KR102089491B1 - Clay concrete comprising visible light active photocatalys - Google Patents

Abstract

The present invention relates to a clay concrete composition and clay concrete comprising a visible light active photocatalyst. The present invention comprises: clay comprising at least one selected from the group consisting of aggregate, silica, sand and gravel; and a photocatalyst in a particle phase, wherein 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.

Description

CLEAR CONCRETE COMPRISING VISIBLE LIGHT ACTIVE PHOTOCATALYS containing visible light active photocatalyst

The present invention relates to a soil concrete, and more particularly, to a composition for concrete composed of soil.

Most commonly known concrete is concrete mixed with sand and gravel as cement as a construction material.

However, the collection of aggregates, such as sand and gravel, has emerged as a major cause of environmental destruction, and has reached the limit that the aggregate-based concrete can no longer be used in the state where the aggregates have run out.

Accordingly, a technology for producing concrete by mixing soil, which is the most common and appears as an optimal element for human health, was developed. However, the soil did not fuse well with the components constituting the concrete. Soil concrete is derived by improving this and mixing well with other materials of concrete and fusion.

In recent years, techniques for mixing the soil concrete with an ocher composition and using a far-infrared ray known to be generated from ocher have been developed, and techniques for mixing the soil concrete with additional components beneficial to the human body have been developed.

Meanwhile, 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. The 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. In other words, electrons in the conduction band reduce oxygen to generate super oxyanions, and holes in the valence band oxidize moisture to form hydroxy radicals (OH ·). Due to 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 ) is advantageous in that it is harmless to the human body, has excellent photocatalytic activity, has excellent light corrosion resistance, and is inexpensive. Titanium dioxide (TiO ₂ ) absorbs and reacts with ultraviolet rays of 388 nm or less to generate electrons (conduction 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, the band gap energy (wavelength of 380nm or more) of titanium dioxide (TiO ₂ ) powder is obtained from sunlight, and since about 2% of the light can be used, smooth catalytic activity in the visible wavelength (400 ~ 800nm), which is the main wavelength of sunlight It is difficult to have. 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 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 of soil concrete, air pollution in modern society, and supplementation for the insufficient functions of photocatalyst, and the present invention is formed by introducing a doping process of an organometallic compound. Inorganic oxide-based photocatalyst, which has excellent photocatalytic activity in the light region, was developed and applied to soil concrete.

One embodiment of the present invention is applied by including a photocatalyst activated in a newly developed visible light in a composition for soil concrete.

One embodiment of the present invention is to provide an earth concrete with a function of purifying ambient air even when exposed to light by including an inorganic oxide-based photocatalyst and having a photolysis function. These technologies are in line with the recent development trend of soil concrete, and have solved all of the problems of photocatalysts, which have been difficult to commercialize and modern people's desire for air purification.

According to an embodiment of the present invention, it is to provide a technology in which harmful substances in ambient air are removed only by preparing a structure using the earth concrete of the present invention without a separate air cleaner.

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.

Soil concrete comprising a visible light active photocatalyst according to an aspect of the present invention, the soil comprising at least one selected from the group consisting of aggregate, silica, sand and gravel; And a photocatalyst on the particle. The photocatalyst on the particle 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 soil is from 50% to 95% by weight, the photocatalyst is from 0.1% to 20% by weight and may include additives for the balance concrete.

According to one embodiment, the soil concrete further comprises at least one of pigment and ocher, the weight of the pigment and ocher may be less than 1% by weight.

According to one embodiment, the soil concrete further comprises cement and water, the weight of the cement and water may be 1 to 20% by weight.

According to one embodiment, the soil concrete further includes a solidifying agent and a binder, and the weight sum of the solidifying agent and the binder may be 1 wt% to 10 wt%.

According to an embodiment, the soil concrete may further include fibers and iron oxide particles.

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

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 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 metal oxide may include one or more of the compounds represented by Chemical 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 of the present invention, it is possible to achieve an effect of reducing harmful substances in ambient air by simply providing a structure with concrete and exposing it to light.

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 is prepared, and to provide earth concrete to which the photocatalyst is applied You can.

The soil concrete 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 ambient air even in various exposed environments.

The soil concrete containing the visible light-activated photocatalyst proposed in the present invention may be activated by receiving light including a visible light region. Through this, the earth concrete proposed in the present invention can reduce the fear of air pollution of modern people, and it is possible to purify the surrounding air without the need for a separate air purification device, so that it can be applied to various environments where concrete structures can be applied. Can be applied as

The present invention can provide a soil concrete containing an inorganic oxide-based photocatalyst prepared by a simple and economical method, and the soil concrete provided with the inorganic oxide-based photocatalyst includes a photocatalyst that can be activated even under dry conditions. In addition, it has the ability to decompose volatile organic compounds with high efficiency and excellent stability in response to light in the visible light region.

Specifically, the photocatalyst proposed in one embodiment of the present invention does not exclude the possibility of being mixed and applied to various general concretes for manufacturing buildings, structures, and facilities, as well as soil concrete.

1 is a photograph of the surface of visible light-activated earth concrete prepared according to an embodiment of the present invention.
Figure 2, according to an embodiment of the present invention, shows a flow chart of a method of manufacturing a photocatalyst applied to the present invention.
Figure 3, 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 present invention.
Figure 4, according to an embodiment of the present invention, illustratively shows the manufacturing process of the photocatalyst applied to the present invention.
5 shows an image of a photocatalyst applied to the present invention prepared according to an embodiment of the present invention.
6 shows a TEM image of a photocatalyst prepared according to an embodiment of the present invention.
7 shows the evaluation results of the photolysis performance of the photocatalyst prepared according to the embodiment of the present invention.
Figure 8 shows the evaluation results of the photolysis performance according to the humidity of the photocatalyst prepared according to the embodiment of the present invention.
Figure 9 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.
FIG. 10 is a photograph of an experiment in which methylene blue on the surface of soil concrete is removed by simply exposing it to light, for soil concrete prepared according to an embodiment of the present invention.
11 is a photograph confirming that methylene blue on the surface of the earth concrete is removed by simply exposing the earth to the earth concrete prepared according to another embodiment of the present invention.

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

Various changes can 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, the terms "include" or "have" are intended to indicate the presence of features, numbers, steps, actions, components, parts or combinations thereof described in the specification, one or more other features. It should be understood that the existence or addition possibilities of fields or numbers, steps, actions, components, parts or combinations thereof are not excluded in advance.

Unless defined otherwise, 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 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 properly express a preferred embodiment of the present invention, which may vary according to a user's, operator's intention, or customs 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 is in contact with the other member but also another member 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 soil concrete 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.

1 is a photograph of the surface of visible light-activated earth concrete prepared according to an embodiment of the present invention.

Hereinafter, each configuration constituting the present invention will be described in detail with reference to FIG. 1.

Soil concrete comprising a visible light active photocatalyst according to an aspect of the present invention, the soil comprising at least one selected from the group consisting of aggregate, silica, sand and gravel; And a photocatalyst on the particle. The photocatalyst on the particle 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 present invention relates to a soil concrete capable of performing a function of purifying the ambient air only by being actually installed and exposed to light by including photocatalyst particles in a part of the composition of the soil concrete. Moreover, unlike the conventional photocatalysts, the photocatalyst applied to the soil concrete 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. Therefore, even if the concrete is exposed to the outside, the air in the surrounding space can be purified with high efficiency without a special driving device.

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

The present invention is expected to have a function of purifying the ambient air in addition to the advantages of eco-friendly, fast setting speed and stable of general soil concrete.

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. 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 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 realized in a metal oxide layer derived from an organometallic compound.

The photocatalyst particles may be formed on an outer surface exposed to the light of the soil concrete.

The soil referred to in the present invention encompasses various ingredients that may be included in the concept of soil in general in addition to the ingredients listed.

According to one embodiment, the soil is from 50% to 95% by weight, the photocatalyst is from 0.1% to 20% by weight and may include additives for the balance concrete.

If the soil is less than 50% by weight, it may not be a soil concrete that is generally defined. When the soil is mixed in excess of 95% by weight, there is a problem that it cannot function properly as concrete because it cannot be properly fused with other components.

When the photocatalyst is included less than 0.1% by weight, there is a problem that the air purification function is substantially insignificant, and when it is included at 20% by weight or more, the unit price increases, the air purification function is saturated, and the durability of the structure decreases when the structure is manufactured from concrete Problems may arise.

The additive may be, for example, a mixture of one or more of a dispersant, an AE agent, a water reducing agent, a fluidizing agent, and a quick-setting agent. Through this, while promoting the curing reaction of the concrete, there is an effect that can increase the strength. Also, the additive may include one or more of a solidifying agent, an organic binder, an inorganic binder, and water.

According to one embodiment, the soil concrete further comprises at least one of a pigment and ocher, the weight of the pigment and ocher may be 0.1 to 5% by weight.

The pigment and ocher may be included in trace amounts in the present invention.

The pigment means a component that can coat the color of the soil concrete, and may perform a role of applying color, luster to the soil concrete, preventing corrosion or damage, and increasing strength.

The ocher refers to fine sand or clay showing a yellowish brown or pale yellow color, and may function to benefit the human body when emitting a structure by emitting infrared rays.

At this time, if the weight of the pigment and ocher in the soil concrete is more than 5% by weight, when the soil concrete is packaged, the pigment or ocher is easily peeled off and released, or a problem that the strength of concrete is deteriorated may occur. have. When the weight of the pigment and ocher is less than 0.1% by weight, the color expression is not effective due to the trace amount of pigment or the effect of blocking absorption of ultraviolet and radiant heat by adding a trace amount of ocher, as well as the emission of far infrared rays. Problems can arise that make it difficult to expect properly.

As an example, the ocher may have a particle size of 1 mm or less. If the particle size of the ocher is small, it is easily mixed with other components in the soil concrete, and a smooth surface can be realized during packaging.

According to one embodiment, the soil concrete further comprises cement and water, the weight of the cement and water may be 1 to 20% by weight.

The cement may include alumina cement. However, when the excess amount of the alumina cement is included, there may be a problem that resistance to freeze-thaw is reduced.

The cement may have high chemical resistance and form a structure of a compact hardened body when hardened. The cement may be to implement high strength, promote initial hardening, and prevent deterioration of the hydraulic properties of concrete by fine particles and organic matter. The cyclent may be to enhance strong dispersibility and cohesiveness with soil. The weight of the cement and water may be preferably 10% by weight or more, and more preferably 15% by weight or more.

According to one embodiment, the soil concrete further includes a solidifying agent and a binder, and the weight sum of the solidifying agent and the binder may be 1 wt% to 10 wt%.

The solidifying agent may include one or more components of calcium, magnesium, waste powder, stone powder, incineration ash, and coal ash. The solidifying agent may be included in powder form.

The binder may include an organic binder and / or an inorganic binder. The solidifying agent

According to an embodiment, the soil concrete may further include fibers and iron oxide particles.

The fiber may include one or more selected from the group consisting of fiber, glass, steel, and carbon. When the fiber is included, it is possible to expect a reinforcement effect of the ocher component when the ocher component is included while preventing cracks or cracks in the soil concrete structure.

When the iron oxide particles are included, a natural soil color may be provided, and an effect of reinforcing durability and increasing density due to iron components may be expected.

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

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.

The photocatalyst may include an inorganic oxide; And a metal oxide layer formed on the inorganic oxide. Including, 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, the photocatalytic activity in the visible light region may be increased to improve photolysis efficiency. In addition, although the absorption of the visible light 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 above thickness range, the porosity of the photocatalyst can be prevented due to the 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 metal oxide 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 a stable and inexpensive semiconductor material, iron oxide (Fe _x O _y H _z ), in the form of nano-sized particles into the TiO ₂ surface Can form.

According to an embodiment of the present invention, the photocatalyst, the wavelength region that absorbs light and exhibits a photoreaction may be extended from ultraviolet light to visible light. The photocatalyst can exhibit much better photocatalytic activity than conventional photocatalysts, particularly 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 humidity of 30% or less.

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 on 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 one embodiment of the present invention, the photocatalyst is applied to the decomposition of various harmful substances, that is, it can be used for the 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.

2 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 the photocatalyst in the manner shown in FIG. 2, in the process of preparing and dispersing the soil concrete described above, the soil concrete according to an embodiment of the present invention may be prepared by mixing and dispersing the photocatalyst.

Hereinafter, with reference to FIG. 2, 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 forming of the organic metal oxide layer, an organic metal oxide film may be formed using a wet coating method, sputtering method, or 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 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 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 contains 0.01% to 20% by weight of ferrocene relative 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; Or 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, 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 may 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 and characterization of photocatalyst

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

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

Example 1

By using a TR-CVD (temperature controlled chemical vapor deposition) reactor of Figure 3, and utilizing the temperature controlled chemical vapor deposition method shown in Fig producing a photocatalyst (Fe-TiO ₂₎ of the iron oxide particles in the nano-scale deposited on the TiO ₂ Did. More specifically, 0.02 g of Ferrocene, a precursor of iron, 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 and 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 carried out, 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 content of iron deposited on TiO ₂ under these 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 iron content deposited on TiO ₂ under the conditions is about 1.81 wt%.

The prepared photocatalyst (Fe-TiO ₂ ) is compared with a TiO ₂ photocatalyst coated with a general iron oxide and is shown in FIG. 5 by comparing transparency and color. 5, 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. 6. 6 shows that as the iron content decreases, the size of the iron oxide particles deposited on the Fe-TiO ₂ surface decreases.

The specific surface area (BET) and BJH average pore size through the nitrogen adsorption analysis of the prepared photocatalyst (Fe-TiO ₂ ) were 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 photo-decomposition properties of acetaldehyde were analyzed by irradiating the visible light region with white earth concrete at room temperature. Acetaldehyde in the reactor was measured by gas chromatography. The results are shown in FIG. 7.

FIG. 7 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 resulting from 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 acetaldehyde photodecomposition rate of Fe-TiO ₂ is.

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

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

FIG. 9 shows (a) acetaldehyde mole number change and (b) carbon dioxide mole number change resulting from acetaldehyde photolysis reaction according to visible light irradiation time, when repeatedly used in 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.

Collectively, the present invention, TiO ₂ (hereinafter Fe-TiO ₂ ) on which iron oxide was deposited, was utilized in photodegradation experiments of acetaldehyde, 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 drying 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. 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 pair is most efficiently separated to remove oxygen / Reacts 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.

Preparation and Characterization of Soil Concrete Containing Photocatalyst

Example 1

5% by weight of the photocatalyst particles using ferrocene prepared above, soil (coarse aggregates and fine aggregates) 80% by weight, ocher and pigment 0.5% by weight, cement 12% by weight, the balance of the soil concrete of Example 1 It was prepared.

A disk-like structure was prepared using the soil concrete, and the MB removal performance of the soil concrete was evaluated when exposed to light (light source Blue LED) using methylene blue (MB).

FIG. 10 is a photograph of an experiment in which methylene blue on the surface of soil concrete is removed by simply exposing it to light, for soil concrete prepared according to an embodiment of the present invention.

-Step 1: After spraying 0.5 mL of 75 ppm MB in IPA on the sample, when IPA is dried, confirm that the photo and MB remain on the surface.

-Step 2: After spraying 0.5 mL of water on the sample of step 1, after 1 minute, it is confirmed that the photo, MB does not penetrate into the sample by water and remains on the surface.

-Step 3: Step 2 After spraying 0.5 mL of water again on the sample, after 30 minutes of irradiation with light, it was confirmed that the MB on the surface of the sample was removed. MB remains on the surface.

Example 2

5% by weight of the photocatalyst particles using ferrocene prepared above, 0.3% by weight of ocher and pigment, 7.5% by weight of a solidifying agent and binder, and residual soil (aggregate and silica sand) were mixed to prepare soil concrete of Example 2.

A disk-like structure was prepared using the soil concrete, and the MB removal performance of the soil concrete was evaluated when exposed to light (light source Blue LED) using methylene blue (MB).

11 is a photograph confirming that methylene blue on the surface of the earth concrete is removed by simply exposing the earth to the earth concrete prepared according to another embodiment of the present invention.

-Step 1: After spraying 0.5 mL of 75 ppm MB in IPA on the sample, when IPA was dried, it was confirmed that MB remained on the surface.

-Step 2: Step 1 After spraying 0.5 mL of water on the sample and drying it, it was confirmed that the photo and MB remained on the surface without water penetrating into the sample.

-Step 3: Step 2 After spraying 0.5 mL of water again on the sample, after 30 minutes of light irradiation, it was confirmed that the MB on the surface of the sample was completely removed.

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)

Soil comprising at least one selected from the group consisting of aggregate, silica, sand and gravel; And
Particle photocatalyst; includes,
The photocatalyst on the particles includes inorganic oxide particles and a metal oxide layer derived from an organometallic compound formed on the inorganic oxide particles, and has photoactivity in a visible light region of 400 nm or more,
The metal oxide layer includes 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 comprises 0.001 to 10% by weight of iron oxide compared to the inorganic oxide,
The photocatalyst is to have photoactivity under dry conditions of humidity of 30% or less,
Earthen concrete containing visible light active photocatalyst.
According to claim 1,
The soil is 50% to 95% by weight,
The photocatalyst is 0.1 to 20% by weight
Containing additives for the remainder concrete,
Earthen concrete containing visible light active photocatalyst.
According to claim 1,
Further comprising at least one of pigment and ocher,
The weight of the pigment and ocher is less than 1% by weight,
Earthen concrete containing visible light active photocatalyst.
According to claim 1,
More cement and water,
The weight of the cement and water is 1 to 20% by weight,
Earthen concrete containing visible light active photocatalyst.
According to claim 1,
Further comprising a solidifying agent and a binder,
The weight ratio of the solidifying agent and the binder is 1 to 10% by weight,
Earthen concrete containing visible light active photocatalyst.
According to claim 1,
It contains more fiber and iron oxide particles.
The fiber and the iron oxide particle weight sum is 0.1 to 2% by weight,
Earthen concrete containing visible light active photocatalyst.
delete delete 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,
Earthen concrete containing visible light active photocatalyst.
According to claim 1,
The metal oxide is to include one or more of the compounds represented by the formula (1),
Earthen concrete 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.)

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