KR102084019B1 - Block for earthwall comprising visible light active photocatalyst - Google Patents

Abstract

The present invention relates to a block, which is used for constructing a retaining wall. The retaining wall includes visible light active photocatalyst. According to one aspect of the present invention, the retaining wall including the visible light active photocatalyst is formed such that the photocatalyst is dispersed in a main material including one or more selected in a group comprising cement, wood, sand and aggregates. The photocatalyst includes inorganic oxide and a metal oxide layer derived from an organometallic compound formed on the inorganic oxide, and has photoactivity in a visible light area of 400 nm or more.

Description

Retaining wall block containing visible light active photocatalyst {BLOCK FOR EARTHWALL COMPRISING VISIBLE LIGHT ACTIVE PHOTOCATALYST}

The present invention relates to a retaining wall, and more particularly, to a retaining wall having an air purification function including a photocatalyst.

In general, the retaining wall structure is designed to prevent the collapse of soil or cuts in roads, rivers, and cutouts. It is constructed of artificial structures such as bricks, concrete, concrete panels, and concrete blocks. Retaining wall structures made of concrete are widely used in consideration of their properties.

However, the retaining wall as described above gives a sense of discomfort due to the color and uniform shape peculiar to the concrete, it is a case that spoils the natural landscape. In particular, when concrete retaining walls are installed on slopes, cutouts, and staircase retaining walls of common living complexes and public facilities such as apartment complexes, parks, museums, and exhibition halls, there is a problem that is contrary to the taste of modern people pursuing a natural environment. Is occurring.

In addition, generally used concrete retaining wall is eluted with moisture, concrete phenomena appear whitening and harmful substances are generated. This not only causes environmental pollution but also points out problems that appear very messy.

In order to overcome this, various coating materials have been disclosed, but since the life span is short, or because the composition is a coating material containing non-friendly compositions such as lime or cement, it is very undesirable as an outdoor coating material. have.

On the other hand, in modern society, not only fine dust but also various chemicals exist in the air, which is emerging as a whole human concern to be addressed by the deterioration of health caused by air pollution. In connection with such air pollution, air purifiers have emerged as an essential item for modern people. However, since air purifiers require the introduction of additional equipment to purify the air, research has recently been conducted on how to add a function to purify the air itself in structures that are used indoors and outdoors.

As such, there is a photocatalyst technology as a technology introduced to solve indoor and outdoor air pollution using a structure existing around it. 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 irradiates light (ultraviolet rays) having energy of a band gap or more to cause a transition of electrons from a valence band to a conduction band, and a hole is formed in the valence band. These electrons and holes diffuse to the surface of the powder and come into contact with oxygen and moisture to cause a redox reaction or to recombine to generate heat. That is, electrons in the conduction band reduce oxygen to generate superoxane ions, and holes in the valence band oxidize moisture to form hydroxy radicals (OH ·). It is possible to exhibit decomposition, sterilization, hydrophilicity, etc. of gaseous or liquid organic substances adsorbed on the surface of the photocatalyst, ie, hardly dissolving organic substances, by the strong oxidizing power of hydroxy radicals (OH ·) generated by such holes. Generally, titanium dioxide (TiO ₂ ) powder is used as a photocatalyst, and titanium dioxide (TiO ₂ ) is harmless to humans, has excellent photocatalytic activity, has excellent corrosion resistance and low cost. Titanium dioxide (TiO ₂ ) absorbs and reacts with ultraviolet rays of 388 nm or less to generate electrons (conductor bands) and holes (valence bands). 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 are decomposed by the electrons and holes if contaminants or the like adsorb to the surface before recombination. However, the bandgap energy of titanium dioxide (TiO ₂ ) powder (wavelength of 380nm or more) is obtained from sunlight, and since 2% of the light is available, the catalyst activity is smooth in the visible light region (400-800nm), which is the main wavelength of sunlight. Have difficulty with 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 far below the level to be commercialized in the air clean field.

The present invention is to solve all of the above-described demands for improving the characteristics of the retaining wall, and to compensate for air pollution in modern society, lack of photocatalysts, and the like. Inorganic oxide-based photocatalysts having excellent photocatalytic activity in the light ray region have been developed and used for retaining walls.

The present invention is applied to the main material forming the retaining wall by using a photocatalyst activated by newly developed visible light, or applied by forming a coating layer on a part of the retaining wall. It is intended to purify.

An embodiment of the present invention is to provide a retaining wall including an inorganic oxide-based photocatalyst and having a function of purifying ambient air even when exposed to light by having a photolysis function. This technology is in line with the development trend of various facilities to reduce environmental pollution in recent years, and solves all the problems of the modern man's desire for air purification and the photocatalyst which was difficult to be commercialized.

However, the problem to be solved by the present invention is 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.

According to one aspect of the present invention, a retaining wall block including a visible light active photocatalyst is a block used to construct a retaining wall, and the photocatalyst is added to a main material including at least one selected from the group consisting of cement, wood, sand and aggregate. The photocatalyst is formed by dispersing an inorganic oxide and a metal oxide layer derived from an organometallic compound formed on the inorganic oxide and having photoactivity in a visible light region of 400 nm or more.

According to one embodiment, the retaining wall block may be obtained by curing the agitated mortar by mixing water and a photocatalyst in the main material.

According to one embodiment, with respect to 100 parts by weight of the main material, 1 to 5 parts by weight of the pigment; 0.1 to 3 parts by weight of a coarse agent; 0.5 to 5 parts by weight of anti-whitening agent; And 0.5 to 5 parts by weight of a reducing agent; further comprising an additive including at least one selected from the group consisting of, and the photocatalyst may be included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the main material.

According to another aspect of the present invention, a retaining wall including a visible light active photocatalyst is a block used to construct the retaining wall, and is formed on a substrate formed of a main material including at least one selected from the group consisting of cement, wood, sand and aggregate. A coating material coating layer including a photocatalyst is formed on the photocatalyst, and the photocatalyst may include an inorganic oxide and a metal oxide layer derived from an organometallic compound formed on the inorganic oxide, and may have photoactivity in a visible light region of 400 nm or more.

According to one embodiment, the coating material coating layer may further include one or more selected from the group consisting of ocher, illite, acrylic, magnesium oxide and magnesium chloride.

According to one embodiment, the coating material coating layer may be formed to a thickness of 1 mm to 10 mm.

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

According to one embodiment, the inorganic oxide, at least one selected from the group consisting of an oxide containing at least one of Ti, Zn, Al and Sn, the metal oxide layer is 0.001 to 10% by weight compared to the inorganic oxide It is to include iron oxide of%, the photocatalyst, may have a photoactivity under dry conditions of 30% or less humidity.

According to an embodiment, the inorganic oxide may 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 Formula 1 below.

[Formula 1]

Me _x O _Y H _Z

(Me is at least one metal element 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 of the present invention, a retaining wall including a photocatalyst coating layer is provided, and the retaining wall has an effect of preventing harmful substances in ambient air by only exposing to visible light in addition to its inherent function of preventing collapse. have.

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 may be prepared, and a retaining wall to which the photocatalyst is applied may be provided. have.

The retaining wall proposed in the present invention includes a photocatalyst that is activated even in a visible light region and low humidity environment conditions, and thus can purify the ambient air in various climatic conditions and natural light exposure environment.

The retaining wall including the visible light active 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 retaining wall proposed by the present invention can alleviate the fear of air pollution by modern people, and can be applied to various environments by being able to purify the ambient air without having to provide a separate air purifier.

Figure 1 shows a flow chart of a method for producing a photocatalyst applied to the retaining wall of the present invention, according to an embodiment of the present invention.
FIG. 2 exemplarily shows a configuration of a TR-CVD reactor used in the manufacturing process of the photocatalyst applied to the retaining wall of the present invention according to an embodiment of the present invention.
3 exemplarily shows a process for producing a photocatalyst applied to the retaining wall of the present invention according to an embodiment of the present invention.
4 shows an image of a photocatalyst applied to the present invention manufactured 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 evaluation results of the photolysis performance of the photocatalyst prepared according to the embodiment of the present invention.
7 shows evaluation results of photodegradation performance according to humidity of a photocatalyst prepared according to an embodiment of the present invention.
Figure 8 shows the results of the stability evaluation of photodegradation performance according to the repeated photolysis experiment of the photocatalyst prepared according to the embodiment of the present invention.

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

Various changes may be made to the embodiments described below. The examples described below are not intended to be limited to the embodiments and should be understood to include all modifications, equivalents, and substitutes for them.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of examples. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present disclosure does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

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

In addition, terms used in the present specification are terms used to properly express preferred embodiments of the present invention, which may vary according to a user, an operator's intention, or customs in the field to which the present invention belongs. Therefore, the definitions of the terms should be made based on the contents throughout the specification. Like reference numerals in the drawings denote like elements.

Throughout the specification, when a member is located "on" another member, this includes not only when one member is in contact with another member but also when another member is present between the two members.

Throughout the specification, when a part is said to "include" a certain component, it means that it may further include other components, not to exclude other components.

Hereinafter, a retaining wall block including the photocatalyst of the present invention will be described in detail with reference to embodiments and drawings. However, the present invention is not limited to these embodiments and drawings.

The present invention may be related to a retaining wall that includes a photocatalyst particle in a retaining wall block and is actually installed and performs a function of purifying ambient air only by being exposed to light. Furthermore, unlike the conventional photocatalysts, the photocatalyst applied to the retaining wall block of the present invention can be sufficiently activated even if the wavelength of the ultraviolet region is not irradiated and is exposed to light in the visible region. Therefore, the exposure to sunlight in the outdoors or indoors alone can purify the air in the surrounding space with high efficiency without any special driving device.

The present inventors have confirmed that the present invention can be realized through a photocatalyst including a metal oxide layer formed by heat-treating an organometallic compound, and developed and proposed a retaining wall block capable of maximizing the characteristics of the photocatalyst. It is.

In addition, the retaining wall block proposed in the embodiment of the present invention can provide a retaining wall block having a texture similar to natural stone without being uniform. In addition, the retaining wall provided in the embodiment of the present invention also has a toxic gas adsorption and anti-whitening effect.

The photocatalyst applied to an example of the present invention improves the problem of the conventional photocatalyst, which is activated only in the ultraviolet region and is difficult to commercialize, and is sufficiently activated in the visible 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. At this time, it is referred to as a photocatalyst including the inorganic oxide and the metal oxide layer. The photocatalyst may or may not be in the form of particles. Unlike the conventional photocatalysts, the photocatalyst has active photoactivity by reacting with a wavelength in the visible light region of 400 nm or more. This may be an effect implemented in a metal oxide layer derived from an organometallic compound.

The photocatalyst particles may be present on an outer surface exposed to light of the retaining wall.

According to one aspect of the invention, the retaining wall comprising a visible light active photocatalyst is a block used to build the retaining wall, the photocatalyst is formed dispersed in the main material comprising at least one selected from the group consisting of cement, wood, sand and aggregate 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.

According to one embodiment, the retaining wall block may be obtained by curing the agitated mortar by mixing water and a photocatalyst in the main material.

As an example, the retaining wall block is preferably manufactured to have a natural stone texture and shape, so that it is easy to build, and a mixture of cement, wood, sand, and aggregates as a main component is mixed with water and an additive in a raw material mixture to stir mortar. It can be secured by curing.

As an example, the composition of the mortar is 32 to 55 parts by weight of water with respect to 100 parts by weight of the cement in a raw material mixture of 13 to 25% by weight of cement, 20 to 45% by weight of sand, and 30 to 67% by weight of aggregate. Additives 2.5 to 13 parts by weight may be configured by mixing and stirring.

The aggregate is used to crush the general gravel aggregate, in order to increase the texture effect of natural stone can be used 20 ~ 50wt% recycled aggregate or natural aggregate relative to the total weight of the aggregate. At this time, the recycled aggregate may be used steel slag, crushed glass, crushed plastic, crushed ceramics, etc., natural stone aggregate may be used dolomite, serpentine, color aggregate and aluminum silicate minerals.

According to one embodiment, with respect to 100 parts by weight of the main material, 1 to 5 parts by weight of the pigment; 0.1 to 3 parts by weight of a coarse agent; 0.5 to 5 parts by weight of anti-whitening agent; And 0.5 to 5 parts by weight of a reducing agent; further comprising an additive including at least one selected from the group consisting of, and the photocatalyst may be included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the main material.

The pigment is a subsidiary material added to obtain a color desired by a user, and may selectively use at least one or more kinds of pigments capable of obtaining a selected color.

The crude steel is a raw material for promoting hardening, the anti-whitening agent is a raw material for preventing the cured concrete from turning to white over time, and the reducing agent is a raw material added to improve the workability of the concrete. As an example, it may further include an air-entraining agent (AE), which is an auxiliary material used to even the small air bubbles in the concrete when the concrete construction.

When the mixing ratio for each of the additives exceeds or falls short of the above-mentioned mixing ratio, the curing strength of the main material may be lowered or the effect of each additive may not be obtained to a desired degree, so that the mixing ratio is within a range satisfying the upper mixing ratio. It is preferred to be adjusted.

The shape of the retaining wall block has a natural stone texture and shape, and the front and left and right sides are formed in an irregular shape to have a natural stone shape and texture to facilitate construction, and the upper and lower surfaces are preferably formed flat.

According to another aspect of the present invention, a retaining wall including a visible light active photocatalyst is a block used to construct a retaining wall, and is formed on a substrate formed of a main material including at least one selected from the group consisting of cement, wood, sand and aggregate. A coating material coating layer including a photocatalyst is formed on the photocatalyst, and the photocatalyst may include an inorganic oxide and a metal oxide layer derived from an organometallic compound formed on the inorganic oxide, and may have photoactivity in a visible light region of 400 nm or more.

The coating material coating layer may be formed using a process in which a coating layer may be formed, such as deposition, coating, and spraying. Preferably, the coating material coating layer may be formed by a coating process using a spray. As an example, a protective layer may be further formed on the top of the coating material layer using a liquid vinyl copolymer.

As an example, a primer coating layer using an acrylic latex may be further included between the coating material layer and the retaining wall.

According to one embodiment, the coating material coating layer may further include one or more selected from the group consisting of ocher, illite, acrylic, magnesium oxide and magnesium chloride.

The loess is fine in particles, contains a lot of oxygen, has excellent purifying ability and deodorizing and degreasing properties. It is reported that there are about 200-250 million microorganisms in 1 g of loess, and various enzymes are known to not only cause a circulating action but also release a large amount of far infrared rays, which is beneficial to the human body. Including the ocher can be expected to purify and deodorize the air around the concrete retaining wall without being harmful to the human body.

The illite emits far infrared rays and is safe for the skin, and in addition to the physiological effects on the cells, there are moisturizing effects, shine and elasticity and clean effects, and adsorption and removal of various wastes of the skin such as environmental hormones. Not only is it excellent in capacity, it generates a large amount of negative ions and is known to be excellent in antibacterial activity.

In particular, the illite component has a heavy metal adsorption function such as mercury and cadmium, lead, iron, copper and the like, and has an adsorption function of toxic gases such as ammonia, sulfur dioxide, hydrogen sulfide gas and chlorine gas. Therefore, the illite component can be expected not only to have anion, but also to have an antimicrobial effect on the surface of the retaining wall without harmful to the human body, and to adsorb heavy metals and toxic gases in the air.

The acrylic component may increase the adhesion of ocher and may play a role of improving resistance to ultraviolet rays when exposed to ultraviolet rays for a long time.

The magnesium oxide component may act to absorb carbon dioxide in the air as a compound of magnesium and oxygen.

The magnesium chloride component is strongly absorbent to promote tissue reinforcement, which is contained in seawater, and is slightly natural (2wt%) as a by-product when making salts.

According to one embodiment, the coating layer may be formed to a thickness of 1 mm to 10 mm. When the coating layer is formed to a thickness thinner than the numerical range presented, it may be difficult to implement a sufficient air purification function because it does not contain a sufficient degree of photocatalyst particles, or the peeling of the coating layer may occur. When the coating layer is formed to a thickness thicker than the numerical range shown, the coating layer formation cost increases and the air purification effect of the photocatalyst may also be saturated.

As one example, the retaining wall may include a material having a high hardness, a low coefficient of thermal expansion, and a low specific gravity. In addition, the retaining wall may include a material having high abrasion resistance, porousness, sound absorption, gas adsorption, and water absorption.

As an example, the resin included in the coating layer may include various resin components that may induce dispersion of the photocatalyst and serve as a matrix material. According to an embodiment, the coating layer may further include a polymer resin, a silicone resin, silica, and a water repellent fluorine resin.

The coating layer may be one containing a hydrophobic resin and a hydrophilic resin. The coating layer may include a hydrophobic region derived from a hydrophobic resin and a hydrophilic region derived from a silicone resin or silica at the same time.

By the coexistence of the hydrophobic region and the hydrophilic region, both the hydrophilic material and the hydrophobic material may not be attached to the surface of the coating layer, so that the surface of the coating layer may be maintained to be clean.

According to an embodiment, the coating layer may further include one or more metal materials selected from the group consisting of silver, copper, zinc and platinum group metal elements.

The coating layer to which the metal element is added may kill bacteria and fungi attached to the surface of the coating layer even in a dark place. Therefore, when the metal element is included in the coating layer, antifouling properties can be further improved.

The coating layer may include at least one of platinum group metal elements such as Pt, Pd, Ru, Rh, Ir, and Os. The coating layer to which the platinum group metal element is added may enhance the redox activity of the photocatalyst, thereby improving the degradability of organic contamination and the degradability of harmful gases and odors.

According to one example, the coating layer may further include a reinforcing material. The reinforcing material may include various components, for example, may include one or more selected from the group consisting of lightweight aggregate, foamed urethane, glass wool, and may include a porous material and a plate-like material.

According to an embodiment, the coating layer may include RB ceramics, CRB ceramics, or both.

RB Ceramics and CRB Ceramics are a new concept of carbon-based ceramic materials manufactured using rice bran, which is produced in more than 33 million tonnes annually worldwide.

The RB ceramics and / or CRB ceramics may be a carbon material obtained by mixing and kneading the skim bran obtained from a rice bran, a thermosetting resin, drying the molded body under pressure molding, and then firing the dried molded body in an inert gas atmosphere. . In this case, the thermosetting resin may include a phenol resin, a diaryl phthalate resin, an unsaturated polyester resin, an epoxy resin, a polyimide resin, and a triazine resin.

The RB ceramics or CRB ceramics may be dehydrated at a temperature of 100 degrees or more after molding using a known method for producing RB ceramics or CRB ceramics.

The RB ceramics and / or CRB ceramics may impart high hardness, low coefficient of thermal expansion, low electrical conductivity, and high wear resistance to the coating layer of the retaining wall, and may be porous, sound absorbent, and gas absorbed and absorbed. At the same time, the RB ceramics and / or CRB ceramics are chemically stable and can impart a characteristic that is not a problem even to the strong radicals generated when the photocatalyst acts.

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

According to one embodiment, the inorganic oxide, at least one selected from the group consisting of an oxide containing at least one of Ti, Zn, Al and Sn, the metal oxide layer is 0.001 to 10% by weight compared to the inorganic oxide It is to include iron oxide of%, the photocatalyst, may have a photoactivity under dry conditions of 30% or less humidity.

According to one embodiment, the photocatalyst, an 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 including at least one of Ti, Zn, Al, and Sn.

The metal oxide layer may include a ferrocene-derived iron oxide layer. In this case, the iron content 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 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 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 to the oxide, semiconductor compounds such as CdS, GaP, InP, GaAs, and InPb may be further included.

According to one embodiment, the inorganic oxide, at least one selected from the group consisting of beads, powder, rod, wire, needle and fiber form, the size of the inorganic oxide may be 1 nm to 500 ㎛.

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 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, and the like, depending on the shape.

According to an embodiment, the inorganic oxide may 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 organic compound-derived metal oxide layer 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 ferrocene, and may include iron oxide converted from ferrocene by such a pyrolysis process. The doping step of the organometallic compound will be described in more detail in the following production method.

The organometal oxide-derived metal oxide layer may be, for example, iron oxide derived by at least one of ferrocene and ferrocene derivatives. The ferrocene derivatives are 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 organometallic compound-derived metal oxide layer is 0.001 to 10% by weight relative to the inorganic oxide; 0.01 to 10 weight percent; 0.01 to 3 weight percent; 0.01 to 1.5 wt%; Or 0.01 to 1% by weight. When included in the above range, it is possible to increase the photocatalytic activity in the visible light region to improve the photolysis efficiency. In addition, although the absorption of the visible light region may increase when the content of the metal is increased, since the decrease of the photocatalytic activity may occur due to the increase of the metal content, it is preferable to include the content of the metal within the above range, and more preferably, The metal is iron, and the iron content may be 0.01 to 5% by weight.

As one example, the metal oxide layer derived from the organometallic compound, 0.01 nm or more; 0.1 nm or more; 10 nm or more; Or may have a thickness of 1 nm to 100 nm. When included in the thickness range, it is possible to prevent a decrease in porosity of the photocatalyst by increasing the thickness of the coating layer, and to increase the adsorption amount of water, OH- ions, decomposition targets, etc. on 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 more; 10 nm or more; Or ferrocene-derived iron oxide having a size of 1 nm to 100 nm. The size may mean a length, a diameter, a thickness and the like depending on the shape.

According to an embodiment, the inorganic oxide may 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 kinds of compounds represented by the following Chemical Formula 1.

[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 zero.

As one example, Z may also be nonzero.

As an example, a photocatalyst that is sensitive to visible light by absorbing light in the visible region and introducing iron oxide (Fe _x O _y H _z ), a stable and inexpensive semiconducting material, into the TiO ₂ surface in the form of nano-sized particles. Can be formed.

According to one embodiment of the invention, the photocatalyst, the wavelength region that absorbs light and exhibits a photoreaction may be extended from ultraviolet to visible light region. The photocatalyst may exhibit much better photocatalytic activity than conventional photocatalysts, especially in the visible light region of 400 nm or more. In addition, the photocatalytic reactivity that can be decomposed and decomposed on the surface is improved to have photocatalytic activity in various humidity ranges, and to 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 having 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 an organometallic compound-derived metal oxide on the surface of the inorganic oxide, the adsorption amount of the decomposition target is increased on the surface of the photocatalyst, and the photolysis reactivity is increased to improve the efficiency of the photocatalyst.

According to one embodiment of the invention, the photocatalyst is applied to the decomposition of various harmful substances, that is, it can be used for the treatment of environmental pollutants, odorous substances, organic compounds, acid gases and the like. For example, it is used to adsorb and / or photodecompose 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, light emitting diodes, and the like. More specifically, the gas may be an acid, a basic gas, a VOC (volatile organic compound) such as acetaldehyde, ketones, hydrocarbons of an aromatic hydrocarbon or an aliphatic hydrocarbon (Paraffin-based and Olefin-based), ozone gas, organic, etc. And inorganic glass gases, and more specifically, carbon dioxide, carbon monoxide, NOx, SOx, HCl, HF, NH ₃ , methylamine, formaldehyde, hydrogen sulfide, amine, methylmeraptan, hydrogen, oxygen, nitrogen, methane, paraffin , Olefins and the like. As the liquid, formaldehyde, acetaldehyde, benzene, toluene, toluene, methyl ethyl ketone, trichloroethylene, fungicide, gasoline, diesel, oil, alcohol, Phenols, dyes, and the like, and the solids may be transition metals, precious metals such as Pt and Pd, ions and / or particles such as Hg and Cr, nanoparticles of 100 nm or less, but are not limited thereto.

1 shows a flowchart of a method of manufacturing a photocatalyst proposed in the present invention, which is applied to an embodiment of the present invention. According to an example, after the photocatalyst is prepared in the manner shown in FIG. 1, the photocatalyst is mixed and dispersed in a surface coating layer such as a substrate or a component of the substrate itself in the process of manufacturing the retaining wall described above. It is possible to manufacture a retaining wall in which a coating layer including a photocatalyst according to the present invention is formed.

Hereinafter, with reference to FIG. 1, the contents regarding the manufacturing method of the photocatalyst which shows the said visible light activity which is the characteristic technique of this invention are demonstrated.

The method for preparing the photocatalyst may include preparing an inorganic oxide (110); Forming a metal oxide layer on the inorganic oxide (120); And forming a metal oxide layer derived from an organometallic oxide by heat treatment after forming the metal oxide layer (130).

The preparing of the inorganic oxide may include preparing an inorganic oxide dispersion or applying an inorganic oxide on a substrate, wherein the dispersion is an aqueous solvent, an oily solvent, or a mixture thereof, and the substrate is a silicon substrate. , Wafers, glass substrates, semiconductor substrates, metal substrates, 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 organometal oxide layer, an organometal oxide layer may be formed by a wet coating method, a sputtering method, or a deposition method. As an example, the organometal oxide layer may be a ferrocene layer. 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. The ferrocene layer can be formed. For example, when the TR-CVD is applied, the amount of iron oxide deposited on the inorganic oxide may be easily controlled by controlling the amount of ferrocene, and the process of manufacturing the photocatalyst may be simplified and the photocatalyst may be efficiently provided.

Forming the organometal oxide layer is carried out at room temperature to 120 ℃, preferably 40 ℃ to 100 ℃; More preferably, it may be carried out at 60 ℃ to 100 ℃. That is, the TR-CVD may be performed at 60 ° C. to 100 ° C. in order to induce the deposition by the vaporization process of the organometal oxide layer.

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

The organometallic oxide layer in the forming of the organometallic oxide layer may include 0.01% by weight to 20% by weight of ferrocene, and may form the ferrocene layer.

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

Forming the organometal oxide-derived metal oxide layer, 50 ℃ to 900 ℃; Alternatively 100 ° C. to 800 ° C .; The temperature can be heat treated in two or more steps.

For example, the forming of the organometal oxide-derived metal oxide layer may include 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 may include Heat treatment can be performed at different temperatures. Each of said steps is carried out for 1 minute to 20 hours, respectively, with air, at least 20%; It may be carried out in an air or inert gas atmosphere containing at least 40% 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 the reaction of the organic metal oxide and oxygen. The second heat treatment step may be a post-heat treatment step after the first heat treatment step, and may be an annealing process of removing impurities such as carbides to improve activity and performance of the photocatalyst.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Preparation and Characterization of Photocatalyst

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

However, the following examples are introduced to demonstrate the manufacturing process of the photocatalyst of the present invention and the effect realized therefrom, and only by selecting ferrocene as an organic metal oxide, the contents of the present invention are limited to the following examples. It doesn't happen.

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 It was. More specifically, 0.02 g of ferrocene, an iron precursor, is placed in a container made of quartz on the inner bottom of a reactor made of stainless steel surrounded by a heating band. In the center of the reactor, 3 g of TiO ₂ (TiO ₂ , P-25, Evonik, particle size: 25 nm) is placed in a vessel made of stainless steel wire mesh and placed therein, and then the reactor is sealed with polyimide tape. The reactor was heated at 60 ° C. for 2 hours with a process for depositing ferrocene by TR-CVD vaporization, 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 iron content deposited on TiO ₂ under these conditions is about 0.09 wt%.

Example 2

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

Example 3

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

Example 4

Photocatalyst of 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 iron content deposited on TiO ₂ under these conditions is about 1.81 wt%.

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

The prepared photocatalyst (Fe-TiO ₂ ) is shown in FIG. 4 by comparing transparency and color with TiO ₂ photocatalyst coated with general iron oxide. 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.

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

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

0.13 wt% Fe-TiO ₂ 0.65 wt% Fe-TiO ₂ 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 the specific surface area and the average pore size do not change significantly even when the iron content of Fe-TiO ₂ is changed, and meso pores of Fe-TiO ₂ are formed.

Evaluation example 1

The photocatalyst of Example 1 (Fe-TiO ₂ ) was placed in a volume 5.3 L batch reactor with quartz glass on the top, acetaldehyde initial concentration 66 ppm, dry air (relative humidity: ˜33%, total pressure 760). torr) and the white light retaining wall at room temperature to investigate the photolysis characteristics of acetaldehyde. Acetaldehyde in the reactor was measured closely using gas chromatography. The results are shown in FIG.

FIG. 6 is a graph showing changes in the number of moles of acetaldehyde and the number of moles of carbon dioxide resulting from photolysis reaction of acetaldehyde with visible light (white light) irradiation time at 33% humidity. Looking at it, it can be seen that the photocatalyst (Fe-TiO ₂ ) prepared in Example can be decomposed in acetaldehyde by photocatalytic activity by visible light (white light) irradiation, and the decomposition efficiency in visible light at a ferrocene deposition amount of 0.09 wt%. You can see this biggest. In addition, it can be seen that as the iron content decreases, the acetaldehyde photolysis rate of Fe-TiO ₂ increases.

Evaluation example 2

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

Figure 7 shows the change in the number of moles of carbon dioxide generated as a result of (a) the number of moles of acetaldehyde and (b) the photodegradation of acetaldehyde with the time of visible light irradiation when the experiments of acetaldehyde photolysis under dry conditions and 33% humidity conditions. 7 shows that the slopes of the two graphs are similar in the same acetaldehyde concentration interval indicated by the dotted line, indicating that acetaldehyde photolysis activity is maintained similarly in visible light irrespective of humidity.

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

FIG. 8 shows the change in the number of moles of acetaldehyde and the number of moles of carbon dioxide as a result of the photolysis of acetaldehyde with the time of visible light irradiation when repeatedly used in the acetaldehyde photolysis experiment at 33% humidity. 8 is a graph showing that high photocatalytic activity is maintained even in the repeated photolysis experiment.

Overall, the present invention, iron oxide deposited TiO ₂ (hereinafter Fe-TiO ₂ ) was utilized in the photolysis experiment of acetaldehyde, one of the representative volatile organic compounds, and acetaldehyde photodegradation activity of Fe-TiO ₂ according to the iron oxide content Was compared. As a result, the photodegradation activity of acetaldehyde of Fe-TiO ₂ was the highest when the iron content was about 0.09 wt%, and about 70% of the initial acetaldehyde concentration (~ 95 mol ppm) was decreased within 20 hours. In general, the activity of the photocatalyst is greatly affected by the humidity, but Fe-TiO ₂ prepared in the present invention showed similar catalytic activity under dry conditions and humidity 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, when the photocatalytic activity of Fe-TiO ₂ was greatly influenced by the iron content, it can be seen that the photocatalytic activity is more important for the electronic structure of the interface between the deposited iron oxide nanoparticles and TiO ₂ than the surface structure. . In addition, as the iron content decreases through the transmission electron microscope, the size of the iron oxide particles present on the surface is reduced, and the photocatalytic activity may be increased when the iron oxide particles having a level of 1 to 3 nanometers are deposited. Based on the analytical results, Fe-TiO ₂ absorbs light in the visible range and the most efficient separation of electron / hole pairs by oxygen / nanoparticles when very small iron oxide nanoparticles have a content of about 0.09 wt%. By reacting with water to generate radicals, acetaldehyde can be rapidly decomposed. 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 active sites, the activity of the photocatalyst is reduced, which is pointed out as one of the biggest problems of the photocatalyst. However, Fe-TiO ₂ prepared in the present invention was confirmed that the catalyst activity was maintained the same even in repeated acetaldehyde photolysis experiments, and thus there was no problem of lowering catalyst activity.

Preparation of Photocatalyst Coating Layer on Surface of Retaining Wall Block

The photocatalyst prepared by the above-described method was prepared in the form of a composition, and a coating layer was formed to a thickness of 5 mm (coated) on a block of a generally retaining wall (concrete based block), and dried. As a result of measuring the air purification effect, it was confirmed that the photocatalyst functions in the same manner even in the form of the coating layer.

Although the embodiments have been described by the limited embodiments and the drawings as described above, various modifications and variations are possible to those skilled in the art from the above description. For example, the described techniques may be performed in a different order than the described method, and / or the described components may be combined or combined in a different form than 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 within the scope of the claims that follow.

Claims (10)

As a block used to build retaining walls,
The photocatalyst is dispersed and formed in the main material including one selected from the group consisting of cement, wood, sand and aggregate,
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 contain 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 includes iron oxide that is 0.001 to 10% by weight relative to the inorganic oxide,
The photocatalyst is one having photoactivity under dry conditions of 30% or less humidity,
Retaining wall block containing visible light active photocatalyst.
The method of claim 1,
The retaining wall block is obtained by curing the mortar mixed with water and a photocatalyst in the main material and stirred,
Retaining wall block containing visible light active photocatalyst.
The method of claim 1,
Per 100 parts by weight of the main material,
1 to 5 parts by weight of pigment;
0.1 to 3 parts by weight of a coarse agent;
0.5 to 5 parts by weight of anti-whitening agent; And
0.5 to 5 parts by weight of a reducing agent;
Further comprising an additive comprising at least one selected from the group consisting of,
The photocatalyst is 0.1 to 10 parts by weight based on 100 parts by weight of the main material,
Retaining wall block containing visible light active photocatalyst.
As a block used to build retaining walls,
A coating material coating layer including a photocatalyst is formed on a substrate formed of a main material including one selected from the group consisting of cement, wood, sand and aggregate,
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 contain 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 includes iron oxide that is 0.001 to 10% by weight relative to the inorganic oxide,
The photocatalyst is one having photoactivity under dry conditions of 30% or less humidity,
Retaining wall block containing visible light active photocatalyst.
The method of claim 4, wherein
The coating material coating layer is one that further comprises one or more selected from the group consisting of ocher, illite, acrylic, magnesium oxide and magnesium chloride,
Retaining wall block containing visible light active photocatalyst.
delete delete The method according to claim 1 or 4,
The inorganic oxide does not contain an inorganic oxide containing iron,
The metal oxide layer, the ferrocene deposited on the inorganic oxide is heat-treated,
Retaining wall block containing visible light active photocatalyst.
The method according to claim 1 or 4,
The metal oxide is one containing one or more of the compounds represented by the following formula (1),
Retaining wall block containing visible light active photocatalyst.

[Formula 1]
Me _x O _Y H _Z
(Me is at least one metal element of Groups 1 to 3, X, Y and Z are each selected from 0 to 3, and X and Y are not 0.)
The method according to claim 1 or 4,
The specific surface area of the photocatalyst is 5 (m ² / g) or more, the average pore size is 50 nm or less,
Retaining wall block containing visible light active photocatalyst.

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