KR102184694B1 - Air Cleaning Filter Using Visible Light Excitation Photocatalyst and Manufacturing Method Thereof - Google Patents

Abstract

Disclosed is an air cleaning filter using a double-layered visible light-excited photocatalyst capable of sterilizing harmful gas decomposition and harmful bacteria and removing fine dust. This can sterilize harmful gas decomposition and harmful bacteria by harmful air introduced into the body by forming a photocatalytic material inside and outside the body formed of a double layer, and effectively remove fine dust. In addition, by forming a photocatalyst capable of excitation with visible light inside and outside the main body, and irradiating the formed photocatalyst with visible light, it is possible to secure stability compared to the conventional ozone method or ultraviolet method, which is controversial as harmful to the human body. Compared to the method, initial investment and maintenance cost can be reduced.

Description

Air Cleaning Filter Using Visible Light Excitation Photocatalyst and Manufacturing Method Thereof}

The present invention relates to an air cleaning filter using a visible light-excited photocatalyst and a method for manufacturing the same, and more particularly, to an air using a visible light-excited photocatalyst capable of decomposing harmful gases and sterilizing harmful bacteria and removing fine dust. It relates to a clean filter.

With the recent increase in environmental pollution, the harmfulness of the human body due to air pollution is also increasing day by day, and air pollution, which accounts for most of the environmental pollution, pollutes not only the outdoor air but also the indoor air where people are active for a long time. In particular, it is known that ultra-fine dust with a level of PM 2.5M or less, mainly generated from automobile exhaust gas, penetrates deep into the respiratory tract of the human body, attaches to the lung tissue, causes respiratory disease, and is absorbed into the blood vessels, causing stroke or heart disease.

In order to purify such contaminated air with clean air, air purifiers are widely used, and the air purifier inhales contaminated air with a blower to collect fine dust or bacteria by means of a filter means, or with a dust removal function. It performs the function of odor, harmful gas, and deodorization.

As the air cleaning method, there are various methods such as an ozone method, a photocatalytic method using ultraviolet rays, a method using plasma, and a high temperature heat treatment method.

However, the ozone method and the method using ultraviolet rays have been controversial about harm to the human body, and the method using plasma or the high temperature heat treatment method has a disadvantage of high initial investment and maintenance cost.

Korean Patent Registration 10-0750993

The technical problem to be achieved by the present invention is to provide an air cleaning filter and a manufacturing method thereof using a visible light-excited photocatalyst capable of sterilizing harmful gas decomposition and harmful bacteria by irradiating visible light on a photocatalyst layer formed of a double layer, and removing fine dust. It is in providing.

The air cleaning filter using the visible light-excited photocatalyst of the present invention for solving the above problem includes a body having an empty inside so that outside air is introduced, a light source unit for irradiating light into the body, and formed outside the body, and the light source unit A first filter unit that is reacted or activated by light incident by the light to remove fine dust, is formed inside the body so as to contact the first filter unit, and is reacted or activated by light incident on the light source unit to be harmful. It includes a second filter for decomposing gas and sterilizing harmful bacteria.

The body may have a cylindrical shape with an empty inside.

The body may be formed of any one of a HEPA filter, a carbon filter, and a pre-filter.

The body may be formed in a double-layer structure having different fiber diameters.

The first filter part is made of polyethylene terephthalate (PET) having a fiber diameter of 30 μ to 50 μm, and the second filter part is made of polypropylene (PP) having a fiber diameter of 3 μ to 5 μm. Can be formed.

The light source unit may include a light source for emitting light, a lens for irradiating the light emitted from the light source into the body, and a heat sink for supporting the light source and the lens and radiating heat generated from the light source.

The lens may have a hemispherical shape.

The lens may include a first groove formed at a lower center of the lens and a second groove formed at an upper center of the lens.

The first groove and the second groove may be formed in a hemispherical shape.

The light source unit may be disposed inside the body so that the lens faces the inside of the body, and the lower surface of the heat sink may be disposed to be the same surface as one side surface of the body.

The light emitted from the light source unit may be visible light.

The visible light may have a wavelength range of 400 nm to 410 nm having a sterilizing effect.

Each of the first filter unit and the second filter unit may further include a photocatalytic material coated on a surface.

The photocatalytic material may include any one of TiO ₂ , ZnO, SnO ₂ , WO ₃ , ZnS, NiO and Fe ₂ O ₃ materials.

The photocatalytic material may be formed of a material doped with a metal ion in a chalcogenide.

The photocatalytic material is TiO ₂ Formed of a material, and the TiO ₂ is TiO ₂ Transition metals of V, Cr, Mn, Fe, Co, Ni, Cu, and Zn or non-metal ions of B, C, N, and F may be doped in the inside to form through band gap control.

The chalcogenide is CuInGaSe ₂ , Cu ₂ ZnSnS ₄ It includes any one of materials, and the metal ion may include any one of Ag, Pt, and Au materials.

It may further include a fan disposed below the main body and introducing external air into the main body.

The method of manufacturing an air cleaning filter using a visible light-excited photocatalyst of the present invention for solving the above problems includes preparing a liquid photocatalyst material, coating the liquid photocatalyst material on a filter fabric formed of a double layer, and the liquid photocatalyst material And chemically reducing the coated filter fabric using a chemical reduction method, and folding the reduced filter fabric at regular intervals to form a cylindrical structure, and disposing a light source in the cylindrical filter fabric.

The preparing of the liquid photocatalyst material includes mixing titanium tetraisopropoxide (TTIP) and a solvent, forming a sol-gel solution by mixing the mixture with ultrapure water (DI), and hydrothermal synthesis of the sol-gel solution. And forming a liquid photocatalytic material using a process.

The solvent may include isopropyl alcohol (IPA) and glacial acetic acid (AA).

The mixing molar ratio to 1 mole of the titanium tetraisopropoxide (TTIP) for forming the liquid photocatalytic material may be TTIP: IPA: AA: DI = 1: 1-5: 3-12: 100.

The double layer is formed on the outside of the filter fabric, the first filter part formed of polyethylene terephthalate (PET) having a fiber diameter of 30 μ to 50 μ and is formed on the inside of the filter fabric, It may include a second filter unit formed of polypropylene (PP) having a diameter of 3 μ to 5 μ.

The chemical reduction treatment step includes dissolving hydrochloric acid in ultrapure water to form a reducing solution, mixing the reducing solution with sodium borohydride (NaBH ₄ ), and a filter fabric coated with the photocatalytic material in the mixture. It may include a step of immersion.

The sodium borohydride (NaBH ₄ ) for the chemical reduction treatment may be a molar ratio of 1 mole to the compounding molar ratio of NaBH ₄ : H ₂ O: HCl = 1: 3-10: 0.8-2.

The light source unit includes a light source that emits light, a lens formed in a hemispherical shape, and a heat sink configured to radiate heat generated from the light source and radiate heat generated from the light source. Can include.

According to the present invention, by forming a photocatalytic material inside and outside a body formed of a double layer, it is possible to sterilize harmful gas decomposition and harmful bacteria by harmful air flowing into the body, and effectively remove fine dust.

In addition, by forming a photocatalyst capable of excitation with visible light inside and outside the body, and irradiating visible light to the formed photocatalyst material, it is possible to secure stability compared to the conventional ozone method or ultraviolet method, which is controversial as harmful to the human body.

In addition, since it is possible to sterilize harmful gas decomposition and harmful bacteria by using visible light of around 405nm, which has a sterilizing effect, and effectively removes fine dust, the initial investment and maintenance cost can be reduced compared to the conventional plasma or high temperature heat treatment method. There is an advantage to be able to.

In addition, it is possible to improve the excitation performance by visible light by performing a chemical reduction treatment on the body coated with the photocatalytic material.

Furthermore, by forming the lens of the light source unit in a hemispherical shape, light emitted by the light source can be uniformly irradiated onto the inner wall surface of the main body.

The technical effects of the present invention are not limited to those mentioned above, and other technical effects that are not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a view showing an air cleaning filter using a visible light-excited photocatalyst of the present invention.
2 is an image showing a double layer structure of a main body according to the present invention.
3 is a view showing a light source unit according to the present invention.
4 is a view showing the direction of light travel according to the lens of the present invention.
5 is a graph showing the optical measurement result according to the lens of the present invention.
6 is a flow chart showing a method of manufacturing an air cleaning filter using a visible light-excited photocatalyst of the present invention.
7 is an image showing before and after a photocatalytic material is coated on the air cleaning filter of the present invention.
8 is an image showing an air cleaning filter according to a manufacturing example of the present invention.
9 is an image showing an experiment result according to a comparative example of the present invention.

Since the present invention can apply various transformations and have various embodiments, specific embodiments are illustrated in the drawings and will be described in detail in the detailed description. However, this is not intended to limit the present invention to a specific embodiment, it is to be understood to include all conversions, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, identical or corresponding components are assigned the same reference numbers, and redundant descriptions thereof will be omitted. To

1 is a view showing an air cleaning filter using a visible light-excited photocatalyst of the present invention.

Referring to FIG. 1, an air cleaning filter using a visible light-excited photocatalyst according to the present invention includes a body 100, a light source unit 200, a first filter unit 110 and a second filter unit 120.

The body 100 may be formed in various pillar shapes such as a cylindrical shape, a square pillar shape, a triangular pillar shape, etc., but the cylinder It is preferable that the inside of the shape is formed in an empty cylindrical shape.

The body 100 may be formed of any one of a HEPA filter, a carbon filter, and a pre-filter, and may have a double layer structure. In more detail, the main body 100 may be formed of a HEPA filter in a cylindrical shape, and the cylindrical shape may be formed in a double-layer structure formed by combining layers having different diameters. That is, the layers forming the inner and outer sides of the cylinder may be formed of fibers having different diameters.

Here, the outside of the main body 100 is formed of a first filter unit 110 that is reacted or activated by light incident by the light source unit 200 to remove fine dust flowing into the main body 100, and the main body ( The inside of 100) is formed on the inside of the main body 100 so as to come into contact with the first filter unit 110, and is reacted or activated by incident light to decompose harmful gases flowing into the main body 100 and decompose harmful bacteria. It may be formed of a second filter unit 120 to sterilize. That is, the main body 100 according to the present invention may be a cylindrical air cleaning filter in which the first filter unit 110 and the second filter unit 120 are formed as a double layer.

2 is an image showing a double layer structure of a main body according to the present invention.

Here, FIG. 2(a) is an image showing the first filter unit 110 formed on the outside of the main body 100, and FIG. 2(b) shows the second filter unit 120 formed on the inside of the main body 100. This is the image shown.

Referring to FIG. 2, as an embodiment, the first filter unit 110 of the main body 100 is formed of polyethylene terephthalate (PET), and the second filter unit 120 is polypropylene. It may have a double layer structure formed of PP). Preferably, the first filter unit 110 may be formed of PET having a diameter of 30 μm to 50 μm, and the second filter unit 120 may be formed of PP having a diameter of 3 μm to 5 μm. have. That is, external air flowing into the main body 100 from the outside passes through the first filter unit 110 formed of PET on the outside of the double-layer structure, and passes through the second filter unit 120 formed of PP on the inside, and the main body 100 ) It can flow inside.

In addition, the first filter unit 110 and the second filter unit 120 according to the present invention may include a photocatalytic material coated on the surface of the filter unit. That is, light irradiated from the light source unit 200 is irradiated with the photocatalytic material coated on the first filter unit 110 and the second filter unit 120, respectively, so that the photocatalytic material may be reacted or activated.

Accordingly, the first filter unit 110 formed on the outside of the double layer structure can function as a filtration layer for removing fine dust, and the second filter unit 120 formed on the inside functions to decompose harmful gases and sterilize harmful bacteria. It can function as a layer.

That is, the air cleaning filter according to the present invention has an effect of simultaneously removing not only fine dust but also harmful gases and harmful bacteria by the two filters 110 and 120 formed in a double layer structure. The photocatalytic material formed in the first filter unit 110 and the second filter unit 120 will be described in detail below.

Subsequently, the light source unit 200 irradiates the light emitted from the light source unit 200 into the body 100. That is, the light source unit 200 provides light required for activation of the photocatalytic material coated on the first filter unit 110 and the second filter unit 120 of the main body 100, thereby decomposing harmful gases and sterilizing harmful bacteria. Let it happen.

3 is a view showing a light source unit according to the present invention.

4 is a view showing the direction of light travel according to the lens of the present invention.

1, 3, and 4, the light source unit 200 according to the present invention includes a light source 210 that emits light, and a lens 220 disposed to uniformly irradiate the emitted light into the body 100. And a heat sink 230 for dissipating heat generated by the light source 210.

The light source 210 is formed of, for example, a light source 210 such as a 254 nm sterilizing lamp that emits light, a UV-A UV lamp, and a UV-C, -A band LED, and may include visible light having a sterilizing effect. have. In more detail, the visible light of the present invention may be visible light in a wavelength range of 400 nm to 410 nm, and preferably 405 nm to activate the photocatalytic material coated on the body 100 to decompose harmful gases and sterilize harmful bacteria. It may be visible light having a wavelength of.

As the light source 210 for activating the photocatalytic material by irradiating light as described above, various methods such as an ozone method, a photocatalytic method using ultraviolet rays, a method using plasma, and a high-temperature heat treatment method have been used, but the ozone method and the ultraviolet ray are used. As for the method, controversy about harm to the human body has been raised, and the method using plasma or the high temperature heat treatment method has a disadvantage of high initial investment and maintenance cost.

However, the air cleaning filter of the present invention can secure stability compared to the conventional ozone method or ultraviolet method, which is controversial to human health by using visible light of 400 nm to 410 nm. In addition, since it is possible to sterilize harmful gas decomposition and harmful bacteria by using visible light of around 405nm, which has a sterilizing effect, and effectively removes fine dust, the initial investment and maintenance cost can be reduced compared to the conventional plasma or high temperature heat treatment method. There is an advantage to be able to.

The lens 220 of the light source unit 200 may be disposed to house the light source 210. That is, the light source 210 may be surrounded by the lens 220 so that the light emitted from the light source 210 is irradiated to the outside through the lens 220. In more detail, the light source 210 is connected to the heat sink 230 for dissipating heat generated from the light source 210, and the lens 220 has the light source 210 disposed below the center of the lens 220 It may be disposed on the heat sink 230 as possible.

As shown in FIG. 1, the light source unit 200 may be disposed inside the body 100 having a cylindrical shape. That is, the light source unit 200 is disposed inside the body 100 so that the lens 220 disposed on the heat sink 230 faces the inside of the body 100, and the heat sink 230 of the light source unit 200 is the body 100 It may be arranged to be the same side as the lower side of the. Therefore, the light irradiated from the light source unit 200 may be irradiated only in the inner direction of the cylinder.

In this case, the lens 220 may have a hemispherical shape as shown in FIG. 3 so that light emitted from the light source 210 is irradiated only to the inner wall of the main body 100 through the lens 220.

That is, since the lens 220 according to the present invention has a hemispherical shape, light irradiated from the light source 210 to the inner wall of the main body 100 passes through the hemispherical lens 220 and transmits light toward the inner wall of the main body 100. It can be concentrated, and the light irradiated to the inner wall of the main body 100 can be uniformly distributed.

In addition, the hemispherical lens 220 may include a first groove 221 formed in an upper direction at a lower center and a second groove 222 formed in a lower direction at an upper center. Here, the first groove 221 and the second groove 222 have a hemispherical shape, and may be formed to have a size of the second groove 222 larger than the size of the first groove 221.

The first groove 221 may provide a space in which the light source 210 is disposed so that the light source 210 is disposed at the lower center of the lens 220, and the light irradiated from the light source 210 is the first groove 221 Through the lens 220 may be irradiated toward the outer wall.

The second groove 222 may function such that light irradiated from the light source 210 in the longitudinal direction of the main body 100 through the lens 220 is refracted toward the inner wall of the main body 100. That is, as shown in FIG. 4, light irradiated in a direction other than the center of the hemispherical shape is irradiated in the direction of the inner wall of the main body 100, and irradiated in the direction of the center of the hemispherical shape, The light is refracted by the second groove 222 to change the direction of the light toward the inner wall of the body 100. Accordingly, the lens 220 according to the present invention may have a hemispherical shape and a second groove 222 formed in the upper center of the hemispherical shape to focus light on the inner wall of the cylindrical body 100.

5 is a graph showing the optical measurement result according to the lens of the present invention.

Referring to FIG. 5, it can be seen that the intensity of light increases toward the top of the hemispherical shape, and the intensity of light is lowest at the center of the upper portion where the groove 221 is formed. That is, when the lens 220 is disposed at the center of the lower portion of the body 100 formed in a cylindrical shape and irradiated with light, the inner wall of the main body 100 farther from the lens 220 than the inner wall of the main body 100 close to the lens 220 Since the intensity of light directed to it is large, the inner wall of the main body 100 can be uniformly irradiated by the lens 220. In addition, light directed to the center of the cylinder is blocked by the second groove 222 formed in the upper center of the lens 220, so that the light is concentrated on the inner wall of the main body 100 so that the light irradiated to the inner wall of the main body 100 is prevented. It can be distributed evenly.

In addition, a fan 300 that applies a negative pressure so that external air is introduced into the body 100 may be further included in the upper or lower part of the main body 100. Accordingly, external air containing harmful gases or harmful bacteria may be introduced into the body 100 by the fan 300, and the introduced external air is irradiated from the light source unit 200. ) Can be decomposed or sterilized by reacting or activating the coated photocatalytic material.

Subsequently, referring to FIG. 1, in the air cleaning filter according to the present invention, a photocatalytic material may be coated on each of the first filter unit 110 and the second filter unit 120 formed of a double layer.

As an embodiment, in the double layer structure of the main body 100 formed of a cylinder, a first filter unit 110 formed of PET having a diameter of 3 μm to 5 μm and a second filter unit 120 formed of PP having a diameter of 30 μm to 50 μm Each photocatalytic material may be coated on the surface. During coating, the photocatalytic material is evenly coated on the surfaces of the filter units 110 and 120, but nanorods may be additionally grown to increase the reaction specific surface area.

Here, the photocatalytic material formed in the first filter unit 110 and the second filter unit 120 may be formed of a photocatalytic material that is reacted or activated by visible light irradiated from the light source unit 200. More specifically, it may be formed of a material that reacts or is activated to visible light in the wavelength range of 400 nm to 410 nm, which has a sterilizing effect against harmful gases and harmful bacteria, and more preferably reacts or activates to visible light in the 405 nm band. It can be formed of a material.

For example, when a living bacteria is irradiated with visible light in the 405nm band, it stimulates the porphyrin molecules present in the bacteria to inactivate the cells, and eventually creates intracellular reactive oxygen species (ROS) that can destroy them. do. The active oxygen thus generated may be processed by irradiating visible light of a 405 nm band to the photocatalytic material coated on the first filter unit 110 and the second filter unit 120.

Accordingly, the photocatalytic material coated on the first filter unit 110 and the second filter unit 120 of the present invention may be coated with a material that reacts or activates the visible light of the 405 nm band irradiated from the light source unit 200.

As an example, the photocatalytic material formed in the first filter unit 110 and the second filter unit 120 is TiO ₂ , ZnO, SnO ₂ , WO ₃ , ZnS, NiO and Fe ₂ O ₃ excitable in visible light of a 405 nm band. It may contain any one of the substances. The photocatalytic material is a photocatalyst that is coated on the entire inner and outer walls of the main body 100 to generate electron-holes on the metal surface by the light irradiated from the light source unit 200, and they react with hydroxyl groups (H ₂ O) in the air. To generate a hydroxide radical (OH). This hydroxide radical (OH) is a very strong oxidizing agent and can be responsible for sterilization and decomposition of various kinds of organic compounds.

As an example, the photocatalytic material coated on the first filter unit 110 and the second filter unit 120 according to the present invention is preferably formed of TiO ₂ . The TiO ₂ The substance is TiO ₂ Transition metals of V, Cr, Mn, Fe, Co, Ni, Cu, and Zn or non-metal ions of B, C, N, and F may be doped in the inside to form through band gap control.

In addition, it is possible to improve the excitation performance of visible light irradiated to the main body 100 by chemical reduction of the photocatalytic material on the photocatalytic material coated on the first filter unit 110 and the second filter unit 120 as described above. have.

As an example, hydrogenation of the TiO ₂ photocatalyst layer coating process the manufacturing of TiO ₂ to the first filter unit 110 and the second filter 120, by using a chemical reducing agent as described above, as a photocatalyst TiO _{2 - x} By forming the H _x photocatalyst layer, it is possible to improve the absorbance in the visible light band. Here, sodium borohydride (NaBH ₄ ) may be used as the chemical reducing agent used for the chemical reduction treatment.

As another embodiment, the photocatalytic material formed in the first filter unit 110 and the second filter unit 120 may be formed of a material doped with metal ions in chalcogenide. Here, the chalcogenide material is CuInGaSe ₂ (CIGS), Cu ₂ ZnSnS ₄ (CZTS) It may include any one of the materials, and the metal ion may include any one of Ag, Pt, and Au materials. Preferably CuInGaSe ₂ (CIGS), Cu ₂ ZnSnS ₄ (CZTS) It can be formed by doping Ag on any one of the materials.

For example, increasing the photocatalytic efficiency in the visible light band by reducing the band gap by doping with transition metals or non-metal ions can be responsible for sterilization and decomposition of various types of organic compounds, but this promotes electron-hole recombination. When the recombination of electrons and holes is promoted, the photocatalyst efficiency decreases. Accordingly, in order to prevent the disadvantage of deteriorating photocatalytic efficiency due to the recombination of electrons and holes, recombination of electrons and holes may be suppressed by doping with noble metal ions as described above.

The photocatalyst material can be excited not only in visible light but also in the ultraviolet band of less than 400 nm, but the ultraviolet method has a sterilizing effect and has a sterilizing effect as compared to the conventional ultraviolet method and ozone method, since controversy about harmfulness to the human body arises as described above along with the ozone method. It is more preferable to use visible light in the 405 nm band that can ensure stability. Therefore, the first filter unit 110 and the second filter unit 120 according to the present invention are reacted or activated by the visible light of the 405 nm band emitted from the light source unit 200 to enter the main body 100 from the outside. It can remove dust, decompose harmful gases and sterilize harmful bacteria.

6 is a flow chart showing a method of manufacturing an air cleaning filter using a visible light-excited photocatalyst of the present invention.

6, the method of manufacturing an air cleaning filter using a visible light-excited photocatalyst according to the present invention includes preparing a liquid photocatalyst material (S310), and coating the liquid photocatalyst material on a filter fabric formed as a double layer (S320). ), chemical reduction treatment of the filter fabric coated with the liquid photocatalytic material using a chemical reduction method (S330), and the filter fabric having the reduction treatment is folded at regular intervals to form a cylindrical structure, and a light source unit in the filter fabric having the cylindrical structure It includes the step of arranging (S340).

The manufacturing method of the air cleaning filter using the visible light-excited photocatalyst will be described in detail through the following manufacturing example.

Preparation Example 1 ( Preparation of visible light-excited liquid photocatalyst material)

In the first step, 11.5 mL of titanium tetraisopropoxide (TTIP) and 20 mL of glacial acetic acid (AA) are sequentially added to 3 mL of isopropyl alcohol (IPA) and mixed. When the mixing is complete, as a second step, the mixed solution is added dropwise to 70 mL of ultrapure water (DI) to form a sol-gel solution. In the third step, put the formed sol-gel solution in a 100 mL Teflon container, put the container containing the sol-gel solution in a stainless steel hydrothermal synthesizer, and raise it to 150°C at a rate of 3°C/min at room temperature, and 1.5 at 150°C. Keep time. After that, a liquid photocatalyst material is prepared by performing a hydrothermal synthesis process of naturally cooling to room temperature.

Here, the reaction scheme for preparing the liquid photocatalyst material can be represented by the following <Reaction Scheme 1> and <Reaction Scheme 2>.

<Reaction Scheme 1>

<Reaction Scheme 2>

In addition, titanium tetra isopropoxide (TTIP): isopropyl alcohol (IPA): glacial acetic acid (AA): ultrapure water (DI) = 1: 1-5: 3 when preparing a liquid photocatalyst material ~12: It is preferable to form so as to be 100. If the molar ratio of isopropyl alcohol (IPA) to 1 mole of isopropoxide (TTIP) is lower than 1, the coating solution concentration is low, so the workability is not good. Because it doesn't work. In addition, if the molar ratio of glacial acetic acid (AA) to 1 mole of isopropoxide (TTIP) is lower than 3, the pH of the coating solution is high, so that the coating thickness is not uniformly thick when coating the fiber surface, resulting in a problem of peeling. If it is higher than 12, the pH of the coating solution is too low, and the coating amount may be insufficient to be less than the uniform coating level.

Preparation Example 2 (Air cleaning filter coating using liquid photocatalytic material)

A HEPA filter fabric having a double-layered inner side spun with polypropylene (PP) fibers having a diameter of about 4 μm and an outer spun with a diameter of 40 μm polyethylene terephthalate (PET) fibers is prepared. The prepared filter fabric is washed with ultrapure water (DI) and a detergent, dried naturally, immersed in a liquid photocatalyst material for 10 minutes, and then dried at room temperature. When drying is complete, vacuum drying at 70° C. for 3 hours, DI washing and vacuum drying are performed to complete the coating of the air cleaning filter using the liquid photocatalyst material.

7 is an image showing before and after a photocatalytic material is coated on the air cleaning filter of the present invention. Here, Fig. 7(a) shows the fiber state of the fabric before coating, and Fig. 7(b) shows the fiber state of the fabric after coating. That is, as shown in FIG. 7(b), it can be seen that the photocatalytic material is coated on the fiber surface at a nano level.

Preparation Example 3 (Chemical Reduction Treatment of Photocatalytic Substance)

In the first step, 50 mL of 37v.% hydrochloric acid is dissolved in 500 mL of ultrapure water to form a reducing solution. In the second step, 100 g of sodium borohydride (NaBH ₄ ) is added to a 1 L Teflon container, and the reduction solution is added thereto. In the third step, the Teflon container to which the reducing solution and sodium borohydride (NaBH ₄ ) are added is put in an air cleaning filter fabric coated with a certain amount of TiO ₂ photocatalytic material, and then the Teflon container is pressurized and sealed. The sealed container is opened after 1 hour, the fabric is removed, washed in ultrapure water, and vacuum dried. By the chemical reduction treatment of such a photocatalytic material, an air cleaning filter fabric with improved visible light excitation performance can be implemented.

The reaction formula for the preparation of the chemical reduction treatment of such a photocatalytic material can be represented by the following <Scheme 3> to <Scheme 5>.

<Reaction Scheme 3>

<Reaction Scheme 4>

<Reaction Scheme 5>

In addition, when preparing a chemical reduction solution, it is preferable that sodium borohydride (NaBH4): ultrapure water (H2O): hydrochloric acid (HCl) = 1: 3-10: 0.8-2 is formed as an appropriate mixing ratio (mol.) . This means that if the molar ratio of ultrapure water (H ₂ O) to 1 mole of sodium borohydride (NaBH ₄ ) is lower than 3, the amount of the reducing agent to be immersed is not enough to be immersed, but also the amount of HCl is relatively excessive, so NaBH ₄ Because the reaction with (NaBH ₄ (s) + HCl(aq) + 3H ₂ O(aq) → NaCl(aq) + H ₃ BO ₃ (aq) + 4H ₂ (g)) is accelerated, the generation of H ₂ occurs rapidly. textile coated is a problem that can not be performed had a reaction of TiO ₂ can be generated, and higher than 10, reaction with _{NaBH 4 (NaBH 4 (s)} + 2H 2 O (l) → NaBO 2 (aq) + 4H 2 ( g)) is relatively too slow, so that the amount of hydrogen generated to react with the fiber-coated TiO ₂ may be insufficient within the process time. In addition, if the molar ratio of hydrochloric acid (HCl) to 1 mole of sodium borohydride (NaBH ₄ ) is lower than 0.8, the absolute amount of hydrogen generated in the reaction with NaBH ₄ may decrease or a problem of delaying the hydrogen generation reaction may occur.If it is higher than 2, hydrogen There may be a problem that the reaction to occur is too rapid.

8 is an image showing an air cleaning filter according to a manufacturing example of the present invention.

Here, FIG. 8 (a) shows the air cleaning filter fabric manufactured by Preparation Example 2, and FIG. 8 (b) shows the air cleaning filter fabric manufactured by Preparation Example 3.

Manufacturing Example 4 (Implementation of the light source in the air cleaning filter)

The air cleaning filter fabric is folded at regular intervals and placed in a cylindrical structure to implement a cylindrical air cleaning filter with open upper and lower parts, and a high-power LED module with a peak emission wavelength of 405 nm arranged with a lens in the center of the lower part of the air cleaning filter is placed. Here, the lens performs a function of irradiating light only on the inner wall of the cylindrical air cleaning filter in the LED package attached to the heat sink.

Comparative example

The fabric coated with a commercial TiO ₂ photocatalyst (Aeroxide P25) was used in Comparative Example 1 and the photocatalyst-coated fabric prepared according to Preparation Example 2 of the present invention was treated by chemical reduction of the photocatalytic material of Comparative Example 2 and Preparation Example 3 of the present invention. A photocatalytic decomposition experiment was performed using the prepared visible light-excitation enhanced photocatalytic coated fabric as Comparative Example 3. Experimental conditions were placed in a certain amount of methylene blue (MB) solution of Comparative Examples 1, 2, and 3 of the same size, respectively, and irradiated to Comparative Examples 1, 2, and 3 for 24 hours using an LED light source irradiating visible light in the 405 nm band. .

9 is an image showing an experiment result according to a comparative example of the present invention.

9(a) shows the results for Comparative Example 1, 9(b) shows Comparative Example 2, and FIG. 9(c) shows Comparative Example 3. Here, the methylene blue solution increases in transparency as the photocatalytic decomposition increases by the LED light source.

As shown in the results shown in Fig. 9, it can be seen that more photocatalytic decomposition occurs in Comparative Example 2, which is a photocatalyst coated fabric manufactured by Preparation Example 2 of the present invention, than in Comparative Example 1, which is a fabric coated with a commercial TiO ₂ photocatalyst. In addition, it can be seen that more photocatalytic decomposition occurs in Comparative Example 3, which is a visible light-excited photocatalytic coated fabric manufactured by chemical reduction treatment of the photocatalytic material of Preparation Example 3 of the present invention than Comparative Example 2.

As described above, the air cleaning filter according to the present invention sterilizes harmful gas decomposition and harmful bacteria by harmful air introduced into the body 100 by coating a photocatalytic material on the inside and outside of the body 100 formed of a double layer, respectively. , It can effectively remove fine dust.

In addition, by coating a photocatalyst capable of excitation with visible light on the inside and outside of the main body 100, and irradiating the formed photocatalyst with visible light, stability can be secured compared to the conventional ozone method or ultraviolet method, which is controversial to human health Or, compared to the high-temperature heat treatment method, there is an advantage of reducing initial investment and maintenance cost.

In addition, it is possible to improve the excitation performance by visible light by performing a chemical reduction treatment on the body 100 coated with the photocatalytic material.

Furthermore, by forming the lens 220 of the light source unit 200 in a hemispherical shape, light emitted by the light source 210 may be uniformly irradiated to the inner wall of the main body 100.

On the other hand, the embodiments of the present invention disclosed in the specification and drawings are only presented specific examples to aid understanding, and are not intended to limit the scope of the present invention. In addition to the embodiments disclosed herein, it is apparent to those of ordinary skill in the art that other modified examples based on the technical idea of the present invention may be implemented.

100: main body 110: first filter unit
120: second filter unit 200: light source unit
210: light source 220: lens
221: first groove 222: second groove
230: heat sink

Claims (26)

A main body in the form of a column whose inside is empty so that external air is introduced;
A light source unit disposed inside the body and irradiating light into the body;
A first filter formed on an outer surface of the main body and reacted or activated by light incident by the light source to remove fine dust; And
And a second filter formed on the inner surface of the body so as to be in contact with the first filter unit and reacted or activated by light incident by the light source unit to decompose harmful gases and sterilize harmful bacteria,
The light source unit,
A light source that emits light; A lens formed in a hemispherical shape by irradiating the light emitted from the light source to the outer surface of the main body through the inner side of the main body and the inner side of the main body; And a heat sink supporting the light source and the lens and radiating heat generated from the light source,
The lens,
A first groove formed in a hemispherical shape in a lower center of the lens and in which the light source is disposed; And a second groove formed in a hemispherical shape in an upper center of the lens. An air cleaning filter using a visible light-excited photocatalyst. The method of claim 1,
The main body is an air cleaning filter using a visible light-excited photocatalyst having a cylindrical shape with an empty inside. The method of claim 1,
An air cleaning filter using a visible light-excited photocatalyst, wherein the first filter unit and the second filter unit are formed of any one of a HEPA filter, a carbon filter, and a prefilter. The method of claim 1,
The air cleaning filter using a visible light-excited photocatalyst, wherein the first filter unit and the second filter unit are formed in a double-layer structure having different fiber diameters. The method of claim 1,
The first filter unit is formed of polyethylene terephthalate (PET) having a fiber diameter of 30 μm to 50 μm,
The second filter unit is an air cleaning filter using a visible light-excited photocatalyst formed of polypropylene (PP) having a fiber diameter of 3 μm to 5 μm. delete delete delete delete The method of claim 1,
The light source unit is disposed inside the body so that the lens faces the inside of the body, and the lower surface of the heat sink is disposed to be the same surface as one side of the body. An air cleaning filter using a visible light-excited photocatalyst. The method of claim 1,
An air cleaning filter using a visible light-excited photocatalyst, wherein the light emitted from the light source unit is visible light. The method of claim 11,
The visible light is an air cleaning filter using a visible light-excited photocatalyst having a wavelength range of 400nm to 410nm having a sterilizing effect. The method of claim 1,
An air cleaning filter using a visible light-excited photocatalyst further comprising a photocatalyst material coated on a surface of each of the first filter unit and the second filter unit. The method of claim 13,
The photocatalytic material is TiO ₂ , ZnO, SnO ₂ , WO ₃ , ZnS, NiO and Fe ₂ O ₃ Air cleaning filter using a visible light-excited photocatalyst comprising any one of the material. The method of claim 13,
The photocatalyst material is an air cleaning filter using a visible light-excited photocatalyst, which is formed of a material doped with metal ions in chalcogenide. The method of claim 13,
The photocatalytic material is TiO ₂ Formed of a material, and the TiO ₂ is TiO ₂ Air using visible light-excited photocatalyst is formed through band gap control by doping transition metals of V, Cr, Mn, Fe, Co, Ni, Cu, Zn or non-metal ions of B, C, N, and F inside Clean filter. The method of claim 15,
The chalcogenide includes any one of CuInGaSe ₂ , Cu ₂ ZnSnS ₄ material,
The metal ion is an air cleaning filter using a visible light-excited photocatalyst containing any one of Ag, Pt, and Au materials. The method of claim 1,
An air cleaning filter using a visible light-excited photocatalyst disposed under the main body and further comprising a fan for introducing external air into the main body. Preparing a liquid photocatalytic material;
Coating the liquid photocatalytic material on a filter fabric formed as a double layer;
Chemical reduction treatment of the filter fabric coated with the liquid photocatalytic material using a chemical reduction method; And
Folding the reduced-treated filter fabric at regular intervals to form a cylindrical structure, and including the step of arranging a light source in the cylindrical filter fabric,
The light source unit,
A light source that emits light; A lens formed in a hemispherical shape by irradiating the light emitted from the light source with the filter fabric formed of the double layer; And a heat sink supporting the light source and the lens and radiating heat generated from the light source,
The lens,
A first groove formed in a hemispherical shape in a lower center of the lens and in which the light source is disposed; And a second groove formed in a hemispherical shape in an upper center of the lens. A method of manufacturing an air cleaning filter using a visible light-excited photocatalyst. The method of claim 19, wherein the preparing of the liquid photocatalytic material comprises:
Mixing titanium tetraisopropoxide (TTIP) and a solvent;
Mixing the mixture with ultrapure water (DI) to form a sol-gel solution;
A method of manufacturing an air cleaning filter using a visible light-excited photocatalyst comprising the step of forming a liquid photocatalyst material using the sol-gel solution using a hydrothermal synthesis process. The method of claim 20,
The solvent is a method of manufacturing an air cleaning filter using a visible light-excited photocatalyst comprising isopropyl alcohol (IPA) and glacial acetic acid (AA). The method of claim 21,
The blending molar ratio to 1 mole of the titanium tetraisopropoxide (TTIP) for forming the liquid photocatalytic material is, TTIP: IPA: AA: DI = 1: 1 to 5: 3 to 12: 100. A method of manufacturing an air cleaning filter using a type photocatalyst. The method of claim 19, wherein the double layer,
A first filter formed on the outside of the filter fabric and formed of polyethylene terephthalate (PET) having a fiber diameter of 30 μ to 50 μm; And
A method of manufacturing an air cleaning filter using a visible light-excited photocatalyst comprising a second filter formed on the inside of the filter fabric and made of polypropylene (PP) having a fiber diameter of 3 μ to 5 μm. The method of claim 19, wherein the chemical reduction treatment step,
Dissolving hydrochloric acid in ultrapure water to form a reducing solution;
Mixing the reducing solution with sodium borohydride (NaBH ₄ ); And
A method of manufacturing an air cleaning filter using a visible light-excited photocatalyst comprising the step of immersing the filter fabric coated with the photocatalytic material in the mixture. The method of claim 24,
The sodium borohydride (NaBH ₄ ) 1 mole ratio for the chemical reduction treatment was mixed with a molar ratio of NaBH ₄ : H ₂ O: HCl = 1: 3 to 10: 0.8 to 2 using a visible light-excited photocatalyst Method of manufacturing an air cleaning filter. delete

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