KR20200073661A - Air Cleaning Filter Using Visible Light Excitation Photocatalyst and Manufacturing Method Thereof - Google Patents

Abstract

Disclosed is an air cleaning filter using a visible light excitation type photocatalyst having a double-layer structure capable of sterilizing harmful gases and sterilizing harmful bacteria and removing fine dust. This can sterilize harmful gas decomposition and harmful bacteria by harmful air flowing into the main body by forming photocatalytic materials on the inside and outside of the main body formed of a double layer, and effectively remove fine dust. In addition, by forming a photocatalyst capable of being excited by visible light inside and outside the body, and irradiating visible light to the formed photocatalyst material, stability can be secured compared to the ozone method or ultraviolet method, which has been controversial to the human body, and conventional plasma or high temperature heat treatment Compared to the method, the 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 excitation type photocatalyst and a manufacturing method thereof, and more specifically, air using a visible light excitation type photocatalyst capable of dissolving harmful gases and sterilizing harmful bacteria and removing fine dust. It relates to a clean filter.

Recently, as environmental pollution has increased, the harmfulness of the human body due to air pollution is 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 work for a long time. Particularly, it is known that ultra-fine particulate matter of PM 2.5M or less, which is mainly generated from automobile exhaust gas, penetrates deep into the respiratory system of the human body and attaches to lung tissue, causing respiratory disease, and is absorbed into blood vessels, causing stroke or heart disease.

Air cleaners are often used to purify such contaminated air with clean air, and air cleaners inhale polluted air with a blower to collect fine dust or bacteria by a dust removal device, that is, filter means, or to remove dust. It performs odor, harmful gas and deodorization functions.

The air cleaning method includes 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 are controversial, and the method using plasma or the high temperature heat treatment method has a disadvantage of high initial investment and maintenance cost.

Korean Registered Patent 10-0750993

The technical problem to be achieved by the present invention is to irradiate visible light on a photocatalytic layer formed of a double layer to sterilize harmful gases and sterilize harmful bacteria, and to clean air using a visible light excitation type photocatalyst capable of removing fine dust and a method for manufacturing the same. To provide.

The air cleaning filter using the visible light excitation-type photocatalyst of the present invention for solving the above problems is a body having an empty interior so that outside air is introduced, a light source unit that irradiates light inside the body, and is formed outside the body, and the light source unit Reactive or activated by the light incident by the first filter unit to remove fine dust, formed inside the body so as to contact the first filter unit, reacted or activated by the light incident by the light source unit, harmful It includes a second filter unit to decompose gas and sterilize harmful bacteria.

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

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

The body may be formed of a double layer structure having different diameters of fibers.

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

The light source unit may include a light source that emits light, a lens that irradiates light emitted from the light source into the body, and a heat sink that supports the light source and the lens and dissipates heat generated by the light source.

The lens may have a hemisphere shape.

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

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

The light source unit may be disposed inside the main body such that the lens faces the inside of the main body, and may be disposed such that a lower surface of the heat sink is flush with one side surface of the main body.

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

The visible light may have a wavelength range of 400nm to 410nm having a bactericidal action.

Each of the first filter part and the second filter part may further include a photocatalytic material coated on the 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 metal ions on chalcogenide.

The photocatalytic material is TiO ₂ It is formed of a material, the TiO ₂ is TiO ₂ V, Cr, Mn, Fe, Co, Ni, Cu, and Zn may be formed through band gap control by doping transition metals or non-metal ions of B, C, N, and F.

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

It may be disposed on the lower portion of the main body, and may further include a fan that introduces external air into the main body.

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

The step of preparing 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, and hydrothermal-synthesizing 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 compounding molar ratio of 1 mole of titanium tetraisopropoxide (TTIP) for forming the liquid photocatalytic material may be formed of 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 portion formed of polyethylene terephthalate (PET) having a fiber diameter of 30 μ to 50 μ, and formed inside the filter fabric, of the fiber A second filter part formed of polypropylene (PP) having a diameter of 3 μ to 5 μ may be included.

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 filtering the filter fabric coated with the photocatalytic material on the mixture. And immersing.

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

The light source unit may include a light source for emitting light, a light radiating from the light source into the main body, a lens formed in a hemispherical shape, a support for the light source and the lens, and a heat sink for radiating heat generated by the light source It can contain.

According to the present invention, by forming photocatalytic materials on the inside and outside of the body formed of a double layer, respectively, it is possible to effectively 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 being excited by visible light inside and outside the main body, and irradiating visible light on the formed photocatalyst material, stability can be secured compared to the ozone method or ultraviolet ray method, which has been controversial to the human body.

In addition, it is possible to reduce the initial investment and maintenance cost compared to the conventional plasma or high temperature heat treatment method because it can sterilize harmful gas decomposition and harmful bacteria and effectively remove fine dust by using visible light within and around 405 nm that has a sterilizing effect. There is an advantage.

In addition, the excitation performance by visible light may be improved by performing a chemical reduction treatment on the body coated with the photocatalytic material.

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

The technical effects of the present invention are not limited to those mentioned above, and other technical effects 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 excitation type photocatalyst of the present invention.
2 is an image showing the double-layer structure of the 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 a light traveling direction according to the lens of the present invention.
5 is a graph showing the results of light measurement 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 excitation type photocatalyst of the present invention.
7 is an image showing before and after the 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 production example of the present invention.
9 is an image showing the experimental results according to a comparative example of the present invention.

The present invention can be applied to a variety of transformations and may have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all conversions, equivalents, and substitutes included in the spirit and scope of the present invention. In the description of the present invention, when it is determined that detailed descriptions of related well-known technologies may obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

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

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

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

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

The main body 100 is formed of any one of a HEPA filter, a carbon filter, and a pre-filter, and may be formed in a double layer structure. In more detail, the main body 100 may be formed of a cylindrical HEPA filter, and the cylindrical shape may be formed of 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 diameters of different sizes, respectively.

Here, the outer side of the main body 100 is formed by a first filter unit 110 that reacts or is 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 inside the main body 100 so as to come into contact with the first filter unit 110, and is reacted or activated by the 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 of a double layer.

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

Here, Figure 2 (a) is an image showing the first filter unit 110 formed on the outside of the body 100, Figure 2 (b) is a second filter unit 120 formed inside the 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 (polypropylene, 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, the outside air flowing into the main body 100 from the outside passes through the first filter portion 110 formed of PET on the outside of the double-layer structure and passes through the second filter portion 120 formed of PP on the inside, so that the body 100 ) It can be introduced 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 a photocatalytic material coated on the first filter unit 110 and the second filter unit 120, respectively, so that the photocatalytic material can be reacted or activated.

Therefore, the first filter portion 110 formed on the outside of the double layer structure can function as a filtration layer to remove fine dust, and the second filter portion 120 formed on the inside has a function of dissolving harmful gases and sterilizing harmful bacteria. Can function as a layer.

That is, the air cleaning filter according to the present invention has an effect capable of simultaneously removing not only fine dust but also harmful gases and harmful bacteria by 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 light emitted from the light source unit 200 into the main body 100. That is, the light source unit 200 provides light necessary 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 gas and sterilizing harmful bacteria. To be done.

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

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

1, 3 and 4, the light source unit 200 according to the present invention is a light source 210 for emitting light, a lens 220 arranged to uniformly irradiate the emitted light inside the body 100 And it may include a heat sink 230 for dissipating heat generated by the light source 210.

The light source 210 is formed of a light source 210 such as a 254nm sterilization lamp, UV-A UV lamp, UV-C, -A band LED that emits light, for example, and may include visible light having a sterilizing effect. have. In more detail, the visible light of the present invention may be visible light having a wavelength range of 400 nm to 410 nm, and preferably 405 nm so as to activate the photocatalytic material coated on the main 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 ozone method, photocatalytic method using ultraviolet rays, plasma method, and high temperature heat treatment method have been used. The method is controversial about the harmfulness of 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.

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

The lens 220 of the light source unit 200 may be arranged to house the light source 210. That is, the light source 210 may be surrounded by the lens 220 so that 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 that dissipates heat generated by the light source 210, and the lens 220 has the light source 210 disposed under the center of the lens 220. It can be disposed on the heat sink 230 as possible.

1, the light source unit 200 may be disposed inside the main body 100 having a cylindrical shape. That is, the light source unit 200 is disposed inside the body 100 such 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 surface as the lower one surface. Therefore, light irradiated from the light source unit 200 may be irradiated only in the inner direction of the cylinder.

At this time, 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 surface 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 in the direction of 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 larger size of the second groove 222 than the size of the first groove 221.

The first groove 221 may provide a space in which the light source 210 is disposed such 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 in the outer wall direction.

The second groove 222 may function such that light irradiated from the light source 210 in the longitudinal direction of the body 100 through the lens 220 is refracted in the direction of the inner wall of the body 100. That is, as illustrated in FIG. 4, light irradiated in a direction other than the center of the hemisphere shape is irradiated in the direction of the inner wall of the main body 100, and irradiated in the center direction of the hemisphere shape and irradiated in the outer direction of the body 100 The light is refracted by the second groove 222 to change the direction of light in the direction of the inner wall of the body 100. Therefore, the lens 220 according to the present invention can be focused to the inner wall of the cylindrical body 100 by the second groove 222 formed in the hemispherical shape and the upper center of the hemispherical shape.

5 is a graph showing the results of light measurement according to the lens of the present invention.

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

In addition, a fan 300 that applies negative pressure so that external air flows into the main body 100 may be further included at the top or bottom of the main body 100. Therefore, the external air containing harmful gas or harmful bacteria may be introduced into the main body 100 by the fan 300, and the external air introduced may be irradiated from the light source unit 200 to the main body 100. ) Can be decomposed or sterilized by reacting or activating the photocatalytic material coated on the.

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

As an embodiment, the 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 in a double layer structure of the body 100 formed of a cylinder Each photocatalyst material may be coated on the surface. When 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 specific surface area of the reaction.

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 emitted from the light source unit 200. More specifically, it may be formed of a material that reacts or activates visible light in a 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 visible light in a band of 405 nm. It can be formed of a material.

For example, when a visible light in the 405nm band is irradiated to a living bacterium, it stimulates a porphyrin molecule present in the bacterium to inactivate the cell, and eventually to generate Reactive Oxygen Species (ROS) that can be destroyed. do. The free radicals thus generated may be processed by irradiating visible light in the 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 is activated to visible light in 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 capable of excitation in visible light in a 405 nm band It may contain any one of the substances. The photocatalytic material is coated on the entire inner and outer walls of the main body 100 as a photocatalyst, thereby generating electron-holes on a metal surface by light irradiated from the light source unit 200, and they react with hydroxyl groups (H ₂ O) in the air. To produce hydroxide radicals (OH). These hydroxide radicals (OH) are very powerful oxidizing agents and can be responsible for sterilization and decomposition of various types 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 . TiO ₂ The material is TiO ₂ V, Cr, Mn, Fe, Co, Ni, Cu, and Zn may be formed through band gap control by doping transition metals or non-metal ions of B, C, N, and F.

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

As an example, TiO ₂ prepared as described above as a photocatalytic material is coated on the first filter unit 110 and the second filter unit 120, and the TiO ₂ photocatalyst layer is hydrogenated using a chemical reducing agent to form TiO _{2 - x} By forming the H _x photocatalyst layer, the absorbance in the visible light band can be improved. Here, sodium borohydride (NaBH ₄ ) may be used as the chemical reducing agent used for the chemical reduction method.

As another embodiment, the photocatalytic material formed on the first filter unit 110 and the second filter unit 120 may be formed of a material doped with metal ions on chalcogenide. Here, the chalcogenide material is CuInGaSe ₂ (CIGS), Cu ₂ ZnSnS ₄ (CZTS) Any one of the materials may be included, and the metal ion may include any one of Ag, Pt, and Au materials. Preferably CuInGaSe ₂ (CIGS), Cu ₂ ZnSnS ₄ (CZTS) It may 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 of transition metals or non-metal ions may be responsible for sterilization and decomposition of various types of organic compounds, but this promotes electron-hole recombination. When the recombination of these electron-holes is promoted, the photocatalytic efficiency is lowered. Therefore, in order to prevent the disadvantage that the photocatalytic efficiency is lowered by the recombination of the electron-holes, recombination of the electron-holes can be suppressed by doping the noble metal ions as described above.

The photocatalytic 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 an antiseptic effect as compared to the ozone method and has a sterilizing effect compared to the conventional ultraviolet method and ozone method. It is more preferable to use visible light in the 405 nm band that can secure stability. Therefore, the first filter unit 110 and the second filter unit 120 according to the present invention are reacted or activated by visible light in the 405 nm band emitted from the light source unit 200 to finely flow into the 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 excitation type photocatalyst of the present invention.

Referring to FIG. 6, a method for manufacturing an air cleaning filter using a visible light excitation type photocatalyst according to the present invention comprises the steps of preparing a liquid photocatalytic material (S310) and coating the liquid photocatalytic material on a filter fabric formed of a double layer (S320) ), the step of chemically reducing the filter fabric coated with the liquid photocatalytic material using a chemical reduction method (S330) and folding the reduced-treated filter fabric at regular intervals to form a cylindrical structure, and a light source unit in the filter fabric of the cylindrical structure. And a step of placing (S340).

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

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

In the first step, 11.5 mL of titanium tetra isopropoxide (TTIP) and 20 mL of glacial acetic acid (AA) are sequentially added to 3 mL of isopropyl alcohol (IPA) and mixed. When mixing is complete, a second step is added to the 70 mL ultrapure water (DI) dropwise to form a sol-gel solution. In the third step, the formed sol-gel solution is placed in a 100 mL Teflon material container, a container containing the sol-gel solution is placed in a stainless steel hydrothermal synthesizer, and then raised to 150° C. at a temperature of 3° C./min at 150° C. and 150° C. to 1.5° C. Keep time. Thereafter, a hydrothermal synthesis process of natural cooling to room temperature is performed to prepare a liquid photocatalytic material.

Here, the reaction scheme for the production of a liquid photocatalytic material can be represented by the following <Scheme 1> and <Scheme 2>.

<Scheme 1>

<Reaction Scheme 2>

In addition, when preparing the liquid photocatalytic material, the proper mixing ratio (mol.) is titanium tetra isopropoxide (TTIP): isopropyl alcohol (IPA): glacial acetic acid (AA): ultrapure water (DI) = 1: 1 to 5: 3 ~12: It is preferable to form to be 100. This is because, when the molar ratio of isopropyl alcohol (TTA) to 1 mole of isopropoxide (TTIP) is lower than 1, the coating solution concentration is low. Because it is not done. In addition, if the molar ratio of glacial acetic acid (AA) compared to 1 mole of isopropoxide (TTIP) is less than 3, the pH of the coating solution is high, and when coating the surface of the fiber, the coating thickness may be unevenly coated, resulting in a problem of peeling off. , If it is higher than 12, the pH of the coating solution is too low, which may cause a problem that the coating amount is insufficient below the uniform coating level.

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

A HEPA filter fabric is formed in which a polypropylene (PP) fiber having a diameter of about 4 μm is spun inside and a polyethylene terephthalate (PET) fiber having a diameter of about 40 μm is spun into a double layer. The prepared filter fabric is washed with ultrapure water (DI) and a cleaning agent, dried naturally, immersed in a liquid photocatalytic material for 10 minutes, and then dried at room temperature. When the drying is completed, vacuum drying at 70° C. for 3 hours is performed, followed by DI cleaning and vacuum drying to complete coating of the air cleaning filter using a liquid photocatalytic material.

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

Preparation Example 3 (Chemical reduction method of photocatalytic material)

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

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

<Scheme 3>

<Reaction Scheme 4>

<Reaction Scheme 5>

In addition, it is preferable to form sodium borohydride (NaBH4): ultrapure water (H2O): hydrochloric acid (HCl) = 1: 3 to 10: 0.8 to 2 as an appropriate compounding ratio (mol.) when preparing the chemical reducing solution. . This means that if the molar ratio of ultra-pure water (H ₂ O) to 1 mol of sodium borohydride (NaBH ₄ ) is lower than 3, the solution amount of the reducing agent to be immersed is insufficient to not immerse, and the relative amount of HCl is excessive, resulting in NaBH ₄ Since the reaction with (NaBH ₄ (s) + HCl (aq) + 3H ₂ O(aq) → NaCl(aq) + H ₃ BO ₃ (aq) + 4H ₂ (g)) is faster, H ₂ is rapidly generated 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, which may cause a problem that the amount of hydrogen to be reacted with the fiber-coated TiO ₂ may be insufficient within a process time. In addition, when the molar ratio of hydrochloric acid (HCl) to 1 mol of sodium borohydride (NaBH ₄ ) is lower than 0.8, an absolute amount of hydrogen generation may decrease in a reaction with NaBH ₄ or a hydrogen generation reaction delay problem may occur. The problem that the occurrence reaction becomes too fast may occur.

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

Here, FIG. 8(a) shows the air cleaning filter fabric manufactured by Production Example 2, and FIG. 8(b) shows the air cleaning filter fabric manufactured by Production 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 realize a cylindrical air cleaning filter with upper and lower openings, and a peak emission wavelength 405nm high power LED module disposed with a lens is arranged in the center of the lower part of the air cleaning filter. Here, the lens performs a function of irradiating light only to the inner wall surface of the cylindrical air cleaning filter in the LED package attached to the heat sink.

Comparative example

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

9 is an image showing experimental results according to a comparative example of the present invention.

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

As shown in the results shown in Figure 9, it can be seen that more photocatalytic decomposition occurs in Comparative Example 2, the photocatalyst-coated fabric prepared by Preparation Example 2 of the present invention, than Comparative Example 1, which is a commercially available TiO ₂ photocatalyst coated fabric. It can be seen that more photocatalytic decomposition occurs in Comparative Example 3, which is a visible light excitation-enhanced photocatalytic coating fabric prepared by the chemical reduction method 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 caused by harmful air flowing into the main body 100 by coating a photocatalytic material on the inside and outside of the main body 100 formed of a double layer, respectively. , It can effectively remove fine dust.

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

In addition, excitation performance by visible light may be improved 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 can be uniformly irradiated to the inner wall surface of the body 100.

On the other hand, the embodiments of the present invention disclosed in the specification and drawings are merely presented as specific examples for ease of understanding, and are not intended to limit the scope of the present invention. It is apparent to those skilled in the art to which the present invention pertains that other modified examples based on the technical idea of the present invention can be implemented in addition to the embodiments disclosed herein.

100: body 110: the 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 body having an empty interior so that external air is introduced;
A light source unit that irradiates light inside the body;
A first filter unit formed outside the main body and reacting or activating by light incident on the light source unit to remove fine dust; And
A visible light excitation type photocatalyst that is formed inside the body so as to come into contact with the first filter unit, and includes a second filter unit that reacts or is activated by light incident on the light source unit to decompose harmful gases and sterilize harmful bacteria. Air cleaning filter used. According to claim 1,
The main body is an air cleaning filter using a visible light excitation type photocatalyst that has a hollow cylindrical shape. According to claim 1,
The main body is an air purifying filter using a visible light excitation type photocatalyst formed of any one of a HEPA filter, a carbon filter, and a pre-filter. According to claim 1,
The main body is an air cleaning filter using a visible light excitation type photocatalyst that is formed of a double layer structure having different diameters of fibers. According to claim 1,
The first filter portion is formed of polyethylene terephthalate (PET) having a fiber diameter of 30 μm to 50 μm,
The second filter part is an air cleaning filter using a visible light excitation type photocatalyst that is formed of polypropylene (PP) having a fiber diameter of 3 μm to 5 μm. According to claim 1, The light source unit,
A light source that emits light;
A lens that irradiates light emitted from the light source into the main body; And
An air cleaning filter using a visible light excitation type photocatalyst including a heat sink that supports the light source and the lens and dissipates heat generated by the light source. The method of claim 6,
The lens is an air cleaning filter using a visible light excitation type photocatalyst having a hemisphere shape. The method of claim 6, wherein the lens,
A first groove formed in the lower center of the lens; And
Air cleaning filter using a visible light excitation type photocatalyst including a second groove formed in the upper center of the lens. The method of claim 8,
The first groove and the second groove are air cleaning filters using a visible light excitation type photocatalyst that is formed in a hemisphere shape. The method of claim 6,
The light source unit is an air cleaning filter using a visible light excitation type photocatalyst, wherein the lens is disposed inside the main body so that the lens faces the inside of the main body, and the lower surface of the heat sink is arranged to be the same surface as one side of the main body. According to claim 1,
The light emitted from the light source unit is visible light, an air cleaning filter using a visible light excitation type photocatalyst. The method of claim 11,
The visible light is an air cleaning filter using a visible light excitation type photocatalyst having a wavelength range of 400nm to 410nm having a sterilizing action. According to claim 1,
The first filter part and the second filter part are air-cleaning filters using a visible light excitation type photocatalyst each further comprising a photocatalyst material coated on a surface. 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 excitation type photocatalyst comprising any one of the materials. The method of claim 13,
The photocatalyst material is an air cleaning filter using a visible light excitation type photocatalyst that is formed of a material doped with metal ions on a chalcogenide. The method of claim 13,
The photocatalytic material is TiO ₂ It is formed of a material, the TiO ₂ is TiO ₂ V, Cr, Mn, Fe, Co, Ni, Cu, Zn doped with a transition metal or B, C, N, or F, a non-metal ion is formed through bandgap control and is formed by bandgap control. Clean filter. The method of claim 15,
The chalcogenide includes any one of CuInGaSe ₂ and Cu ₂ ZnSnS ₄ materials,
The metal ion is an air cleaning filter using a visible light excitation type photocatalyst containing any one of Ag, Pt, and Au materials. According to claim 1,
An air cleaning filter using a visible light excitation type photocatalyst disposed on the lower portion of 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 of a double layer;
Chemically reducing the filter fabric coated with the liquid photocatalytic material using a chemical reduction method; And
A method of manufacturing an air cleaning filter using a visible light excitation type photocatalyst, wherein the reduction-treated filter fabric is folded at regular intervals to form a cylindrical structure, and a light source is disposed in the filter fabric of the cylindrical structure. The method of claim 19, wherein the step of preparing the liquid photocatalytic material,
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 excitation type photocatalyst comprising the step of forming a liquid photocatalytic material using the sol-gel solution using a hydrothermal synthesis process. The method of claim 20,
The solvent is isopropyl alcohol (IPA) and glacial acetic acid (AA) containing a visible light excitation type photocatalyst method of manufacturing an air cleaning filter using a photocatalyst. The method of claim 21,
The molar ratio of the titanium tetraisopropoxide (TTIP) to 1 mole to form the liquid photocatalytic material is TTIP: IPA: AA: DI = 1: 1-5: 3-12: 100 visible light excitation Method for manufacturing air cleaning filter using fluorescent photocatalyst. The bilayer of claim 19,
A first filter unit formed on the outer side of the filter fabric and formed of polyethylene terephthalate (PET) having a fiber diameter of 30 μ to 50 μ; And
A method of manufacturing an air cleaning filter using a visible light excitation type photocatalyst formed on the inside of the filter fabric and including a second filter portion formed of polypropylene (PP) having a fiber diameter of 3 μ to 5 μ. 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 excitation type photocatalyst comprising immersing the filter fabric coated with the photocatalytic material in the mixture. The method of claim 24,
The molar ratio of sodium borohydride (NaBH ₄ ) to 1 mole for the chemical reduction treatment is NaBH ₄ : H ₂ O: HCl = 1: 3 to 10: 0.8 to 2 using a visible light excitation type photocatalyst. Method for manufacturing air cleaning filter. The method of claim 19, wherein the light source unit,
A light source that emits light;
A lens irradiated with light emitted from the light source into the main body and formed in a hemisphere shape; And
A method of manufacturing an air cleaning filter using a visible light excitation type photocatalyst comprising a heat sink that supports the light source and the lens and radiates heat generated from the light source.

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