KR102130422B1 - Wall pater comprising visible light active photocatalyst - Google Patents

Abstract

The present invention relates to a wallpaper. Specifically, the present invention relates to a wallpaper containing a visible light active photocatalyst. The wallpaper containing a visible light active photocatalyst according to one aspect of the present invention includes a multilayer structure, and at least one or more layers of multilayers are formed by dispersing the photocatalyst. 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 greater.

Description

Wallpaper containing visible light active photocatalyst {WALL PATER COMPRISING VISIBLE LIGHT ACTIVE PHOTOCATALYST}

The present invention relates to a wallpaper, and more particularly, to a wallpaper including a photocatalyst that can be attached to walls indoors and outdoors.

Wallpaper is a paper that is applied to protect the wall surface and is used for decoration. Laminated wallpaper such as polyvinyl chloride, silk wallpaper, or foam wallpaper is widely used. Recently, not only a simple wall finish function, but also stain resistance of the product surface, There is a great demand for a functional wallpaper capable of removing antibacterial, odor, and odor.

Conventional wallpaper having antibacterial properties is produced by containing conventional organic or inorganic antibacterial agents in raw paper or processed paper, but does not show the effect as much as the amount of the antibacterial agent used, and when using organic antibacterial agents, also has a problem of low persistence.

In order to compensate for this, manufacturers manufacture and manufacture antibacterial agents by coating or impregnating them on the surface or the back of the wallpaper, but there are limitations in diversifying the exterior design of wallpaper with irregularities such as embossing patterns, and also in manufacturing workability and constructability. There are limitations.

Meanwhile, in recent years, as air pollution has emerged, demand for products such as air purifiers has gradually increased, and studies on means that do not occupy volume while purifying air quality have been underway. Among these materials, photocatalysts are emerging.

The 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, by irradiating light (ultraviolet rays) having energy of a band gap or more, a transition of electrons from a valence band to a conduction band occurs, and a hole is formed in the valence band. These electrons and holes diffuse to the surface of the powder, and react with oxygen and moisture to cause a redox reaction or recombine to generate heat. That is, electrons in the conduction band reduce oxygen to generate superoxidion ions, and holes in the valence band oxidize moisture to form hydroxy radicals (OH·). With the strong oxidizing power of hydroxy radicals (OH·) generated by these holes, it is possible to exhibit decomposition, sterilizing power, hydrophilicity, etc. of gaseous or liquid organic substances adsorbed on the surface of the photocatalyst, that is, difficultly decomposing organic substances. In general, titanium dioxide (TiO ₂ ) powder is used as a photocatalyst, and titanium dioxide (TiO ₂ ) has the advantages of being harmless to the human body, having excellent photocatalytic activity, excellent light corrosion resistance, and low price. Titanium dioxide (TiO ₂ ) absorbs and reacts with ultraviolet rays of 388 nm or less to generate electrons (conduction bands) and holes (valence bands). In this case, the ultraviolet rays used as light sources are lamps, incandescent lamps, and mercury lamps. Artificial lighting, light emitting diodes, and the like can be used. The electrons and holes generated in the reaction recombine in 10 ^-12 to 10 ^-9 seconds, but if contaminants or the like adsorb on the surface before recombination, they are decomposed by the electrons and holes. However, to obtain the band gap energy (wavelength of 380nm or more) of titanium dioxide (TiO ₂ ) powder in sunlight, since about 2% of the light can be used, smooth catalytic activity in the visible region (400~800nm), which is the main wavelength of sunlight Have difficulty having That is, in order to respond to visible light, it is essential to effectively reduce the band gap of the photocatalyst and to efficiently separate the electron/hole pairs generated through light absorption, but the efficiency of the visible light-sensitive photocatalyst of titanium dioxide (TiO ₂ ) powder is still It was not reaching the level to be commercialized in the air cleaning field.

The present invention is to solve all of the above-described improvement requirements for the wallpaper material, air pollution in the modern society, supplementation for the insufficient functions of the photocatalyst, etc., the present invention is formed by introducing a doping process of an organometallic compound, An inorganic oxide-based photocatalyst having excellent photocatalytic activity in the visible light region was developed and used for wallpaper.

An embodiment of the present invention is applied by including a part or all of a wallpaper using a photocatalyst activated from newly developed visible light.

An embodiment of the present invention is to provide a wallpaper including an inorganic oxide-based photocatalyst and having a function of purifying ambient air even when exposed to light by having a photolysis function. These technologies are in line with the recent development trend of various facilities to reduce environmental pollution, and solve all the problems of modern catalysts for air purification and photocatalysts that have been difficult to commercialize.

According to an embodiment of the present invention, it is intended to provide a technique for removing harmful substances in ambient air as well as blocking noise in a noise-generating environment by using a wallpaper of the present invention without a separate air purifier.

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.

Wallpaper comprising a visible light active photocatalyst according to an aspect of the present invention includes a multi-layer structure, at least one layer of the multi-layer is a photocatalyst is dispersed, the photocatalyst is an inorganic oxide and an organic metal formed on the inorganic oxide It contains a metal oxide layer derived from a compound and has photoactivity in a visible light region of 400 nm or more.

According to an embodiment, the wallpaper includes a photocatalyst functional layer in which a photocatalyst is dispersed, and a surface treatment layer; Printed layer; Polyvinyl chloride foam layer; And base layer; It may be to include one or more of.

According to one embodiment, the photocatalyst functional layer in which the photocatalyst is dispersed may be formed on the top or bottom surface of the wallpaper.

According to an embodiment, the photocatalyst functional layer in which the photocatalyst is dispersed is 0.1 nm to 1 in a copolymer matrix comprising two or more selected from the group consisting of polyalkylmethacrylate, polyacrylate, vinyl chloride, and vinyl acetate. The photocatalyst particles having a size of µm may be dispersed.

According to an embodiment, the layer in which the photocatalyst is dispersed is 0.1 mm to 0.3 mm thick, and the particles may further include sericite, earstone or both, which are 200 to 400 mesh.

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

According to one embodiment, 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 0.001 to 10 weight compared to the inorganic oxide % Iron oxide, and the photocatalyst may have photoactivity under dry conditions of 30% or less humidity.

According to an embodiment, the photocatalyst may have photoactivity under dry conditions of 30% or less humidity.

According to an embodiment, the inorganic oxide does not include an inorganic oxide containing iron, and the metal oxide layer may be a ferrocene deposited on the inorganic oxide being heat-treated.

According to an embodiment, the photocatalyst may include one or more of the compounds represented by Formula 1 below.

[Formula 1]

Me _x O _Y H _Z

(Me is one or more metal elements of groups 1 to 3, 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 an embodiment of the present invention, a wallpaper including a photocatalyst coating layer is provided, and the wallpaper is pasted on a wall surface, and in addition to the natural function of improving aesthetics, harmful substances in ambient air are reduced by only exposing to visible light. It can work.

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 photodecomposition efficiency in various humidity and temperature regions can be prepared, and a wallpaper applied with the photocatalyst can be provided. have.

The wallpaper proposed in the present invention includes a visible light region and a photocatalyst that is activated even in low humidity environmental conditions, and thus can purify the ambient air even in various exposure environments.

The wallpaper including the visible light-activated photocatalyst proposed in the present invention may be activated by receiving light including a visible light region. Through this, the wallpaper proposed in the present invention can alleviate the fear of air pollution by modern people, and it is possible to purify the surrounding air without having to provide a separate air purification device.

According to an example of the present invention, it is possible to provide a wallpaper that emits anions and far infrared rays that are beneficial to the human body by utilizing ear stones and/or sericite.

According to an example of the present invention, it has a very beneficial effect on human health by having an antibacterial function, an organic substance decomposition function, an odor and odor removal function, which is a function unique to a photocatalyst, beyond a simple wall finishing function. In addition, the functional wallpaper containing the photocatalyst of the present invention increases the specific surface area by maximizing the catalytic activity by adding a titanium dioxide photocatalyst having a particle size of several nanometers (nm), and maintains the original exterior design of the wallpaper in a thin film coating method It has the effect.

1 shows a flowchart of a method for manufacturing a photocatalyst applied to a wallpaper of the present invention according to an embodiment of the present invention.
Figure 2, according to an embodiment of the present invention, illustratively shows the configuration of a TR-CVD reactor used in the manufacturing process of a photocatalyst applied to the wallpaper of the present invention.
Figure 3, according to an embodiment of the present invention, illustratively shows the manufacturing process of the photocatalyst applied to the present invention.
Figure 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.
Figure 6 shows the results of the evaluation of the photocatalytic performance of the photocatalyst prepared according to the embodiment of the present invention.
Figure 7 shows the evaluation results of the photolysis performance according to the humidity of the photocatalyst prepared according to an embodiment of the present invention.
Figure 8 shows the results of the stability evaluation of the photolysis performance according to repeated photolysis experiments of the photocatalyst prepared according to the 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. The examples described below are not intended to be limiting with respect to the embodiments, and should be understood to include all modifications, equivalents, or substitutes thereof.

The terms used in the examples are only used to describe specific examples, and are not intended to limit the examples. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “include” or “have” are intended to indicate that there are features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and one or more other features. It should be understood that the existence or addition possibilities of fields or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance.

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

In addition, in the description with reference to the accompanying drawings, the same components are given the same reference numerals regardless of the reference numerals, and redundant descriptions thereof will be omitted. In describing the embodiments, when it is determined that detailed descriptions of related well-known technologies may unnecessarily obscure the subject matter of the embodiments, detailed descriptions thereof will be omitted.

In addition, terms used in the present specification are terms used to appropriately represent a preferred embodiment of the present invention, which may vary depending on a user, an operator's intention, or a custom in the field to which the present invention pertains. Therefore, definitions of these terms should be made based on the contents throughout the present specification. The same reference numerals in each drawing denote the same members.

Throughout the specification, when one member is positioned “on” another member, this includes not only the case where one member abuts another member, but also the case where another member exists between the two members.

Throughout the specification, when a part “includes” a certain component, it means that the other component may be further included instead of excluding the other component.

Hereinafter, the wallpaper containing 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.

The present invention may be related to a wallpaper capable of performing a function of purifying the ambient air only by actually installing and exposing the photocatalyst particles to the coating layer of the wallpaper. In addition, the photocatalyst applied to the wallpaper of the present invention can be sufficiently activated even if the wavelength of the ultraviolet region is not irradiated and exposed to light in the visible region, unlike conventional photocatalysts. Therefore, it is possible to purify the air in the surrounding space with high efficiency without a special driving device even by being exposed to sunlight in the outdoors or indoors.

The present inventor has confirmed that such an effect can be realized through a photocatalyst comprising a metal oxide layer formed by heat-treating an organometallic compound, and develops and proposes a wallpaper capable of maximizing the properties of the photocatalyst. .

The present invention is expected to have a function of purifying ambient air and releasing beneficial components to the human body in addition to the wall finishing function of a general wallpaper.

Wallpaper comprising a visible light active photocatalyst according to an aspect of the present invention includes a multi-layer structure, at least one layer of the multi-layer is a photocatalyst is dispersed, the photocatalyst is an inorganic oxide and an organic metal formed on the inorganic oxide It contains a metal oxide layer derived from a compound and has photoactivity in a visible light region of 400 nm or more.

Since the photocatalyst is dispersed and contained in an active state in a very small size, it can decompose contaminants with strong oxidizing power. Particularly, it receives light and generates an electric potential to show the characteristics of the photocatalyst by the potential difference. It is more micronized than the conventional micro-level titanium dioxide photocatalyst, and thus has better oxidizing power, and has excellent persistence.

The photocatalyst can be activated by a radical action, and is capable of oxidizing and decomposing many types of contaminants without being limited by the type because it has an oxidizing power more than twice that of conventional oxidizing agents such as ozone and chlorine.

As an example, the photocatalyst can be imparted with the above-described oxidative decomposition property and superhydrophilicity by being included in any one layer of a wallpaper made of a multi-layer structure such as a conventional polyvinyl chloride-based laminated wallpaper or a laminated wallpaper.

As an example, since the photocatalyst is contained in a state of ultra-fine particles having a very high specific surface area, there is no need to change the process of manufacturing a conventional wallpaper separately, the manufacturing workability is excellent, and the construction workability is not different. In addition, since it is contained in the ultra-fine state of the nano level below the micro level, there is also an effect that the embossed pattern can be manufactured as it is without changing the conventional wallpaper design.

According to an embodiment, the wallpaper includes a photocatalyst functional layer in which a photocatalyst is dispersed, and a surface treatment layer; Printed layer; Polyvinyl chloride foam layer; And base layer; It may be to include one or more of.

As an example, the printing layer 30 is printed by printing a pattern on the polyvinyl chloride foam layer 20 by gravure printing, offset-printing, or screen printing. It may be to form.

Also, the surface treatment layer 40 may be formed by gravure coating or screen coating the acrylic copolymer composition.

The polyvinyl chloride foam layer is a polyvinyl chloride resin having a polymerization degree of 500 to 1500 in 100 parts by weight of a) a primary plasticizer dioctyl phthalate 65 to 75 parts by weight; b) 1 to 5 parts by weight of azodicarbonamide as a blowing agent; c) 1 to 4 parts by weight of a zinc compound that is a foaming accelerator; d) 0.1 to 3 parts by weight of a barium-zinc compound that is a foam stabilizer; e) 6 to 8 parts by weight of titanium dioxide as a pigment; And f) a liquid composition containing 50 to 60 parts by weight of calcium bicarbonate as a filler, coated with a thickness of 0.3 to 0.5 mm, heated to gel, and foamed.

The photocatalyst may be contained in any one layer of various polyvinyl chloride-based foamed laminated wallpaper, or laminated wallpaper. The content of the photocatalyst is preferably 1 to 10 parts by weight based on 100 parts by weight of the solid content of each layer. If the content is less than 1 part by weight, the photocatalytic effect is insufficient, and if it exceeds 10 parts by weight, the effect is saturated and the cost increases.

According to one embodiment, the photocatalyst functional layer in which the photocatalyst is dispersed may be formed on the top or bottom surface of the wallpaper.

When formed on the top surface, the photocatalyst of the photocatalytic functional layer is in direct contact with sunlight, thereby promoting photocatalytic activation. When located on the lowest surface, it is possible to minimize a decrease in aesthetics that occurs as the photocatalyst is applied.

As an example, the wallpaper may be manufactured through an embossing process, and the embossing process is performed by heating the laminated foam wallpaper at 180 to 220° C. for 20 to 40 seconds and then embossing and cooling to complete the final product. Can.

According to an embodiment, the photocatalyst functional layer in which the photocatalyst is dispersed is 0.1 nm to 1 in a copolymer matrix comprising two or more selected from the group consisting of polyalkylmethacrylate, polyacrylate, vinyl chloride, and vinyl acetate. The photocatalyst particles having a size of µm may be dispersed.

According to an embodiment, the layer in which the photocatalyst is dispersed is 0.1 mm to 0.3 mm thick, and the particles may further include sericite, earstone or both, which are 200 to 400 mesh.

In the above, the yangyangseok particles may be 100 to 600 mesh, preferably 200 to 400 mesh, more preferably 325 mesh to 400 mesh, and the mica may be 200 to 400 mesh, preferably 325 mesh to 400 mesh Can.

In general, Guiyangki (Kiyoseki) is a new material that emits a large amount of negative ions (24,140ea/cc) on the planet and emits the best far infrared rays (96%) at room temperature of 25℃. It is present in the mine formed by the action and is a mysterious substance condensing the energy of the natural world. It is the only natural stone in the world that is produced only in Gunma Prefecture, Japan. As a feature, it shows a high surfactant effect (101% increase), increases a large amount of alpha waves among brain waves, increases blood flow by 4.9%, and decreases blood flow rate by 7.2%.

The yangyangseok is used to add a function to emit beneficial current, anion and far infrared rays to the human body, and uses crushed stone powder with a particle size of 100 to 600 mesh, preferably 200 to 400 mesh, more preferably 325 Mesh is suitable. When using less than 100 mesh of precious stone powder, mixing with natural adhesive and ocher is not smooth due to the large particle of precious stone powder, and when it is applied to the wallpaper and dried, the texture becomes rough and the risk of injury increases. Because it is easy to deviate. In addition, more than 600 mesh precious stone powder is increased because it requires an additional grinding step, it is preferable not to use because of its low efficiency compared to the increased cost.

The sericite (Ilite) is a cationic floating particle in water and electrical neutralization to cause precipitation, which is excellent in water purification, self-functioning function, moisturizing effect and high activity, in addition to the unique properties of high to 5 to 20 micro wavelengths at room temperature It is characterized by radiating far-infrared rays of over 90% and is a mineral with excellent adsorption power by emitting strong anions.

In addition, it is a substance that emits far-infrared rays that promote blood circulation in the human body and activate cell activity. It has the ability to adsorb various harmful substances and can control humidity.

Since sericite has strong binding properties with wood pulp stock, it can be used by mixing it with stock and yangyangseok to add characteristics such as acidity to the wallpaper. After collecting impurities, crushed and filtered to remove impurities and to have a particle size of 325 mesh, and 20 to 30% by weight of crushed silk with selected pure 325 mesh is used. The reason for using such a weight ratio is that the composition mixed with the mica and yangyangseok has viscous properties suitable for mixing with the pulp of the wood pulp, while retaining the natural ore properties of the mica.

The photocatalyst applied to an example of the present invention is activated only in the ultraviolet region, thereby improving the problem of the conventional photocatalyst, which is difficult to commercialize, and is sufficiently activated in the visible region 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.

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

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

According to one embodiment, 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 0.001 to 10 weight compared to the inorganic oxide % Iron oxide, and the photocatalyst may have photoactivity under dry conditions of 30% or less humidity.

According to one embodiment, the photocatalyst, inorganic oxide; And a metal oxide layer formed on the inorganic oxide. It may include.

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

The inorganic oxide is an inorganic semiconductor compound that absorbs light energy and exhibits catalytic activity. 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, it may be 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, semiconductor compounds such as CdS, GaP, InP, GaAs, and 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, powder, rod, wire, needle, and fiber, and the size of the inorganic oxide may be 1 nm to 500 μm.

The inorganic oxide may include at least one selected from the group consisting of beads, powder, rod, wire, needle, and fiber, and the size of the inorganic oxide is 1 nm or more; 10 nm or more; 30 nm to 500 μm; 30 nm to 100 μm; Or 30 nm to 1 μm. The size may mean diameter, thickness, length, etc., depending on the shape.

According to an embodiment, the inorganic oxide does not include an inorganic oxide containing iron, and the metal oxide layer may be a ferrocene deposited on the inorganic oxide being heat-treated.

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 ferrocene, and may include iron oxide converted from ferrocene by the thermal decomposition process. 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 organic metal oxide may be, for example, iron oxide derived from at least one of ferrocene and ferrocene derivatives. The ferrocene derivatives include 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' -In the group consisting of 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. When included in the above range, photocatalytic activity in the visible light region may be increased to improve photolysis efficiency. In addition, although the absorption of the visible region may increase when the content of the metal increases, it is preferable to include the content of the metal within the above range, and more preferably, since the decrease in the photocatalytic activity may occur due to the increase in the content of the metal. The metal is iron, and the content of the iron may be 0.01 to 5% by weight.

As an example, the metal oxide layer derived from the organometallic compound may be 0.01 nm or more; 0.1 nm or more; 10 nm or more; Or it may have a thickness of 1 nm to 100 nm. When included in the thickness range, the porosity of the photocatalyst can be prevented due to an increase in the thickness of the coating layer, and the amount of adsorption of moisture, OH-ions, decomposition targets, etc. on the surface can be increased to improve photodegradation performance. In addition, the metal oxide layer derived from the organometallic compound, 0.01 nm or more; 0.1 nm or more; 10 nm or more; Or it may include ferrocene-derived iron oxide having a size of 1 nm to 100 nm. The size may mean length, diameter, thickness, and the like depending on the shape.

According to one embodiment, the inorganic oxide does not include an inorganic oxide containing iron, and the iron oxide layer may be a ferrocene deposited on the inorganic oxide being heat-treated.

The photocatalyst may include one or more of the compounds represented by Formula 1 below.

[Formula 1]

Me _x O _Y H _Z

Here, Me is at least one of the 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, a photocatalyst that responds to visible light by absorbing light in the visible light region and introducing iron oxide (Fe _x O _y H _z ), a stable and inexpensive semiconducting material, in the form of nano-sized particles to the TiO ₂ surface Can form.

According to an embodiment of the present invention, in the photocatalyst, a wavelength region exhibiting a photoreaction by absorbing light may be extended from ultraviolet light to visible light. The photocatalyst can exhibit much better photocatalytic activity than conventional photocatalysts, especially in the visible light region of 400 nm or more. In addition, the photocatalytic reactivity capable of adsorption and decomposition of the decomposition target on the surface is improved to have photocatalytic activity in various humidity regions, and can exhibit excellent photocatalytic activity even in dry conditions of 30% or less humidity.

According to one example, the photocatalyst particles, 5 (m ² / g) or more; 5 (m ² /g) to 1000 (m ² /g); Or it has a specific surface area of 5 (m ² /g) to 100 (m ² /g), and the average pore size may be 50 nm or less. By introducing a metal oxide derived from an organometallic compound onto the surface of the inorganic oxide, the amount of adsorption target to be decomposed increases on the surface of the photocatalyst, and the photocatalytic reactivity is increased to improve the efficiency of the photocatalyst.

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 for treatment of 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 materials, and may exhibit photoactivity by light energy including various light rays such as halogen lamps, xenon lamps, sunlight, and light emitting diodes. More specifically, as the gas, VOCs (volatile organic compounds) such as acidic, basic gas, acetaldehyde, ketones, hydrocarbons of aromatic hydrocarbons and aliphatic hydrocarbons (Paraffin-based and Olefin-based), 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 , Olefin, and the like. Examples of the liquid include formaldehyde, acetaldehyde, benzene, toluene, methyl ethyl ethyl ketone (MEK), trichloroethylene, disinfectant, gasoline, diesel, oil, alcohol, Phenol, dye, and the like, and the solid may be a transition metal, a precious metal such as Pt, Pd, ions and/or particles such as Hg, Cr, nanoparticles of 100 nm or less, but is not limited thereto.

1 shows a flowchart of a method for manufacturing a photocatalyst according to the present invention, according to an embodiment of the present invention. According to an example, after preparing a photocatalyst in the manner shown in FIG. 1, in the process of manufacturing and dispersing the photocatalyst described above, a wallpaper formed with a coating layer comprising a photocatalyst according to an embodiment of the present invention is mixed. Can be produced.

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

The manufacturing method of the photocatalyst comprises: preparing an inorganic oxide; Forming a metal oxide layer on the inorganic oxide; And forming a metal oxide layer derived from an organic metal oxide by heat treatment after the step of forming the metal oxide layer.

The preparing of the inorganic oxide is a step of preparing an inorganic oxide dispersion or coating an inorganic oxide on a substrate, wherein the dispersion is an aqueous solvent, an oily solvent, or a mixture of the two, 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 step of forming the organic metal oxide layer, an organic metal oxide film may be formed using a wet coating method, a sputtering method, or a vapor deposition method. As an example, the organic metal oxide film may be a ferrocene film. Preferably, a deposition method such as atomic layer deposition (ALD) or temperature-regulated chemical vapor deposition (CVD) is used, and more preferably, TR-CVD (temperature-regulated chemical vapor deposition) is used. A ferrocene layer can be formed. As an example, when the 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 manufacturing process of the photocatalyst can be simplified and the photocatalyst can be efficiently provided.

The step of forming the organic metal oxide layer is performed at room temperature to 120°C, preferably 40°C to 100°C; More preferably it can be carried out at 60 ℃ to 100 ℃. That is, it can be carried out at 60 ℃ to 100 ℃ in order to induce the deposition by the vaporization process of the organic metal oxide layer when applying TR-CVD.

The step of forming the organic metal oxide layer is performed 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 includes 0.01% to 20% by weight of ferrocene compared to the inorganic oxide, and may form the ferrocene layer.

The step of forming the metal oxide layer derived from the organometallic oxide may be partially or completely oxidized with a metal oxide through heat treatment of the organometallic oxide layer, and impurities such as carbon residues may be removed.

The forming of the metal oxide layer derived from the organic metal oxide may include 50°C to 900°C; Alternatively 100°C to 800°C; Heat treatment may be performed at two or more stages at a temperature.

For example, the step of forming the metal oxide layer derived from the organic metal oxide includes 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, and each step Heat treatment may be performed at different temperatures. Each of the above steps is performed for 1 minute to 20 hours, respectively, and air, 20% or more; It can be carried out in an air or inert gas atmosphere containing at least 40% oxygen.

That is, the first heat treatment step may be an annealing process for depositing a metal oxide that is converted to a metal oxide by reaction of an 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 process to improve the activity and performance of the photocatalyst by removing impurities such as carbides.

Hereinafter, the present invention will be described in more detail by examples and comparative examples.

Preparation of photocatalyst and evaluation of properties

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

However, the following examples were introduced to demonstrate the manufacturing process of the photocatalyst of the present invention and the effect realized therefrom, and are merely examples of selecting ferrocene as the organic metal oxide, and the contents of the present invention are limited to the following examples It does not work.

Example 1

A photocatalyst (Fe-TiO ₂ ) in which nano-sized iron oxide particles are deposited on TiO ₂ is prepared using the TR-CVD (temperature-controlled chemical vapor deposition) reactor of FIG. ₂ and utilizing the temperature-controlled chemical vapor deposition method shown in FIG. 3. Did. More specifically, 0.02 g of ferrocene, a precursor of iron, is placed in a container 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 in the center inside the reactor, the reactor is sealed with polyimide tape. The temperature of the reactor was carried out by a TR-CVD vaporization process at 60° C. for 2 hours, and then a ferrocene deposition process was performed, and 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 nanostructured photocatalyst was prepared in the same manner as in Example 1 except that 0.05 g of the iron precursor Ferrocene was applied. The iron content deposited on TiO ₂ under the conditions is about 0.13 wt%.

Example 3

An iron oxide-TiO ₂ hybrid nanostructured photocatalyst was prepared in the same manner as in Example 1, except that 0.1 g of the iron precursor Ferrocene was applied. The iron content deposited on TiO ₂ under the conditions is about 0.65 wt%.

Example 4

An iron oxide-TiO ₂ hybrid nanostructured photocatalyst 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 ) is compared to a TiO ₂ photocatalyst coated with a general iron oxide, and the transparency and color are shown in FIG. 4. 4, the photocatalyst (Fe-TiO ₂ ) coated with ferrocene-derived iron oxide according to the present invention is more transparent and lighter 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.

The 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 decreased, the size of the iron oxide particles deposited on the Fe-TiO ₂ surface decreased.

The specific surface area (BET) and BJH average pore size through the nitrogen adsorption analysis of the prepared photocatalyst (Fe-TiO ₂ ) are measured and are shown in Table 1.

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

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

Evaluation Example 1

Put the photocatalyst (Fe-TiO ₂ ) of Example 1 in a volume 5.3 L reactor composed of quartz glass on the top surface, acetaldehyde initial concentration 66 ppm, dry air (relative humidity: ~33%, total pressure 760 torr) and the photodegradation properties of acetaldehyde were analyzed by irradiating the visible light region with a white wallpaper at room temperature. Acetaldehyde in the reactor was measured by gas chromatography. The results are shown in FIG. 6.

FIG. 6 is a graph showing (a) acetaldehyde mole number change over time of visible light (white light) irradiation at 33% humidity condition, and (b) carbon dioxide mole number change as a result of photodecomposition reaction of acetaldehyde. Looking at it, the photocatalyst (Fe-TiO ₂ ) prepared in Example can be confirmed that photodecomposition of acetaldehyde is performed by photocatalytic activity by visible light (white light) irradiation, and the ferrocene deposition amount is 0.09 wt% and decomposition efficiency in visible light You can see this is the biggest. In addition, it can be seen that the smaller the iron content, the faster the photodecomposition rate of acetaldehyde of Fe-TiO ₂ .

Evaluation Example 2

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

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

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

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

Overall, the present invention, TiO ₂ (hereinafter Fe-TiO ₂ ) on which iron oxide is deposited, was utilized for photodegradation experiments of acetaldehyde, which is one of the representative volatile organic compounds, and acetaldehyde photodegradation activity of Fe-TiO ₂ according to the content of iron oxide Compared. As a result, when the iron content was as low as about 0.09 wt%, the photodegradation activity of acetaldehyde of Fe-TiO ₂ was the highest, and about 70% of the initial acetaldehyde concentration (~95 mol ppm) decreased 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 shows similar catalytic activity under dry conditions and humidity conditions, confirming that the photocatalytic activity is not sensitive to humidity. As a result of nitrogen adsorption experiments 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 was greatly affected by the iron content, it can be seen that the photocatalytic activity is more important in the electronic structure of the interface between the deposited iron oxide nanoparticles and TiO ₂ than the surface structure. . In addition, it was confirmed through a transmission electron microscope that the smaller the iron content, the smaller the size of the iron oxide particles present on the surface. When 1~3 nanometer-level iron oxide particles were deposited, the photocatalytic activity may be increased. Based on the results of the analysis, Fe-TiO ₂ absorbs light in the visible region when the iron oxide nanoparticles of a very small size have a content of about 0.09 wt%, and the electron/hole pairs are most efficiently separated, and oxygen/ It can react with water to form radicals, which can rapidly break down acetaldehyde. On the other hand, if the target organic material is not completely oxidized and partially oxidized and remains on the surface of the photocatalyst to block the active site, the activity of the photocatalyst decreases, which has been pointed out as one of the biggest problems of the photocatalyst. However, the 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 was no problem of catalytic activity degradation.

Anionic and air purification performance test of photocatalyst wallpaper

The photocatalyst prepared according to the above-described method, the mica and ear stones were included in the uppermost layer of the wallpaper including the multilayer structure of the present invention, and a wallpaper according to an embodiment of the present invention was prepared.

Thereafter, anion emission was measured by using a charge particle measuring device as a test method of KICM-FIR-1042. At this time, the measurement was performed under the conditions of temperature 21°C, humidity 40% and atmospheric anion water 68/cc, and anions emitted from the measurement object were measured as the number of ions per unit volume.

In addition, the ability to irradiate visible light and decompose harmful substances indoors was tested as described above.

Through the above test, it was confirmed that the silkworm and yangyangseok equipped with a photocatalyst on the wallpaper showed the intrinsic effect to generate anions, and the photocatalyst was also confirmed to purify harmful substances by receiving light in accordance with the natural function.

As described above, although the embodiments have been described by a limited embodiment and drawings, those skilled in the art can make various modifications and variations from the above description. For example, even if the described techniques are performed in a different order than the described method, and/or the described components are combined or combined in a different form from the described method, or replaced or replaced by another component or equivalent 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)

Including a multi-layer structure,
At least one layer of the multilayer is a photocatalyst dispersed,
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 includes ferrocene-derived iron oxide,
The metal oxide layer comprises 0.001 to 10% by weight of iron oxide compared to the inorganic oxide,
Wallpaper containing visible light active photocatalyst.
According to claim 1,
The wallpaper,
Includes a photocatalyst functional layer formed by dispersing a photocatalyst,
Surface treatment layer;
Printed layer;
Polyvinyl chloride foam layer; And
Base layer; It further comprises one or more of the
Wallpaper containing visible light active photocatalyst.
According to claim 2,
The photocatalyst functional layer in which the photocatalyst is dispersed is formed,
It is formed on the top or bottom surface of the wallpaper,
Wallpaper containing visible light active photocatalyst.
According to claim 2,
The photocatalyst functional layer in which the photocatalyst is dispersed is formed,
The photocatalyst particles having a size of 0.1 nm to 1 μm are dispersed in a copolymer matrix including two or more selected from the group consisting of polyalkyl methacrylate, polyacrylate, vinyl chloride and vinyl acetate,
Wallpaper containing visible light active photocatalyst.
According to claim 1,
The layer in which the photocatalyst is dispersed is 0.1 mm to 0.3 mm thick,
Wherein the particles further comprise sericite, earstone or both, which are between 200 and 400 mesh,
Wallpaper containing visible light active photocatalyst.
delete According to claim 1,
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 photocatalyst is to have photoactivity under dry conditions of humidity of 30% or less,
Wallpaper containing visible light active photocatalyst.
According to claim 1,
The inorganic oxide does not contain an inorganic oxide containing iron,
In the metal oxide layer, ferrocene deposited on the inorganic oxide is heat-treated,
Wallpaper containing visible light active photocatalyst.
According to claim 1,
The photocatalyst is to include at least one of the compounds represented by the following formula (1),
Wallpaper containing visible light active photocatalyst.
[Formula 1]
Me _x O _Y H _Z
(Me is one or more metal elements of groups 1 to 3, 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,
Wallpaper containing visible light active photocatalyst.

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