KR102279008B1 - Window system comprising visible light active photocatalyst for air cleaning - Google Patents

Abstract

The present invention relates to windows and doors, and the windows and doors for air purification comprising a visible light active photocatalyst according to one aspect of the present invention include a photocatalyst provided on at least one side of the window in the window and door provided on the window frame, the photocatalyst , which includes an inorganic oxide and a metal oxide layer derived from an organometallic compound formed on the inorganic oxide, and has photoactivity in a visible ray region of 400 nm or more.

Description

Window and door for air purification containing visible light active photocatalyst {WINDOW SYSTEM COMPRISING VISIBLE LIGHT ACTIVE PHOTOCATALYST FOR AIR CLEANING}

The present invention relates to a window installed on a window frame, and more particularly, to a window type air purification system capable of purifying indoor air.

In recent years, the awareness of the importance of the indoor environment and air quality is being reconsidered with the increase in indoor activity time and the tendency of building density. In a residential type where high-rise buildings such as apartments and officetels are dense, it is extremely difficult to open windows due to concerns about the influx of polluted air from the outside into the room. Accordingly, unless a separate ventilation means is provided, the quality of the air in the room cannot be avoided.

As a conventional means for ventilation and air purification, an air purifier has been developed and marketed for the purpose of purifying air containing various pollutants such as exhaust gas and fine dust discharged from mechanical devices such as automobiles when it enters the room. The effectiveness of these air purifiers is questionable because they purify polluted air introduced through windows and the like and simply circulate repeatedly indoors while blocking the continuous inflow of fresh outside air.

In addition, since such an air purifier must be provided with a device for air intake and exhaust, there is a problem such as occupying a space installed indoors and hindering the interior.

Some technologies, such as Korean Patent Application Laid-Open No. 10-2004-75686, disclose a window equipped with a ventilation device, but these technologies are basically a facility provided on a window frame due to a device such as a partition wall or a fan installed in the window. There was a problem that the volume of itself increased and the air could not be purified practically.

Accordingly, there has been a demand for a technology capable of purifying incoming air or air present in a room with high efficiency without occupying a volume.

On the other hand, a photocatalyst has catalytic activity by absorbing light energy, and oxidatively decomposes environmental pollutants such as organic substances with strong oxidizing power by catalytic activity. That is, the photocatalyst is irradiated with light (ultraviolet rays) having energy greater than or equal to the band gap to cause electron transition from the valence band to the conduction band, and a hole is formed in the valence band. These electrons and holes diffuse to the surface of the powder, and in contact with oxygen and moisture, they cause a redox reaction or recombine to generate heat. That is, electrons in the conduction band reduce oxygen to generate superoxanions, and holes in the valence band oxidize moisture to form hydroxyl radicals (OH·). Due to the strong oxidizing power of hydroxy radicals (OH·) generated by these holes, it is possible to exhibit gaseous or liquid organic substances adsorbed on the surface of the photocatalyst, that is, decomposition, sterilization power, hydrophilicity, etc. In general, titanium dioxide (TiO ₂ ) powder is used as a photocatalyst, and titanium dioxide (TiO ₂ ) is harmless to the human body, has excellent photocatalytic activity, has excellent light corrosion resistance and is inexpensive. Titanium dioxide (TiO ₂ ) absorbs and reacts with ultraviolet rays of 388 nm or less to generate electrons (conduction band) and holes (valence band). Artificial lighting, light emitting diodes, etc. may be used. Electrons and holes generated in the reaction ^{recombine in 10 -12} to 10 ^-9 seconds, but if contaminants or the like are adsorbed to the surface before recombination, they are decomposed by the electrons and holes. However, since the band gap energy (wavelength of 380 nm or more) of the titanium dioxide (TiO ₂ ) powder is obtained from sunlight, about 2% of that light can be used, so it has a smooth catalytic activity in the visible region (400-800 nm), which is the main wavelength of sunlight have difficulty having That is, until to sensitive to visible light, it is essential inde titanium dioxide (TiO ₂₎ a visible light sensitive on the type photocatalytic efficiency of the powder to effectively separate the electron / hole pairs generated by the light absorption to reduce the photocatalyst according to the band gap effectively, yet It was a situation that did not reach the level for commercialization in the air cleaning field.

The present invention solves the above-mentioned demand for indoor air purification, and relates to a new concept window that can purify indoor air or incoming air and automatically remove harmful substances without a separate complicated device.

The present invention is to solve all of the air pollution in modern society, supplementation for insufficient functions of photocatalysts, etc., and the present invention has excellent photocatalytic activity in the visible light region, formed by introducing a doping process of an organometallic compound, Developed an inorganic oxide-based photocatalyst and used it for windows and windows.

One embodiment of the present invention is to form a coating layer on a part of the window and door using a newly developed photocatalyst activated in visible light, and another embodiment of the present invention includes an air purification unit including a photocatalyst on the surface of the window will do

One embodiment of the present invention is to provide a window that contains an inorganic oxide-based photocatalyst and has a function of purifying the surrounding air even when exposed to light by having a photolysis function. This technology is in line with the recent trend of development of various facilities to reduce environmental pollution, and solves all the problems of modern people's desire for air purification and photocatalysts that were difficult to commercialize.

According to an embodiment of the present invention, to provide a technology for removing harmful substances in the surrounding air by simply installing the windows and doors of the present invention on a window frame without a separate air purifier, and furthermore, to provide a technology for allowing purified air to flow in it is for

However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

The windows and doors for air purification comprising a visible light active photocatalyst according to an aspect of the present invention include a photocatalyst provided on at least one surface of the windows and doors provided on a window frame, wherein the photocatalyst is an inorganic oxide and the inorganic oxide It includes an organometallic compound-derived metal oxide layer formed thereon, and has photoactivity in the visible light region of 400 nm or more.

According to an embodiment of the present invention, it may further include a photocatalyst coating layer provided on at least one surface of the window, wherein the photocatalyst may be dispersedly formed in the photocatalyst coating layer.

According to an embodiment of the present invention, the windows and doors for air purification further include an air purification unit provided on at least one surface of the window and door, wherein the air purification unit includes a filter having a plurality of pores, and the photocatalyst may be dispersed in the filter.

According to an embodiment of the present invention, the filter includes a filter member including a porous nano-web; and a support member mounted on an edge of the porous nanoweb to support the filter member.

According to an embodiment of the present invention, the window for air purification may further include a blowing unit for introducing air into the room.

According to an embodiment of the present invention, the metal oxide layer may include iron oxide derived from ferrocene.

According to an embodiment, the inorganic oxide includes at least one selected from the group consisting of oxides including at least one of Ti, Zn, Al and Sn, and the metal oxide layer has 0.001 to 10 weight compared to the inorganic oxide. % of iron oxide, and the photocatalyst may have photoactivity in dry conditions of 30% or less of humidity.

According to an embodiment, the photocatalyst may have photoactivity in a dry condition of 30% or less of humidity.

According to an embodiment, the inorganic oxide does not include an inorganic oxide including iron, and the metal oxide layer may be a heat treatment of ferrocene deposited on the inorganic oxide.

According to an embodiment, the metal oxide may include one or more of the compounds represented by the following Chemical Formula 1.

[Formula 1]

Me _x O _Y H _Z

(Me is at least one metal element in Groups 1 to 3, and X, Y and Z are each selected from 0 to 3, and X and Y are not 0.)

According to an embodiment, the specific surface area of the photocatalyst may be 5 (m ² /g) or more, and the average pore size may be 50 nm or less.

According to another aspect of the present invention, there is provided an air purification system including the window.

According to an embodiment of the present invention, there is provided a window including a photocatalytic coating layer, and such a window blocks the outdoor and indoor parts of a building during the opening and closing process and, in addition to the original function of circulating air, only the window exposure to visible light This can have the effect of reducing harmful substances in the surrounding air.

More specifically, according to an embodiment of the present invention, an inorganic oxide-based photocatalyst having excellent photocatalytic activity in the visible light region and excellent photolysis efficiency in various humidity and temperature regions can be prepared, and a window to which this photocatalyst is applied. have.

The windows and doors proposed in the present invention contain a photocatalyst that is activated even in the visible light region and low humidity environmental conditions, so that the surrounding air can be purified even in various exposure environments.

The window and door including the visible light activated photocatalyst proposed in the present invention may be one in which the photocatalyst is activated by receiving light including the visible light region. Through this, the window proposed by the present invention alleviates modern people's fear of air pollution, and it is possible to purify the surrounding air without the need for a separate air purifier, so it is suitable for various environments where structures for noise reduction can be applied. It can be applied universally.

Since windows and doors are usually installed in an area where light enters well, the windows and doors equipped with a photocatalyst proposed in the present invention can faithfully achieve the function of air purification just by being installed on window frames provided inside and outside the building. .

The present invention can provide a window including an inorganic oxide-based photocatalyst manufactured by a simple and economical method, and the window and door including the inorganic oxide-based photocatalyst contains a photocatalyst that can be activated even under dry conditions, , it has the ability to decompose volatile organic compounds with high efficiency and excellent stability in response to light in the visible region.

Specifically, the photocatalyst proposed in one embodiment of the present invention is not only used for manufacturing windows and doors for outdoor use, but also for various areas to which windows are applied, such as windows for indoor use, exterior walls or interior walls of buildings, and windows provided in areas requiring various shielding facilities. The possibility of multiple application is not excluded.

1 is a flowchart showing a method of manufacturing a photocatalyst applied to the present invention, according to an embodiment of the present invention.
2 exemplarily shows the configuration of a TR-CVD reactor used in a process for manufacturing a photocatalyst applied to the present invention, according to an embodiment of the present invention.
FIG. 3 exemplarily shows a manufacturing process of a photocatalyst applied to the present invention according to an embodiment of the present invention.
4 shows an image of a photocatalyst applied to the present invention prepared according to an embodiment of the present invention.
5 shows a TEM image of a photocatalyst prepared according to an embodiment of the present invention.
6 shows the evaluation results of the photolysis performance of the photocatalyst prepared according to the embodiment of the present invention.
7 shows the evaluation results of the photolysis performance according to the humidity of the photocatalyst prepared according to the embodiment of the present invention.
8 shows the stability evaluation results of photolysis performance according to repeated photolysis experiments of the photocatalyst prepared according to an embodiment of the present invention.
9 is a structural diagram schematically showing the structure of a window including a window including a photocatalyst manufactured according to an embodiment of the present invention.
10 is a diagram showing a schematic structure of a window for air purification including a visible light active photocatalyst formed according to an embodiment of the present invention.
11 is a diagram showing a schematic structure of an air purification unit applicable to windows and doors according to an embodiment of the present invention.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

Various modifications may be made to the embodiments described below. It should be understood that the embodiments described below are not intended to limit the embodiments, and include all modifications, equivalents or substitutes thereto.

Terms used in the examples are only used to describe specific examples, and are not intended to limit the examples. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the possibility of addition or existence of numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiment belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

In addition, in the description with reference to the accompanying drawings, the same components are assigned the same reference numerals regardless of the reference numerals, and the overlapping description thereof will be omitted. In the description of the embodiment, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the embodiment, the detailed description thereof will be omitted.

In addition, the terms used in this specification are terms used to properly express the preferred embodiment of the present invention, which may vary according to the intention of the user or operator or customs in the field to which the present invention belongs. Accordingly, definitions of these terms should be made based on the content throughout this specification. Like reference numerals in each figure indicate like elements.

Throughout the specification, when a member is said to be located “on” another member, this includes not only a case in which a member is in contact with another member but also a case in which another member is present between the two members.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components.

Hereinafter, windows and doors including the photocatalyst of the present invention will be described in detail with reference to examples and drawings. However, the present invention is not limited to these examples and drawings.

One embodiment of the present invention may relate to a window that can perform a function of purifying the surrounding air only by actually installing photocatalyst particles in the coating layer of the window and being exposed to light.

Another embodiment of the present invention may relate to windows and doors in which photocatalyst particles are dispersedly formed in the filter of the air purification unit of the window and perform the function of purifying the surrounding air by the air that has passed through the filter.

Unlike conventional photocatalysts, the photocatalyst applied to the windows and doors of the present invention can be sufficiently activated even when exposed to light in the visible range without being irradiated with a wavelength in the ultraviolet range. Therefore, it is possible to purify the air in the surrounding space with high efficiency without a special driving device by itself by being exposed to sunlight outdoors or indoors.

The present inventor confirms that this effect can be realized through a photocatalyst including a metal oxide layer formed by heat treatment of an organometallic compound, and develops and proposes a window capable of maximizing the characteristics of such a photocatalyst .

The present invention can be expected to purify the surrounding air in addition to the sound absorption and sound shielding functions of general windows.

The photocatalyst applied to an example of the present invention is activated only in the ultraviolet region and improves the problem of the conventional photocatalyst, which is difficult to commercialize, and is sufficiently activated in the visible light region of 400 nm or more. The photocatalyst applied to the present invention can exhibit its function even if it is installed in an indoor or outdoor environment that can receive sunlight. Since most windows are installed in an environment where external natural light enters, this photocatalyst can be expected to have a synergistic effect that can effectively purify the surrounding air just by being provided on the windows.

The photocatalyst may include an inorganic oxide and a metal oxide layer formed thereon. In this case, including the inorganic oxide and the metal oxide layer is referred to as a photocatalyst. The photocatalyst may or may not be in the form of particles. Unlike conventional photocatalysts, the photocatalyst is characterized in that it reacts with a wavelength of 400 nm or more in the visible light region to have active photoactivity. This may be an effect realized in the metal oxide layer derived from the organometallic compound.

The photocatalyst particles may be formed on the outer surface coating layer exposed to light of the window.

10 is a diagram showing a schematic structure of a window for air purification including a visible light active photocatalyst formed according to an embodiment of the present invention.

Hereinafter, with reference to the structure of the window for air purification of FIG. 10, the window for air purification including the visible light active photocatalyst provided in an embodiment of the present invention will be described in detail.

The window and door 100 for air purification including a visible light active photocatalyst according to one aspect of the present invention includes a photocatalyst provided on at least one surface of the window and door window 110 in the window provided on the window frame, wherein the photocatalyst is , which includes an inorganic oxide and a metal oxide layer derived from an organometallic compound formed on the inorganic oxide, and has photoactivity in a visible light region of 400 nm or more.

The "on one surface" means may be in contact with one surface, or may be provided spaced apart by a predetermined interval or more. The window is formed on the frame 120 forming the opening of the window and means a surface that cuts off the inside of the window and the outside of the window. The windows and doors may be formed of a material including glass, but the material is not limited in the present invention as long as it is a material known to form a window in general.

The photocatalyst, which includes a metal oxide formed from an organometallic compound, can purify ambient air by having photoactivity just by being exposed to light in the visible region even if it does not receive light in the ultraviolet region.

The photocatalyst may be provided on one side or both sides of a side forming a window of a window installed on a window frame. The photocatalyst may be provided in the form of particles, and as another example, it may exist in the form of a cured gel by forming a dispersion with other compositions.

According to an embodiment of the present invention, it may further include a photocatalyst coating layer provided on at least one surface of the window, wherein the photocatalyst may be dispersedly formed in the photocatalyst coating layer.

In one embodiment, the indoor air purification performance may be provided by forming a coating layer including the photocatalyst developed in the present invention on at least one surface of the windows.

According to one embodiment, the coating layer may be to form a thickness of 0.01 mm to 5 mm on the surface of the window. Preferably, the coating layer may be formed to have a thickness of 0.1 mm to 1 mm on the substrate. If the thickness of the coating layer is too thin, it is difficult to realize the sufficient air purifying effect of the photocatalyst, and if it is too thick, the cost may increase and the air purifying effect may be saturated.

At least one surface on which the photocatalytic coating layer is formed may include a surface formed toward the interior of the window. In this way, when the coating layer is formed on the surface of the window formed toward the interior, purification of the indoor air may be implemented in a state in which the window is closed.

11 is a diagram showing a schematic structure of an air purification unit applicable to windows and doors according to an embodiment of the present invention.

Hereinafter, an example of a window equipped with an air purification unit according to another aspect of the present invention will be described.

According to an embodiment of the present invention, the windows and doors for air purification further include an air purification unit 200 provided on at least one surface of the windows and doors, and the air purification unit includes a filter 210 having a plurality of pores. Including, the photocatalyst may be formed dispersed in the filter. The filter may be provided in an opening formed in the center of the frame 220 formed around the filter.

According to an example, the window and door for air purification may be provided to purify the air flowing into the window even when the window is open.

The air purification unit may have a structure that can be opened or closed separately from the opening and closing structure of the frame of the window. As an example, the window of the window may be formed to include a glass material, and the air purifying unit may form a unit independent of the window of the window. As an example, the air purification unit may form an independent frame 220 like an insect screen structure, so that even if the window surface of the window is opened, the air purification unit may still have a structure that blocks the window. The air purifying unit may be provided with a structure for introducing external air to the inside.

As an example, the window and door window of the window for air purification may be formed as an opening without forming a blocked surface such as glass, and the air purification unit may be provided in the opening. In this case, the windows and doors for air purification may be formed of windows filled with only the air purification unit.

According to an embodiment of the present invention, the filter includes a filter member including a porous nano-web; and a support member mounted on an edge of the porous nanoweb to support the filter member.

According to one embodiment, the filter member may be formed to include a pleated shape for expanding the contact area with air. The filter member may be formed by an electrospinning method.

As an example, the filter member may be to make a composition solution for electrospinning by mixing an electrospinning polymer material with an organic solvent in a certain ratio, and then electrospinning the composition solution to make nanofibers. Then, after dispersing the photocatalyst on the nanofibers, the nanofibers are accumulated to prepare a porous nanoweb having micropores.

In this case, the nanofiber diameter may be 0.5 μm to 3 μm. The nanoweb may have a thickness of 1 μm to 10 μm. The diameter of the nanofiber and the thickness of the nanoweb are highly related to the air permeability of the window. If the fiber diameter is smaller than the above numerical range or is formed with a higher thickness, there may be a problem in that the amount of air introduced into the room decreases, and when it is formed with a thickness lower than the above-mentioned thickness, purification of the air flowing into the room is sufficiently performed it may not be possible The preferable air permeability of the nanoweb may be 5 CFM to 40 CFM level.

As an example, the nanoweb may include a honeycomb structure.

As an example, the filter member may be formed of a non-woven fabric material, a fabric having pores, or a mesh material. As an example, the support member may be formed to include a resin material including a polymer of various materials and a metal material including a metal component.

According to an embodiment of the present invention, the window for air purification may further include a blowing unit (not shown) for introducing air into the room.

The blower unit may simultaneously serve as a pump for introducing external air from one side of the window of the window and as a pump for discharging purified air from the other side of the window.

According to an embodiment, the metal oxide layer may include iron oxide derived from ferrocene.

According to an embodiment, the inorganic oxide includes at least one selected from the group consisting of oxides including at least one of Ti, Zn, Al and Sn, and the metal oxide layer has 0.001 to 10 weight compared to the inorganic oxide. % of iron oxide, and the photocatalyst may have photoactivity in dry conditions of 30% or less of humidity.

According to an embodiment, the photocatalyst may include: an inorganic oxide; and a metal oxide layer formed on the inorganic oxide. may include.

The inorganic oxide may include at least one selected from the group consisting of oxides including at least one of Ti, Zn, Al, and Sn.

The metal oxide layer may include a ferrocene-derived iron oxide layer. At this time, the content of iron may be 0.001 to 10% by weight relative to the inorganic oxide, preferably 0.001 to 5% by weight relative to the inorganic oxide.

The inorganic oxide is an inorganic semiconductor compound exhibiting catalytic activity by absorbing light energy, for example, Ti, Zn, Al, Fe, W, Sn, Bi, Ta, Cu, Si, Ru, Sr, Ba and Ce. It is an oxide containing at least one selected from the group consisting of, preferably Ti, Zn, Al and Sn. Specifically, TiO ₂ , Al ₂ O ₃ , ZnO ₂ , ZnO, SrTiO ₃ , Fe ₂ O ₃ , Ta ₂ O ₅ , WO ₃ , SnO ₂ , Bi ₂ O ₃ , NiO, Cu ₂ O, SiO, SiO ₂ , MoS ₂ , InPb, RuO ₂ , CeO ₂ , and the like. In addition, a semiconductor compound such as CdS, GaP, InP, GaAs, or InPb may be further included in addition to the oxide.

According to an embodiment, the inorganic oxide may include at least one selected from the group consisting of beads, powders, rods, wires, needles and fibers, and the inorganic oxide may have a size of 1 nm to 500 μm.

The inorganic oxide includes at least one selected from the group consisting of beads, powders, rods, wires, needles and fibers, and the size of the inorganic oxide is 1 nm or more; more than 10 nm; 30 nm to 500 μm; 30 nm to 100 μm; or 30 nm to 1 μm. The size may mean a diameter, thickness, length, etc. depending on the shape.

According to an embodiment, the inorganic oxide does not include an inorganic oxide including iron, and the metal oxide layer may be a heat treatment of ferrocene deposited on the inorganic oxide.

As an example, the metal oxide layer derived from the metal organic compound may be formed by a ferrocene doping process. For example, the ferrocene layer formed on the inorganic oxide may be thermally decomposed to thermally decompose, and iron oxide converted from ferrocene by the thermal decomposition process may be included. The doping process of the organometallic compound will be described in more detail in the following manufacturing method.

The metal oxide layer derived from the organometallic oxide may be, for example, an iron oxide derived from at least one of ferrocene and a ferrocene derivative. The ferrocene derivative is, ferrocene aldehyde, ferrocene ketone, ferrocene carboxylic acid, ferrocene alcohol, phenol or ether compound, nitrogen-containing ferrocene compound, sulfur-containing ferrocene compound, phosphorus-containing ferrocene compound, silicon-containing ferrocene compound, 1,1' - From the group consisting of dicopper ferrocene (1,1'-di-copper ferrocene), ferrocene boric acid, ferrocenyl cuprous acetylide and bisferrocenyl titanocene It may include at least one selected.

As an example, the metal content in the metal oxide layer derived from the organometallic compound is 0.001 to 10% by weight compared to the inorganic oxide; 0.01 to 10% by weight; 0.01 to 3% by weight; 0.01 to 1.5% by weight; Or 0.01 to 1% by weight may be included. When included within the above range, it is possible to increase the photocatalytic activity in the visible light region to improve the photolysis efficiency. In addition, when the content of the metal increases, absorption of the visible light region may increase, but since a decrease in photocatalytic activity may occur due to the increase in the content of the metal, it is preferable to include the content of the metal within the above range, and more preferably, the The metal may be iron, and the iron content may be 0.01 to 5 wt%.

As an example, the metal oxide layer derived from the organometallic compound may have a thickness of 0.01 nm or more; 0.1 nm or greater; more than 10 nm; Or it may have a thickness of 1 nm to 100 nm. When included in the above thickness range, it is possible to prevent a decrease in the porosity of the photocatalyst according to the increase in the thickness of the coating layer, and to increase the amount of moisture, OH- ions, decomposition target, etc. adsorbed to the surface to improve the photolysis performance. In addition, the metal oxide layer derived from the organometallic compound, 0.01 nm or more; 0.1 nm or greater; more than 10 nm; Or it may include a ferrocene-derived iron oxide having a size of 1 nm to 100 nm. The size may mean length, diameter, thickness, etc. depending on the shape.

According to an embodiment, the inorganic oxide does not include an inorganic oxide including iron, and the iron oxide layer may be a heat treatment of ferrocene deposited on the inorganic oxide.

The metal oxide may include one or more of the compounds represented by the following Chemical Formula 1.

[Formula 1]

Me _x O _Y H _Z

Here, Me is at least one of metal elements corresponding to Groups 1 to 3, X, Y and Z are each selected from 0 to 3, and X and Y are not 0.

As an example, the Z may also be non-zero.

_{As an example, iron oxide (Fe x} O _y H _z ), a semiconducting material that absorbs light in the visible region and is stable and cheap, _{is introduced into the TiO 2} surface in the form of nano-sized particles to form a photocatalyst that responds to visible light. can be formed

According to an embodiment of the present invention, the photocatalyst absorbs light so that a wavelength region exhibiting a photoreaction may be extended from an ultraviolet ray to a visible ray region. The photocatalyst may exhibit much superior photocatalytic activity compared to conventional photocatalysts, particularly in the visible light region of 400 nm or more. In addition, the photocatalytic reactivity capable of adsorbing and decomposing the decomposition target on the surface is improved, so that it has photocatalytic activity in various humidity ranges, and can exhibit excellent photocatalytic activity even in dry conditions of 30% or less of humidity.

According to one example, the photocatalyst particles, 5 (m ² /g) or more; 5 (m ² /g) to 1000 (m ² /g); or a specific surface area of 5 (m ² /g) to 100 (m ² /g), and an average pore size of 50 nm or less. By introducing the metal oxide derived from the organometallic compound on the surface of the inorganic oxide, the amount of adsorption of the decomposition target on the surface of the photocatalyst increases, and the photocatalytic efficiency can be improved by increasing the photolysis reactivity.

According to an embodiment of the present invention, the photocatalyst is applied to the decomposition of various harmful substances, that is, it can be used to treat environmental pollutants, odor substances, organic compounds, acid gases, and the like. For example, it is used for adsorption and/or photolysis of at least one of gas, liquid, and solid material, and may exhibit photoactivity by light energy including various rays such as a halogen lamp, a xenon lamp, sunlight, and a light emitting diode. More specifically, as the gas, acidic and basic gas, acetaldehyde, VOC (Volatile Organic Compounds) such as ketones, aromatic hydrocarbons and aliphatic hydrocarbons (Paraffin-based and Olefin-based) hydrocarbons, ozone gas, organic and inorganic glass gas, and more specifically, carbon dioxide, carbon monoxide, NOx, SOx, HCl, HF, NH ₃ , methylamine, formaldehyde, hydrogen sulfide, amine, methylmergaptan, hydrogen, oxygen, nitrogen, methane, paraffin , olefins, and the like. Examples of the liquid include formaldehyde, acetaldehyde, benzene, toluene, MEK (Methyl Ethyl Ketone), trichloroethylene, disinfectant, gasoline, diesel, oil, alcohol, Phenol, dye, and the like, and the solid may include, but is not limited to, transition metals, noble metals such as Pt and Pd, ions and/or particles such as Hg and Cr, and nanoparticles of 100 nm or less.

A window comprising a visible light active photocatalyst according to another aspect of the present invention includes one or more windows and doors corresponding to an embodiment of the present invention, wherein the windows and doors are dry conditions of 30% or less humidity and visible light of 400 nm or more It contains a photocatalyst having photoactivity in the region.

According to another aspect of the present invention, it includes providing an air purification system including the window.

1 is a flowchart illustrating a method for manufacturing a photocatalyst according to the present invention, according to an embodiment of the present invention. According to an example, after the photocatalyst is manufactured in the manner shown in FIG. 1, the window and door on which the coating layer containing the photocatalyst according to an embodiment of the present invention is formed by mixing and dispersing the photocatalyst in the process of manufacturing the windows and doors described above can be manufactured.

Hereinafter, with reference to FIG. 1, a description will be given of a method for producing a photocatalyst exhibiting the visible light activity, which is a characteristic technique of the present invention.

The method for preparing the photocatalyst includes: preparing an inorganic oxide; forming a metal oxide layer on the inorganic oxide; and forming an organometallic oxide-derived metal oxide layer by heat-treating after the forming of the metal oxide layer.

The step of preparing the inorganic oxide is a step of preparing an inorganic oxide dispersion or applying an inorganic oxide on a substrate, and the dispersion is an aqueous solvent, an oily solvent, or a mixture of both, and the substrate is a silicon substrate , a wafer, a glass substrate, a semiconductor substrate, a metal substrate, and the like. The inorganic oxide may be applied by spin coating, roll coating, spray coating, dip coating, flow coating, doctor blade method, or the like.

In the forming of the organometallic oxide layer, an organometallic oxide film may be formed using a wet coating method, a sputtering method, or a deposition method. As an example, the organometallic oxide layer may be a ferrocene layer. Preferably, a deposition method such as ALD (atomic layer deposition) or CVD (temperature-regulated chemical vapor deposition) is used, and more preferably, TR-CVD (temperature-controlled chemical vapor deposition) is used. A ferrocene layer can be formed. As an example, when TR-CVD is applied, the amount of iron oxide deposited on the inorganic oxide can be easily controlled by adjusting the amount of ferrocene, and the photocatalyst can be manufactured by simplifying the manufacturing process and efficiently providing the photocatalyst.

The step of forming the organometallic oxide layer is carried out at room temperature to 120 °C, preferably from 40 °C to 100 °C; More preferably, it may be carried out at 60 °C to 100 °C. That is, when TR-CVD is applied, it may be carried out at 60°C to 100°C in order to induce deposition by the vaporization process of the organometallic oxide layer.

The step of forming the organometallic oxide layer is carried out in an air or oxygen atmosphere under atmospheric conditions, and may further include an inert gas.

The organometallic oxide layer in the step of forming the organometallic oxide layer contains 0.01 wt% to 20 wt% of ferrocene compared to the inorganic oxide, and the ferrocene layer may be formed.

The forming of the organometallic oxide-derived metal oxide layer may include, for example, partially or completely oxidizing the organometallic oxide layer to a metal oxide through heat treatment, and removing impurities such as carbon residues.

Forming the organometallic oxide-derived metal oxide layer may include: 50° C. to 900° C.; or 100°C to 800°C; It can be heat treated in two or more steps at a temperature.

For example, the step of forming the organometallic oxide-derived metal oxide layer comprises the step of performing a first heat treatment at a temperature of 100 °C to 300 °C and a second heat treatment at a temperature of 300 °C to 900 °C, each step is They can be heat treated at different temperatures. Each of the above steps is carried out for 1 minute to 20 hours, respectively, in air, 20% or more; It may be carried out in an air or inert gas atmosphere containing 40% or more oxygen.

That is, the first heat treatment may be an annealing process for depositing a metal oxide that is converted into a metal oxide by a reaction between the organic metal oxide and oxygen. The second heat treatment step is a post heat treatment step after the first heat treatment step, and may be an annealing step for improving the activity and performance of the photocatalyst by removing impurities such as carbides.

Hereinafter, the present invention will be described in more detail by way of Examples and Comparative Examples.

Preparation and characterization of photocatalysts

First, a photocatalyst, which is a characteristic component of the present invention, was prepared using ferrocene.

However, the following examples are introduced to prove the manufacturing process of the photocatalyst of the present invention and the effects realized therefrom, and are only examples by selecting ferrocene as the organometallic oxide, and the content of the present invention is limited to the following examples it is not going to be

Example 1

With reference to Fig. 2 of the TR-CVD (temperature controlled chemical vapor deposition) reactor, utilizing a temperature controlled chemical vapor deposition as shown in Figure 3 produce a photocatalyst (Fe-TiO ₂₎ of the iron oxide particles in the nano-scale deposited on the TiO ₂ did. More specifically, 0.02 g of Ferrocene, a precursor of iron, was placed in a vessel made of Quartz on the inner bottom of a reactor made of stainless steel surrounded by a heating band. After placing 3 g of TiO ₂ (TiO ₂ , P-25, Evonik, particle size: 25 nm) in a container made of stainless steel wire mesh in the center of the reactor, the reactor is sealed using polyimide tape. The ferrocene deposition process was carried out by a TR-CVD vaporization process at a temperature of 60 °C for 2 hours in the reactor, and then, the temperature was raised to 200 °C and maintained for 12 hours to convert to iron oxide.

Then prepare a final iron oxide -TiO ₂ hybrid photocatalytic nano-structure (or, expressed as Fe-TiO ₂₎ by an additional heat treatment for 2 hours at 750 ℃ in dry air gas atmosphere to remove the TiO _2. The content of iron deposited on _{TiO 2} under these conditions is about 0.09 wt%.

Example 2

_{An iron oxide-TiO 2} hybrid nanostructure photocatalyst was prepared in the same manner as in Example 1 except that 0.05 g of the iron precursor Ferrocene was applied. The content of iron deposited on _{TiO 2} under these conditions is about 0.13 wt%.

Example 3

_{A photocatalyst having an iron oxide-TiO 2} hybrid nanostructure was prepared in the same manner as in Example 1, except that 0.1 g of the iron precursor Ferrocene was applied. The content of iron deposited on _{TiO 2} under these conditions is about 0.65 wt%.

Example 4

_{A photocatalyst having an iron oxide-TiO 2} hybrid nanostructure was prepared in the same manner as in Example 1, except that 0.3 g of the iron precursor Ferrocene was applied. The content of iron deposited on _{TiO 2} under these conditions is about 1.81 wt%.

4 shows an image of a photocatalyst applied to the present invention prepared according to an embodiment of the present invention.

The prepared photocatalyst (Fe-TiO ₂ ) was shown in FIG. 4 by comparing the transparency and color with _{the TiO 2} photocatalyst coated with general iron oxide. Referring to FIG. 4 , the photocatalyst (Fe-TiO ₂ ) coated with ferrocene-derived iron oxide according to the present invention is transparent and softer than the photocatalyst (Fe ₂ O ₃ -TiO ₂ ) coated with iron oxide (Fe ₂ O _{3 )} It can be seen that it has a yellow color.

A TEM image (image measured with a transmission electron microscope) of the prepared photocatalyst (Fe-TiO _{2 ) was measured and shown in FIG. 5 .} In FIG. 5 , as the iron content decreases, the size of the iron oxide particles deposited on _{the Fe—TiO 2 surface decreases.}

Table 1 shows the specific surface area (BET) and BJH average pore size of the prepared photocatalyst (Fe-TiO _{2 ) through nitrogen adsorption analysis.}

0.13 wt% Fe-TiO ₂ 0.65 wt% Fe-TiO2 1.81 wt % Fe-TiO ₂ BET Surface area (m ² /g) 11.6259 10.3426 8.3939 BJHAdsorption average pore size(nm) 13.2 12.5 13.9

Referring to Table 1, it can be seen that the specific surface area and average pore size do not change significantly even when the iron content of _{Fe-TiO 2} is changed, and it can be confirmed that the mesopores of _{Fe-TiO 2 are formed.}

Evaluation Example 1

_{The photocatalyst (Fe-TiO 2} ) of Example 1 was placed in a 5.3 L batch reactor with an upper surface made of quartz glass, an initial concentration of acetaldehyde was 66 ppm, and dry air (relative humidity: ~33%, total pressure was 760). torr) and at room temperature by irradiating the visible light region with a white window to analyze the photodegradation characteristics of acetaldehyde. Acetaldehyde in the reactor was measured visually using gas chromatography. The results are shown in FIG. 6 .

6 is a graph showing the change in the number of moles of carbon dioxide generated as a result of the photolysis reaction of (a) acetaldehyde and (b) the number of moles of acetaldehyde according to the visible light (white light) irradiation time under a humidity condition of 33%. Looking at the photocatalyst (Fe-TiO ₂ ) prepared in the example, it can be confirmed that the photolysis of acetaldehyde is made by the photocatalytic activity by the irradiation of visible light (white light), and the decomposition efficiency in visible light at the deposition amount of ferrocene is 0.09 wt % You can see this is the biggest one. In addition, as the iron content decreases, it can be seen that the acetaldehyde photodecomposition rate of _{Fe-TiO 2 is increased.}

Evaluation Example 2

_{The photocatalyst (Fe-TiO 2} ) having a deposition amount of ferrocene of 0.13 wt % was analyzed in the same manner as in Evaluation Example 1 in the same manner as in Evaluation Example 1 under dry conditions without humidity and under relative humidity: ~33%, respectively. Acetaldehyde and carbon dioxide in the reactor were periodically measured using gas chromatography. The results are shown in FIGS. 8 and 9 .

7 shows (a) change in moles of acetaldehyde and (b) change in moles of carbon dioxide generated as a result of photolysis of acetaldehyde according to visible light irradiation time when acetaldehyde photolysis experiment was performed under dry conditions and 33% humidity conditions 7, the slopes of the two graphs were similar in the same acetaldehyde concentration section indicated by the dotted line, indicating that the acetaldehyde photolysis activity is maintained similarly in the visible light irradiation regardless of the presence or absence of humidity.

In addition, it can be seen that the carbon dioxide generation increases with the light irradiation time, which is carbon dioxide generated by the complete oxidation of acetaldehyde.

8 shows (a) changes in the number of moles of acetaldehyde and (b) changes in the number of moles of carbon dioxide generated as a result of the photolysis reaction of acetaldehyde according to the visible light irradiation time when repeatedly used in an acetaldehyde photolysis experiment under 33% humidity. It is a graph shown, and it can be seen that high photocatalytic activity is maintained even in repeated photolysis experiments in FIG. 8 .

Overall, in the present invention, TiO ₂ (hereinafter Fe-TiO ₂ ) on which iron oxide is deposited was utilized for photolysis experiments of acetaldehyde, one of representative volatile organic compounds, and Fe-TiO ₂ acetaldehyde photolysis activity according to the content of iron oxide were compared. As a result, when the iron content was as low as about 0.09 wt%, _{the photolysis activity of acetaldehyde of Fe-TiO 2} was the highest, and about 70% of the initial acetaldehyde concentration (~95 mol ppm) was reduced within 20 hours. In addition, in general, the activity of the photocatalyst is greatly affected by humidity, but Fe-TiO ₂ prepared in the present invention showed similar catalytic activity in dry and humid conditions, confirming that the photocatalytic activity is not sensitive to humidity. _{As a result of the nitrogen adsorption experiment of Fe-TiO 2} having various iron contents, it was confirmed that the iron content did not significantly affect the total specific surface area of the photocatalyst. In addition, considering that _{the photocatalytic activity of Fe-TiO 2} is greatly affected by the iron content, it can be seen that the electronic structure of the interface between the _{deposited iron oxide nanoparticles and TiO 2 is more important than the surface structure of the photocatalytic activity.} . In addition, it was confirmed through transmission electron microscopy that the size of the iron oxide particles present on the surface decreased as the iron content decreased, and the photocatalytic activity could be increased when iron oxide particles with a level of 1 to 3 nanometers were deposited. Judging from the analysis results, when the iron oxide nanoparticles of very small size have a content of about 0.09 wt%, Fe-TiO ₂ absorbs light in the visible region to most efficiently separate electron/hole pairs. It reacts with water to form radicals, which can rapidly decompose acetaldehyde. On the other hand, if the target organic material is not completely oxidized but partially oxidized and remains on the surface of the photocatalyst to block the active site, the activity of the photocatalyst decreases, which is pointed out as one of the biggest problems of the photocatalyst. However, Fe-TiO ₂ prepared in the present invention maintained the same catalytic activity even in repeated acetaldehyde photolysis experiments, and thus it was confirmed that there is no problem of catalytic activity degradation.

Manufacture of windows coated with photocatalyst

The photocatalyst prepared by the above-described method was prepared in the form of a composition, and a coating layer was formed (applied) to a thickness of 1 mm on the surface of the window surface of a commonly used window to the interior (applied), and dried.

As a result of measuring the indoor air purification effect with the window installed on the window frame and keeping the window closed, it was confirmed that the photocatalyst was activated in the same way even in the state of the coating layer to realize the expected air purification efficiency.

Manufacture of air purification unit including filter containing photocatalyst and manufacture of window including same

A filter member including a porous nanoweb was formed using an air-laid nonwoven fabric. A photocatalyst was dispersed on the surface of the filter member, and the air purifying unit was formed in the form of a corrugated shape as shown in FIG. 12 . The air permeability of the filter member was formed at 30 CFM by controlling the pleated shape of the filter member to an appropriate line.

The surface of the window is in an open state, and windows and doors separated from the outside and the inside only by the filter member of the air purification unit were installed on the window frame, and the indoor air purification effect was measured while allowing the outside air to flow into the inside. Even when the windows are designed to include a separate air purification unit, the photocatalyst is activated in the same way, and it was confirmed that the expected air purification efficiency for the air entering the room was realized.

As described above, although the embodiments have been described with reference to the limited embodiments and drawings, various modifications and variations are possible from the above description by those skilled in the art. For example, even if the described techniques are performed in an order different from the described method, and/or the described components are combined or combined in a different form from the described method, or replaced or substituted by other components or equivalents Appropriate results can be achieved. Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (10)

In the window provided on the window frame,
It includes a photocatalyst provided on at least one side of the window,
The photocatalyst includes an inorganic oxide and a metal oxide layer derived from an organometallic compound formed on the inorganic oxide, and has photoactivity in a visible light region of 400 nm or more,
The metal oxide layer is to include a ferrocene-derived iron oxide,
The inorganic oxide is to include at least one selected from the group consisting of oxides containing at least one of Ti, Zn, Al and Sn,
The metal oxide layer is to include iron oxide in an amount of 0.001 to 10% by weight compared to the inorganic oxide,
The photocatalyst will have photoactivity in dry conditions of 30% or less of humidity,
Air purification windows containing visible light activated photocatalyst.
According to claim 1,
Further comprising a photocatalytic coating layer provided on at least one surface of the window,
The photocatalyst is dispersedly formed in the photocatalyst coating layer,
Air purification windows containing visible light activated photocatalyst.
According to claim 1,
The windows for air purification are
Further comprising an air purification unit provided on at least one surface of the window,
The air purification unit includes a filter having a plurality of pores, and the photocatalyst is dispersedly formed in the filter,
Air purification windows containing visible light activated photocatalyst.
4. The method of claim 3,
The filter is
A filter member comprising a porous nano-web; and
A support member mounted on the edge of the porous nano-web to support the filter member;
Air purification windows containing visible light activated photocatalyst.
According to claim 1,
The windows for air purification are
Which further comprises a blowing unit for introducing air into the room,
Air purification windows containing visible light activated photocatalyst.
delete delete According to claim 1,
The inorganic oxide does not include an inorganic oxide containing iron,
The metal oxide layer is that the ferrocene deposited on the inorganic oxide is heat-treated,
Air purification windows containing visible light activated photocatalyst.
According to claim 1,
The organometallic compound-derived metal oxide layer is configured to include at least one component of the compound represented by the following Chemical Formula 1,
Air purification windows containing visible light activated photocatalyst.

[Formula 1]
Me _x O _Y H _Z
(Me is at least one metal element in Groups 1 to 3, and X, Y and Z are each selected from 0 to 3, and X and Y are not 0.)
According to claim 1,
The specific surface area of the photocatalyst is 5 (m ² /g) or more, and the average pore size is 50 nm or less,
Air purification windows containing visible light activated photocatalyst.

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