in the sunlight or the visible light generated with the lighting of the lighting fixture 25 is generated. Of the holes and electrons excited from the photocatalyst layer 4 on the surface side of the filter 19 by light up to a wavelength region near 550 nm, on the photocatalyst layer 4 side, the holes and the water contained in the atmosphere undergo an oxidation reaction to form hydroxyl radicals. In addition, a part of the electrons and the oxygen in the air undergo a reduction reaction to generate superoxide ions, and a part of the electrons and the oxygen in the air undergo a reduction reaction on the side of the reduction catalyst layer 2 on the back surface of the filter 19 to generate a superoxide ion. When ions are generated and the room air passes through the filters 19 of the intake-side inlet 21 and the exhaust-side outlet 22, odorous substances in the air, cigarette smoke, or sick house syndrome Cause like formaldehyde and toluene as the efficient oxidized in the filter 19 both sides, it is degraded.

It is preferable that the filter 19 be detachably attached to the casing 23 of the air purifier 20 so that the filter 19 can be removed and washed with water when the filter 19 becomes clogged.

FIG. 7 shows a substrate 1 having a wire diameter of 0.15
A 40-mesh net formed by knitting a stainless steel wire rod having a thickness of 25 mm, a photocatalyst member 4 having a photocatalyst layer 4 formed on the front side and a reduction catalyst layer 2 such as platinum formed on the back side is formed in a filter 19 shape. This shows an example in which this is installed in a defroster section 27 of a passenger car 26.

The filter 19 is, for example, removably attached to a suction cup (not shown) on the windshield 28 so that the blown air passes through the filter 19.

When the filter 19 is irradiated with the sun rays whose ultraviolet rays have been cut through the windshield 28, hydroxy radicals and superoxide ions are deposited on the photocatalyst layer 4 on the front side and the reduction catalyst layer 2 on the back side. When the air blown out from the defroster section 27 passes through the filter 19, odorous substances and smoke of cigarettes are oxidized and decomposed by these.

FIG. 8 shows a 50-mesh net formed by knitting a stainless steel wire having a wire diameter of 0.1 mm as a base material 1, a photocatalyst layer 4 on the front side, and a reduction of platinum or the like on the back side. The photocatalyst member having the catalyst layer 2 formed thereon is
The filter 19 is formed into a 9-shape,
This is an example of use as a deodorizing and sterilizing device in a freezing / refrigerating facility 30 such as a refrigerator car, a freezing warehouse, a refrigerator, etc.

In this example, the air in the space of the freezing / refrigeration equipment 30 is circulated by the fan 24 installed in the duct 31, and the filter 19 is provided at the inlet and the outlet of the duct 31, and the photocatalyst layer 4 side is the indoor surface. Is provided so that the reduction catalyst layer 2 side faces the back surface.

A lighting fixture 25 such as a fluorescent lamp or an incandescent lamp for illuminating the inside of the space is provided on the ceiling of the freezing / refrigeration equipment 30.
Irradiates with the visible light emitted by.

The photocatalyst layer 4 on the surface is generated by holes and electrons excited by the photocatalyst layer 4 on the surface side of the filter 19 by visible light, particularly light rays up to a wavelength region near 550 nm, which are generated when the lighting equipment 25 is turned on. On the side, the holes react with water contained in the atmosphere to produce hydroxyl radicals, and a part of the electrons react with oxygen in the atmosphere to produce superoxide ions. Some of the electrons react with oxygen in the atmosphere to generate superoxide ions, and odorous substances and bacteria in the circulating air are oxidized on both surfaces of the filter member 19 and decomposed and sterilized.

In this way, it is sterilized and deodorized by a fluorescent lamp or an incandescent lamp which illuminates the inside without using an ultraviolet lamp, and the perishable food does not discolor like an ultraviolet lamp. It is possible to prevent sunburn or the like caused by ultraviolet irradiation on persons working in the vehicle, and the effect is enormous.

As described above, the photocatalyst layer is provided on one surface,
By providing a catalyst layer on the other surface and passing air through this filter, odorous substances and harmful substances are decomposed on both the photocatalyst layer side excited by light irradiation and the catalyst layer side not irradiated with light, and the effect is improved. Double.

FIG. 9 shows an example of a garbage can 32 having a 0.5 mm thick stainless steel plate as the substrate 1 and a photocatalyst layer 4 provided on the outer surface side and a reduction catalyst layer 2 provided on the inner side.
Even if visible light is not inserted into the inside of the garbage, when visible light shines on the outer surface, some of the electrons and oxygen in the air undergo a reduction reaction in the reduction catalyst layer 2 on the inner surface side of the trash can 32 to generate superoxide ions, Odor substances in the trash bin 32 are decomposed or sterilized.

As a matter of course, the outer surface of the trash box 32 is also decomposed or sterilized by the photocatalytic layer 4 so that an extremely sanitary trash box 32 can be provided.

FIG. 10 shows a case where a stainless steel plate having a thickness of 1 mm is used as the base material 1, a photocatalyst layer 4 is provided on the front side, and a reduction catalyst layer 2 is provided on the back side. This is an example in which the photocatalyst layer 4 is processed on the surface side of the water washer 33 by room lighting or sunlight.
Is photo-excited to generate hydroxyl radicals and superoxide ions on the surface of the washer 33, and the resulting antibacterial action decomposes slime and dirt attached to the surface of the washer 33 and reduces the catalyst layer exposed in the cabinet 34. On the second side, superoxide ions are generated, whereby the odorous substances in the air in the cabinet 34 are decomposed or sterilized, and there is no need to install a deodorant or a germicidal lamp in the cabinet 34.

The present invention can be variously modified without being limited to the above-described embodiment.
A member that can withstand the heat treatment temperature such as a metal such as iron may be used, and the thickness of the base material, the thickness of the wire, and the like are also arbitrary.

The catalyst layer of platinum or the like can be laminated on a substrate by a dry coating method such as an electron beam method or an ion plating method, a platinum plating method, a cladding method, etc. other than the sputtering method. Etc. can also be used.

Of course, after a catalytic substance such as platinum is coated on both sides of the substrate, a photocatalyst layer may be formed on one side of the substrate. A catalytic substance such as platinum may be coated.

As a method of dry coating a TiO2 thin film, an electron beam method, a hollow cathode method, or the like may be used in addition to the sputtering method and the ion plating method.

Further, Ti, TiO, Ti2O3, Ti3O5 or the like may be used as the target member of the TiO2 thin film, and oxygen may be supplied near the base material to oxidize the target member.

Further, the reduction catalyst layer is not always necessary. Particularly, in the case of an anatase type crystal structure, the photoactivity is high,
Although it is not necessary to provide the reduction catalyst layer, it is preferable to provide the reduction catalyst layer on the back side of the photocatalyst layer because oxidation and reduction reactions occur on both the front and back surfaces, but the catalyst is preferably provided on the same side as the photocatalyst layer, for example, on the periphery. A layer may be provided.

The thickness of the catalyst layer only needs to be about 1 to 5 nm, and the effect does not change even if the catalyst layer is made thicker. However, platinum or the like is extremely expensive, and increasing the thickness only increases the production cost.

Further, if the photocatalyst layer has a thickness of about 200 nm to about 1000 nm, the function can be sufficiently exhibited. Further, a small amount of transition metal ions such as Cr and V is injected into the photocatalyst layer to improve the efficiency of the photocatalytic reaction. May be.

Further, in the heat treatment, parameters such as heating conditions, a predetermined time, an oxygen concentration atmosphere, and a temperature drop condition during rapid cooling are changed to select an anatase type or rutile type crystal structure, and to set an X value of TiOx. To set the visible light absorption region.

If the heating temperature is higher than 1,000 ° C., the surface of the crystal structure becomes rough and hard to activate, and the room for selection of the base material becomes narrower. If the temperature is lower than 450 ° C., the crystal structure becomes amorphous. And is not activated.
It is preferred to heat at 50 to 1,000 ° C.

When a net is used as a base material and a filter is used, it is used for purifying an aquarium or a lake which is hard to transmit ultraviolet rays, removing harmful substances such as dioxin contained in exhaust gas from an incinerator, and coating equipment. It can be used for many purposes such as removal of organic solvent contained in exhaust gas, removal of odor when combustion of household fan heaters is stopped, screen doors, and cages at garbage collection sites.

Further, the photocatalyst member of the present invention can be used for a solar cell.

[0070]

As described above, the photocatalyst member and the method of manufacturing the same according to the present invention are characterized in that the substrate surface is dry-coated with a TiO2 thin film, heated in an atmosphere of about 450 to 1,000 ° C. for a predetermined time and then rapidly cooled. In a simple method such as forming a photocatalyst layer, when heated at about 450 ° C. for about 10 to 20 hours and quenched, about 700 to 1,0 of anatase type is obtained.
When heated and quenched at 00 ° C. for about 1 to 3 hours, TiOx having rutile-type oxygen defects (X is 1.99 <X <2
The photocatalyst layer having a yellow tint can be formed, and its thickness can be easily controlled. In addition, it can be mass-produced in a temperature range where ordinary metals and the like do not melt and can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic view showing steps of a method for producing a photocatalyst member of the present invention.

FIGS. 2A and 2B are cross-sectional views based on a manufacturing process, wherein FIG. 2A is a cross-sectional view in which a reduction catalyst thin film is coated on the back surface of a conductive plate-like base material such as a stainless steel plate, and FIG. FIG. 3C is a cross-sectional view after heating and quenching the substrate to form a photocatalytic layer.

FIG. 3 is a graph showing an energy potential.

FIG. 4 is a schematic view of an apparatus for coating a substrate with a reduction catalyst and TiO 2.

FIG. 5 is a schematic view of another apparatus for coating a substrate with a reduction catalyst and TiO2.

FIG. 6 is a schematic diagram showing an example in which a photocatalyst member is applied to a filter member and used in an air purifier.

FIG. 7 is a schematic view showing an example in which a photocatalyst member is applied to a filter member and used in a car.

FIG. 8 is a schematic diagram showing an example in which a photocatalyst member is applied to a filter member and used in a refrigerator / refrigeration facility.

FIG. 9 is a schematic view showing an example in which a photocatalyst member is applied to a plate material and used as a trash can.

FIG. 10 is a schematic view showing an example in which a photocatalyst member is applied to a plate material and used in a water washer.

[Explanation of symbols]

 A: Step of coating a reduction catalyst layer on a substrate B: Step of coating a TiO2 thin film on a substrate C: Step of heating for a predetermined time D: Step of rapidly cooling to form a photocatalyst layer 1: Base 2: Reduction catalyst layer 3: TiO2 thin film 4: photocatalytic layer 5: first sputtering chamber 6: second sputtering chamber 7: supply drum 8: intermediate drum 9: intermediate drum 10: winding drum 11: ion plating chamber 12: electron gun 13 : Setting chamber 14: Roller 15: Roller 16: Drum 17: Crucible 18: Oxygen supply source 19: Filter 20: Air purifier 21: Inlet 22: Outlet 23: Casing 24: Fan 25: Lighting equipment 26: Passenger car 27: Defroster Part 28: windshield 29: fresh food 30: frozen / cold Facilities 31: duct 32: Trash 33: washing device 34: Cabinet

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F24F 7/00 F24F 7/00 A F25D 23/00 302 F25D 23/00 302M // A61L 9/18 A61L 9/18 F Terms (reference) 4C080 AA07 BB02 BB04 BB05 CC02 CC12 CC15 HH05 JJ03 KK08 LL02 MM02 QQ03 4G069 AA08 AA11 BA04A BA04B BA48A BC75B CA08 CA17 DA05 EA08 EC22Y EE01 EE08 FA03 FB02 FB30 FB30FB37FB37

Claims (5)

[Claims] 1. A photocatalyst member wherein a photocatalyst layer is formed by dry-coating a TiO2 thin film on the surface of a substrate, heating it in an atmosphere at about 450 to 1,000 ° C. for a predetermined time, and then quenching it. 2. The method according to claim 1, wherein the base material is made of a conductive material, and a reduction catalyst layer for promoting a reduction reaction of electrons generated by photoexcitation of the photocatalyst layer is formed on a back surface thereof.
The photocatalyst member as described in the above. 3. The photocatalyst member according to claim 1, wherein the base material is a metal net material. 4. A method for producing a photocatalyst member, wherein a photocatalyst layer is formed by dry coating a TiO2 thin film on the surface of a conductive substrate, heating in an atmosphere of about 450 to 1,000 ° C. for a predetermined time, and then quenching. Method. 5. The method for producing a photocatalyst member according to claim 4, wherein a reduction catalyst layer for promoting a reduction reaction of electrons generated by photoexcitation of the photocatalyst layer is formed on the back surface of the base material.