CN109310937B

CN109310937B - Photocatalyst functional filter

Info

Publication number: CN109310937B
Application number: CN201780036766.7A
Authority: CN
Inventors: 金荷娜; 李东一; 金孝重; 李晔
Original assignee: LG Hausys Ltd
Current assignee: LX Hausys Ltd
Priority date: 2016-06-13
Filing date: 2017-06-08
Publication date: 2021-11-23
Anticipated expiration: 2037-06-08
Also published as: CN109310937A; WO2017217693A1; JP6726313B2; KR101930709B1; JP2019520203A; KR20170140845A

Abstract

The present invention provides a photocatalyst functional filter, which comprises a photocatalyst layer, an adsorbent layer and a base material layer in sequence, wherein the photocatalyst layer comprises: a first inorganic binder having hydrophilicity; and a photocatalyst, the adsorbent layer including: a second inorganic binder different from the first binder; and an adsorbent.

Description

Photocatalyst functional filter

Technical Field

The present invention relates to photocatalyst functional filters.

Background

A general filter used for a medical mask, an automobile seat, and the like has a function of capturing and filtering bacteria or gaseous substances. However, such a general filter does not have a self-degradation function of bacteria or gaseous substances. On the other hand, in the case where the filter is coated with only the photocatalyst, the self-degradation function is exhibited, but since it takes time to adsorb harmful substances diffused in the air to the surface of the photocatalyst, the effect is hardly seen in a short time, and in the case where the filter is coated with only the adsorbent, bacteria or gaseous substances can be removed in a short time, but the effect cannot be seen after the adsorbent is saturated.

Therefore, there is a need for research into a method of improving filtration efficiency in a manner of using both a photocatalyst and an adsorbent.

Disclosure of Invention

The inventionTechnical problem to be solved

An embodiment of the present invention provides a photocatalyst functional filter that can adsorb harmful substances in the air in a short time and rapidly degrade the adsorbed harmful substances.

Technical scheme

An embodiment of the present invention provides a photocatalyst functional filter including, in order, a photocatalyst layer, an adsorbent layer, and a base material layer, the photocatalyst layer including: a first inorganic binder having hydrophilicity; and a photocatalyst, the adsorbent layer including: a second inorganic binder different from the first binder; and an adsorbent.

The first inorganic binder may include a material selected from titanium dioxide (TiO)₂) Binder, colloidal silica (colloidal silica), and silicon dioxide (SiO)₂) A binder, an alumina sol, a zirconia sol, and combinations thereof.

The contact angle between the first inorganic binder and water may be 0 ° to 20 °.

The photocatalyst may include a metal oxide and metal particles.

The above metal oxide may include one selected from the group consisting of titanium oxide, tungsten oxide, zinc oxide, niobium oxide, and combinations thereof.

The metal particles may include one selected from the group consisting of tungsten, chromium, vanadium, molybdenum, copper, iron, cobalt, manganese, nickel, platinum, gold, silver, cerium, cadmium, zinc, magnesium, calcium, strontium, barium, and combinations thereof.

The particle diameter (particle diameter) of the photocatalyst may be 20nm to 100 nm.

The photocatalyst layer may contain 50 to 100 parts by weight of the first inorganic binder based on 100 parts by weight of the photocatalyst.

The thickness of the photocatalyst layer may be 0.2 μm to 1 μm.

The second inorganic binder may include one selected from the group consisting of tetraethyl orthosilicate (TEOS), methyltrimethoxysilane (methyl) silane, methyltriethoxysilane (methyl) silane, and a combination thereof.

The adsorbent may include one selected from the group consisting of activated carbon, zeolite, apatite, alumina, silica, and combinations thereof.

The particle size of the above adsorbent may be 0.02 μm to 1 μm.

The adsorbent layer may contain 50 to 100 parts by weight of the second inorganic binder based on 100 parts by weight of the adsorbent.

The thickness of the adsorbent layer may be 0.2 μm to 1 μm.

The substrate layer may include one selected from the group consisting of a non-woven fabric, a polymer film, a glass substrate, and a combination thereof.

Advantageous effects

The photocatalyst functional filter can easily trap harmful substances in the air in a short time through the adsorbent, can prevent the substrate layer from being polluted through the deodorization, antibacterial and antiviral functions of the photocatalyst, and can degrade the gaseous substances into substances harmless to the human body through the photoreaction even under the condition that the gaseous substances are hung.

The invention has the advantages that the photocatalyst can be intensively dispersed on the surface of the photocatalyst functional filter, thereby improving the degradation efficiency of harmful substances in the air.

Drawings

Fig. 1 schematically shows a cross section of an organic fiber of a photocatalyst-functional nonwoven fabric according to an example of the present invention.

Fig. 2 schematically shows a photocatalyst according to an example of the present invention.

Detailed Description

The advantages and features of the present invention and methods of accomplishing the same will become more apparent with reference to the following examples. However, the present invention can be implemented in various different embodiments, and is not limited to the embodiments disclosed below, which are provided only for the purpose of making the disclosure of the present invention complete and informing a person of ordinary skill in the art of the scope of the present invention, which is defined only by the scope of the claims of the present invention. Like reference numerals refer to like elements throughout the specification.

In the drawings, the thickness is exaggerated for the sake of clarity of the layers and regions. Also, in the drawings, the thickness of a part of layers and regions is exaggeratedly shown for convenience of explanation.

Further, in the present specification, when a layer, a film, a region, a plate, or the like is referred to as being "on" or "on" another portion, it includes not only a case where "directly" on "the other portion but also a case where another portion is present between the two. Conversely, when a portion is said to be "directly on" another portion, it means that there is no other portion in between. Further, when a portion of a layer, a film, a region, a plate, or the like is referred to as being "under" or "under" other portion, this includes not only a case where "directly" under "the other portion but also a case where the other portion is present therebetween. Conversely, when a portion is said to be "directly under" another portion, it means that there is no other portion in between.

An example of the present invention provides a photocatalyst functional filter comprising, in order: photocatalyst layer, adsorbent layer and substrate layer, above-mentioned photocatalyst layer contains: a first inorganic binder having hydrophilicity; and a photocatalyst, the adsorbent layer including: a second inorganic binder different from the first binder; and an adsorbent.

Referring to fig. 1, the photocatalyst functional filter 100 includes a photocatalyst layer 110, an adsorbent layer 120, and a base material layer 130 in this order.

The photocatalyst layer 110 includes a photocatalyst 150 and a first inorganic binder 140, and the adsorbent layer 120 includes a second inorganic binder 160 and an adsorbent 170.

In the case of the conventional filter, the photocatalyst is directly attached to the surface of the adsorbent without being separately layered. In this case, even if the same amount of photocatalyst is added, the amount of photocatalyst exposed to the filter surface is small, and the degradation efficiency of organic substances in the air is lowered.

Therefore, the present invention can improve the efficiency of degrading harmful substances in the air by locating the photocatalyst layer on the outermost surface of the photocatalyst functional filter and separating the photocatalyst layer from the adsorbent layer.

The photocatalyst filter plays a role in effectively trapping and degrading harmful substances in the air. Therefore, the photocatalyst layer needs to be able to easily react with harmful substances in the air, and the adsorbent layer needs to be able to be exposed to the maximum extent on the surface of the photocatalyst functional filter.

In one embodiment of the present invention, the photocatalyst functional filter can favorably perform the above-described functions by appropriately limiting or designing the formation, composition, and the like of the photocatalyst layer and the adsorbent layer.

The photocatalyst layer is positioned on the surface of the outermost shell of the photocatalyst functional filter, so that the degradation efficiency of harmful substances in the air can be improved.

Specifically, the thickness of the above photocatalyst layer may be about 0.2 μm to 1 μm. In the case where the thickness of the photocatalyst layer is less than the thickness range, the bonding force between the photocatalyst and the photocatalyst layer is reduced, thereby decreasing durability, and the amount of the photocatalyst required for photoreaction cannot be sufficiently secured. When the thickness of the photocatalyst layer is larger than the above range, the adsorbent is not exposed to the outside of the photocatalyst layer, so that the degree of adsorption of harmful substances in the air is reduced, the probability of occurrence of cracks (cracks) on the surface is increased, the durability of the photocatalyst layer is reduced, and the production cost may be increased.

The photocatalyst layer contains a first inorganic binder having hydrophilicity. The first inorganic binder may include one of the group consisting of a titania binder, colloidal silica, a silica binder, alumina sol, zirconia sol, and a combination thereof. The first inorganic binder may allow the photocatalyst to be well adhered to the photocatalyst functional filter, and, for example, in the case where the first inorganic binder includes a titanium dioxide binder, the first inorganic binder has excellent compatibility with the photocatalyst, and not only does not lose the catalytic function of the photocatalyst, but also allows the photocatalyst to be firmly adhered to the surface of the photocatalyst functional filter.

The contact angle between the first inorganic binder and water may be about 20 ° or less. Specifically, it may be about 0(zero) ° to about 20 °. The Contact angle with water was measured using a Contact angle measuring device (Contact angle system OCA), and the Contact angle was measured at a normal temperature and atmospheric pressure by setting a measurement volume (2 uL) to be a volume of water falling on the surface for measuring the Contact angle at 25 ℃ and 1 atm.

When the contact angle of the first inorganic binder is larger than the above range, a hydrophilic surface cannot be formed, and the photocatalytic performance is deteriorated. Specifically, if the surface of the photocatalyst is not sufficiently hydrophilic, water molecules required for the photocatalyst reaction cannot be effectively adsorbed, and the photocatalyst performance may eventually be degraded. That is, the contact angle of the first inorganic binder satisfies the above range, so that effective expression of photocatalyst performance can be easily ensured.

The first inorganic binder has hydrophilicity, so that water molecules required for realizing photocatalyst performance through a hydrophilic surface can be effectively adsorbed, and thus, the photocatalyst performance can be maximized as compared with a non-hydrophilic binder.

The photocatalyst layer contains a photocatalyst. The above-mentioned photocatalyst generally means a substance that promotes a chemical reaction when exposed to light. For example, reference is made to substances that can promote redox reactions associated with the degradation or oxidation of organic odoriferous substances, volatile organic compounds, and organic substrate colorants.

Specifically, when the above photocatalyst is exposed to light, electrons and holes generated from energy obtained by absorbing light in a wavelength range of about 400nm to about 700nm generate peroxide anions or hydroxyl radicals or the like, which can degrade and remove harmful substances in the air, thereby playing a role in cleaning the air, deodorizing, or antibacterial.

The photocatalyst may include a metal oxide and metal particles.

Fig. 2 schematically shows the appearance of a photocatalyst according to an example of the present invention.

Referring to fig. 2, the photocatalyst 150 may have a shape in which metal particles 210 are dispersedly attached to the surface of a metal oxide 220. Specifically, the photocatalyst 150 may be in a form in which the metal particles 210 are photo-deposited (photo-deposition) on the surface of the metal oxide 220.

The metal oxide may include one selected from the group consisting of titanium oxide, tungsten oxide, zinc oxide, niobium oxide, and a combination thereof.

For example, the metal oxide may include tungsten oxide, and in this case, the photocatalyst exhibits excellent photocatalytic characteristics and is inexpensive when the reaction is performed under visible light.

For example, the metal particles may contain platinum, and in this case, the advantage of the highest photocatalyst performance can be obtained.

The metal oxide and the metal particles are spherical particles, and "spherical particles" do not mean particles having a mathematically complete spherical shape, but mean particles having a projection image having the same or a shape similar to a circle or an ellipse. The metal oxide and the metal particles are spherical particles, and as a result, the photocatalyst particles have a shape in which spherical metal particles are deposited on the surfaces of the spherical metal oxide particles.

In this case, the particle diameter of the metal particles is several nanometers (nm), and for example, may be about 3nm to about 5 nm. The particle size of the metal particles is very small compared to the particle size of the metal oxide, and the metal particles have the particle size in the above range, thereby being photo-deposited on the surface of the metal oxide in a suitable content, and thus, excellent photocatalytic activity can be exhibited.

The particle size of the metal particles can be derived by measuring the diameter of a projected image obtained by projecting the metal particles with parallel light in a predetermined direction, and this can be applied to the photocatalyst.

The particle size of the above photocatalyst may be about 20nm to about 100nm, specifically, about 30nm to about 60 nm. The particle size of the photocatalyst particles can be derived by measuring a Scanning Electron Microscope (SEM) or Transmission Electron Microscope (TEM) photograph. The photocatalyst particles having a particle size within the above range can ensure high adhesion to the photocatalyst layer and can exhibit excellent photocatalytic activity by being dispersed with an appropriate degree of dispersion.

When the particle size of the metal particles is considered to be very small compared to the particle size of the metal oxide, it is understood that the size of the photocatalyst particles, that is, the particle size of the photocatalyst particles is mainly determined by the particle size of the metal oxide. That is, in the case where the photocatalyst particles have a particle diameter in the above range, the metal oxide of the photocatalyst particles may have several nanometers in the above range, for example, may have a particle diameter in an error range of about 3nm to about 5 nm. In this case, a sufficient amount of metal particles can be photo-deposited on the surface of the metal oxide, and excellent catalytic activity efficiency can be exhibited. The photocatalyst particles have a particle diameter in the above range, and thus can be uniformly distributed in the photocatalyst layer.

The photocatalyst layer may contain the first inorganic binder in an amount of about 50 parts by weight to about 100 parts by weight, based on 100 parts by weight of the photocatalyst.

The photocatalyst layer contains the first inorganic binder in the above weight part range, whereby the function of the photocatalyst is not deteriorated and appropriate hardness can be realized and durability is also improved. When the weight part of the first inorganic binder is less than the above range, a problem may occur that sufficient adhesion between the photocatalyst layer and the photocatalyst layer cannot be secured, and when the weight part of the first inorganic binder is greater than the above range, a large part of the surface of the photocatalyst is covered with the first inorganic binder, and thus the activity of the photocatalyst may be reduced.

Referring to fig. 1, the photocatalyst functional filter 100 includes an adsorbent layer 120 on one side of the photocatalyst layer 110. The adsorbent layer is located between the photocatalyst layer and the substrate layer, and can easily adsorb harmful substances in the air, and the substrate layer and the photocatalyst layer have good compatibility.

In one embodiment of the present invention, the photocatalyst functional filter can perform the above function excellently by controlling the composition and components of the adsorbent.

Specifically, the thickness of the sorbent layer can be from about 0.2um to about 1 um. The adsorbent layer can effectively adsorb harmful substances in the air while maintaining the thickness range, and can have appropriate durability, wherein when the adsorbent layer is smaller than the thickness range, the adsorption performance is reduced, when the adsorbent layer is larger than the thickness range, the adsorbent layer can be cracked to reduce the durability of the adsorbent layer, and the thicker the adsorbent layer is, the higher the production cost is.

The adsorbent layer includes a second inorganic binder different from the first inorganic binder of the photocatalyst layer. The second inorganic binder is a binder different from the first inorganic binder, so that the adsorbent layer and the photocatalyst layer can maintain a separated structure more favorably than the case of using the same binder, the photocatalyst efficiency is maximized by the hydrophilic property of the first inorganic binder included in the photocatalyst layer, and the adsorbent layer can realize uniform coating without cracks and excellent durability by the second inorganic binder included in the adsorbent layer.

The second inorganic binder may include one selected from the group consisting of tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, and a combination thereof. The second inorganic binder allows the adsorbent to be well adhered to the photocatalyst functional filter, and for example, when the second inorganic binder includes an ethyl orthosilicate binder, the second inorganic binder has excellent compatibility with the adsorbent and the first inorganic binder, and can be firmly adhered to the surface of the photocatalyst functional filter without losing the adsorption function of the adsorbent.

The adsorbent layer includes an adsorbent, and the adsorbent may include one selected from the group consisting of activated carbon, zeolite, apatite, alumina, silica, and a combination thereof. With the use of the above-mentioned kind of adsorbent, there is obtained an advantage that excellent compatibility with the second inorganic binder is ensured and harmful substances in the air can be adsorbed quickly.

The adsorbent may have a porous structure. The above adsorbent may have a high surface area by the porous structure, and the larger the surface area may be more advantageous in adsorbing harmful substances in the air. Specifically, the above adsorbent may have about 500m²G to about 1000m²Surface area in g. The adsorbent has a surface area in the above range, so that harmful substances in the air can be adsorbed to the surface of the adsorbent more rapidly.

Further, at least a part of the photocatalyst may be adhered to the surface of the adsorbent.

Specifically, referring to fig. 1, the adsorbent 170 of the adsorbent layer 120 has a structure in which a part thereof is exposed to the outside of the layer. Thereby, at least a part of the adsorbent 170 may be penetrated into the photocatalyst layer 110, and may be adhered to at least a part of the photocatalyst 150. At least a part of the photocatalyst is adhered to the surface of the adsorbent, so that the adsorption speed and degradation speed of harmful substances in the air can be improved.

The particle size of the above adsorbent may be about 0.02 μm to about 1 μm. The particle size of the adsorbent particles satisfies the above range, and thus high adhesion to the adsorbent layer can be ensured, and excellent adsorption can be exhibited by dispersing the particles with an appropriate degree of dispersion. When the particle size of the adsorbent is smaller than the above range, the adsorbent is made smaller than the photocatalyst particles, and in this case, the amount of adsorbent exposed to the outside is small, and it may be difficult to achieve effective adsorption performance, and when the particle size of the adsorbent is larger than the above range, the uniformity and durability of the adsorbent layer may be degraded.

The surface area and the particle size of the adsorbent satisfy the above ranges, respectively, so that the adsorption effect of harmful substances in the air and the improvement effect of mechanical properties such as hardness and durability of the adsorbent layer can be greatly improved.

The adsorbent layer may contain the second inorganic binder in an amount of about 50 parts by weight to about 100 parts by weight based on 100 parts by weight of the adsorbent.

The adsorbent layer contains the second inorganic binder in the above weight part range, whereby the function of the adsorbent layer is not deteriorated and appropriate hardness can be realized and durability can be improved. When the weight part of the second inorganic binder is less than the above range, a problem may occur that sufficient adhesion between the adsorbent layer and the adsorbent cannot be ensured, and when the weight part of the second inorganic binder is greater than the above range, a large part of the surface of the adsorbent is covered with the second inorganic binder, so that adsorption performance of the adsorbent may be lowered.

Referring to fig. 1, the photocatalyst filter 100 includes a base layer 130 on one side of the adsorbent layer 120. The substrate layer may include one selected from the group consisting of a non-woven fabric, a polymer film, a glass substrate, and a combination thereof, and is not limited thereto. For example, the substrate layer may include a nonwoven fabric, in which case the compatibility with the second inorganic binder is good, the second inorganic binder has good adhesion to the nonwoven fabric, and the second inorganic binder is not easily peeled off even by physical impact, so that the durability of the photocatalyst functional filter can be improved.

Specific examples of the present invention are set forth below. However, the following examples are only for specifically illustrating or explaining the present invention and do not limit the present invention.

Preparation example

Preparation example 1: preparation of titanium dioxide Binder

The titania binder sol was prepared by adding isopropyl alcohol (IPA) and Tetraisopropyl Titanate (TTIP) to a beaker, mixing them, and then adding nitric acid.

Preparation example 2: preparation of photocatalyst coating liquid

A plurality of tungsten oxide photocatalysts (Pt/WO3) containing platinum nanoparticles and having a particle diameter within a range of 30nm to 60nm were added to and mixed with the titania binder sol to prepare a photocatalyst coating liquid containing 100 parts by weight of the titania binder based on 100 parts by weight of the tungsten oxide photocatalyst.

Preparation example 3: preparation of tetraethoxysilane binder

After adding ethanol to a beaker and mixing tetraethoxysilane, a solution in which hydrochloric acid and distilled water are mixed is prepared, and the above solution is injected in the form of droplets into the solution in which tetraethoxysilane and ethanol are mixed, thereby preparing an tetraethoxysilane binder sol.

Preparation example 4: preparation of adsorbent coating liquid

Adding and mixing a plurality of zeolites having a particle diameter within a range of 0.02 to 1 μm to the tetraethoxysilane binder sol to prepare an adsorbent coating liquid containing 100 parts by weight of the tetraethoxysilane binder based on 100 parts by weight of the adsorbent.

Preparation example 5: preparation of aqueous photocatalyst solution

A plurality of oxide photocatalysts comprising platinum nanoparticles and having a particle size within a range of 30nm to 60nm are added to an aqueous solution, thereby preparing a 10 weight percent concentration photocatalyst aqueous solution.

Examples and comparative examples

Example 1

The prepared adsorbent coating liquid was coated on one side of a nonwoven fabric having a thickness of 1mm and thermally cured to form an adsorbent layer having a thickness of 500nm, and then the prepared photocatalyst coating liquid was coated and thermally cured to form a photocatalyst layer having a thickness of 500nm, thereby preparing a filter.

Comparative example 1

The prepared adsorbent coating liquid was coated on one side of a nonwoven fabric having a thickness of 1mm and thermally cured to form an adsorbent layer having a thickness of 500nm, thereby preparing a filter.

Comparative example 2

The prepared photocatalyst coating liquid was applied to one side of a 1mm thick nonwoven fabric and thermally cured to form a 500nm thick photocatalyst layer, thereby preparing a filter.

Comparative example 3

The prepared adsorbent coating liquid was coated on one side of a nonwoven fabric having a thickness of 1mm and thermally cured to form an adsorbent layer having a thickness of 500nm, and then the prepared photocatalyst aqueous solution was coated and thermally cured to form a photocatalyst layer, thereby preparing a filter.

Comparative example 4

The prepared adsorbent coating liquid and photocatalyst aqueous solution were mixed and coated on one side of a nonwoven fabric having a thickness of 10mm, followed by thermosetting to form a thermosetting layer having a thickness of 500nm, thereby preparing a filter.

Evaluation of

Experimental example 1: detection of harmful gas degradation performance

The measurement was carried out by the cell test (Small chamber test) method (ISO 18560-1:2014), and a white light emitting diode (white LED) having an injected gas concentration of 0.1ppm and a light source of 1000lux was used. The results are shown in table 1 below.

Experimental example 2: evaluation of surface durability

The mass of the adsorbent or photocatalyst peeled off was measured by adhering a cellophane tape having a length of 5cm and a width of 1.5cm to the surface of the functional filter of each of examples and comparative examples and then peeling off the tape, and the surface durability was good when the amount peeled off was 3% and insufficient when the amount peeled off was more than 3% compared with the mass of the adsorbent or photocatalyst mixed in each of examples and comparative examples, and the results are shown in table 1 below.

TABLE 1

	Degree of degradation of harmful gas	Surface durability
			Example 1	93	Good effect
Comparative example 1	14	Good effect
			Comparative example 2	81	Good effect
Comparative example 3	93	Deficiency of
			Comparative example 4	23	Deficiency of

It was confirmed that the photocatalyst functional filter prepared according to example 1 achieved an excellent harmful gas degradation function, achieved a harmful gas degradation performance of more than 90, and good surface durability, thereby achieving optimum physical properties as a photocatalyst functional filter.

In contrast, it was confirmed that the functional filters prepared according to comparative examples 1 to 4 failed to satisfy both the harmful gas degradation function of 90 or more and the good surface durability.

Specifically, in the case of comparative example 1, it was confirmed that the filtering treatment was performed only by the adsorbent coating liquid without the photocatalyst, and the harmful gas degradation performance was remarkably lowered. In the case of comparative example 4, it was confirmed that the tetraethoxysilane contained in the adsorbent coating liquid was exposed to the surface and the hydrophilic surface was difficult to form, thereby limiting the expression of the photocatalyst performance.

In the case of comparative example 3, it was confirmed that the surface durability was decreased by including the photocatalyst aqueous solution instead of the photocatalyst binder.

Description of the reference numerals:

100: photocatalyst functional filter

110: photocatalyst layer

120: adsorbent layer

130: substrate layer

140: first inorganic binder

150: photocatalyst and process for producing the same

160: second inorganic binder

170: adsorbent and process for producing the same

210: metal particles

220: metal oxides

Claims

1. A photocatalyst functional filter characterized in that,

sequentially comprises a photocatalyst layer, an adsorbent layer and a base material layer,

the photocatalyst layer includes:

a first inorganic binder having hydrophilicity; and

a photocatalyst is used as a light source for the light,

the adsorbent layer includes:

a mixture of a second inorganic binder and an adsorbent;

wherein the first inorganic binder comprises one selected from the group consisting of a titanium dioxide binder, colloidal silica, a silica binder, an alumina sol, a zirconia sol, and combinations thereof;

wherein the photocatalyst comprises a metal oxide and metal particles;

wherein the above metal oxide comprises one selected from the group consisting of tungsten oxide, niobium oxide, and a combination thereof;

wherein the metal particles comprise one selected from the group consisting of tungsten, chromium, vanadium, molybdenum, copper, iron, cobalt, manganese, nickel, platinum, gold, silver, cerium, cadmium, zinc, magnesium, calcium, strontium, barium, and combinations thereof,

wherein the second inorganic binder comprises a thermosetting material selected from a sol of tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane and combinations thereof;

wherein the adsorbent comprises one selected from the group consisting of activated carbon, zeolite, apatite, silica, and combinations thereof;

wherein the thickness of the photocatalyst layer is 0.2 to 1 μm; and

wherein the thickness of the adsorbent layer is 0.2 μm to 1 μm.

2. The photocatalyst-functional filter as claimed in claim 1, wherein the contact angle between the first inorganic binder and water is 0 ° to 20 °.

3. The photocatalyst-functional filter as claimed in claim 1, wherein the photocatalyst has a particle size of 20nm to 100 nm.

4. The photocatalyst-functional filter as claimed in claim 1, wherein the first inorganic binder is contained in the photocatalyst layer in an amount of 50 to 100 parts by weight based on 100 parts by weight of the photocatalyst.

5. The photocatalyst-functional filter according to claim 1, wherein the adsorbent has a particle size of 0.02 to 1 μm.

6. The photocatalyst-functional filter according to claim 1, wherein the second inorganic binder is contained in the adsorbent layer in an amount of 50 to 100 parts by weight based on 100 parts by weight of the adsorbent.

7. The photocatalyst-functional filter according to claim 1, wherein the substrate layer comprises a nonwoven fabric.