KR102070720B1 - Concrete block with inorganic oxide based photocatalyst - Google Patents

Abstract

The present invention relates to a concrete block with an inorganic oxide-based photocatalyst, which has excellent photocatalytic activity in a visible light region by applying the inorganic oxide-based photocatalyst to the concrete block as a finishing layer, and is capable of decomposing environmental pollutants such as volatile organic compounds with excellent photodegradation efficiency even in various humidity and temperature areas and, more specifically, to a concrete block comprising cement, aggregate, blended water and photocatalyst powder, wherein the photocatalyst comprises inorganic oxide and a ferrocene-derived iron oxide layer formed on the inorganic oxide.

Description

Concrete block with inorganic oxide based photocatalyst

The present invention can apply an inorganic oxide-based photocatalyst to the concrete block as a finishing layer can have excellent photocatalytic activity in the visible light region, and decompose environmental pollutants such as volatile organic compounds with excellent photolysis efficiency in various humidity and temperature ranges The present invention relates to a concrete block to which an inorganic oxide-based photocatalyst is applied.

Recently, Korea has achieved remarkable industrialization, but it is also true that side effects caused severe environmental pollution.

Especially in the case of air pollution, it is exposed to various volatile organic compounds (VOC), nitrogen oxides, sulfur oxides and other harmful gases by using synthetic resin materials, synthetic resin adhesives and synthetic resins in offices and living spaces. A lot of diseases and atopic dermatitis are occurring.

Therefore, it is a very effective way to apply concrete materials to concrete products that can decompose and reduce pollutants exposed to the air by using concrete with high frequency of contact with the atmosphere as a structure. In the same vein, various methods of granting the same have been studied.

Among them, a concrete product using a photocatalytic technique has been disclosed as a conventional technique.

In general, photocatalyst is a material that can decompose various organic materials and microorganisms by light and can decompose air pollutants using only solar energy without introducing other energy from the outside. Since mid-Japan, research and development have been actively conducted to apply to building materials such as concrete and to use them for air purification and water purification.

Republic of Korea Patent No. 10-935128 introduces the technical content of "photocatalyst coating composition comprising titanium dioxide coated with hydroxy apatite having a water-repellent and atmospheric purification function".

In the above-mentioned prior art, a photocatalyst coating composition for applying a photocatalyst coating composition to a concrete secondary product, wherein the aqueous emulsion binder 1 is prepared by copolymerizing 1-10% by weight of titanium dioxide coated with hydroxyapatite and polysiloxane and acrylic resin. Organic emulsions such as aqueous emulsion binders, thickeners, dispersants, and preservatives on the concrete surface, including ~ 5% by weight, thickener 0.1-0.5%, dispersant 0.1-5%, preservative 0.1-10%, and water 85.5-7.7% by weight. The photocatalyst coated with apatite with a compound is coated and bonded.

Generally, titanium dioxide (TiO ₂ ) is harmless to the human body, has excellent photocatalytic activity, excellent corrosion resistance, and low cost, and thus is commonly used as a photocatalyst as in the related art.

Titanium dioxide (TiO ₂ ) absorbs and reacts with ultraviolet rays of 388 nm or less to generate electrons (conductor bands) and holes (valence bands) .In this case, the ultraviolet rays used as light sources are lamps, incandescent lamps, 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 are decomposed by the electrons and holes if contaminants or the like adsorb to the surface before recombination.

However, the bandgap energy (TiO ₂ ) of the bandgap (380nm or more) is obtained from sunlight, and because it can use about 2% of the light, it has a smooth catalytic activity in the visible light region (400 ~ 800nm), which is the main wavelength of sunlight There is difficulty.

In other words, in order to respond to visible light, it is essential to effectively reduce the band gap of the photocatalyst and to efficiently separate the electron / hole pairs generated through light absorption. For titanium dioxide (TiO ₂ ), the efficiency of the visible light-sensitive photocatalyst is still It is far below the level to be commercialized in the air clean field.

Korea Patent Registration No. 10-935128

Therefore, an object of the present invention is to apply an inorganic oxide-based photocatalyst as a finishing layer to the concrete block can have excellent photocatalytic activity in the visible light region, environmental pollutants such as volatile organic compounds with excellent photolysis efficiency in various humidity and temperature range It is to provide a concrete block applied with an inorganic oxide-based photocatalyst capable of decomposing.

As a means for solving the above problems, the concrete block to which the inorganic oxide-based photocatalyst of the present invention is applied (hereinafter referred to as 'concrete block of the present invention') is used in a concrete block including cement, aggregate, blended water, and photocatalyst powder. The photocatalyst includes an inorganic oxide and a ferrocene-derived iron oxide layer formed on the inorganic oxide.

As one example, the concrete block, the base layer containing the cement, aggregate and blending water; And a finishing layer laminated on the upper surface of the base layer and including cement, aggregate, pigment, blended water, and photocatalyst powder.

As one example, the concrete block, the block body is manufactured by molding the raw materials including cement, aggregate and blending water; And a finish coating layer coated on the upper surface of the block body and including a surface strengthening agent in which photocatalyst powder is dispersed.

As one example, the photocatalyst may have an iron content of 0.001 to 10% by weight relative to the inorganic oxide in the ferrocene-derived iron oxide layer.

As one example, the ferrocene-derived iron oxide layer may be a heat treatment of the ferrocene deposited on the inorganic oxide.

As one example, 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.

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

As one example, the photocatalyst may have photoactivity in a visible light region of 400 nm or more.

As one example, the photocatalyst may be one having photoactivity under dry conditions of 30% or more humidity.

As an example, the ferrocene-derived iron oxide may include one or more of the compounds represented by the following Chemical Formula 1. Fe _X O _Y H _Z (X, Y and Z are each selected from 0 to 3, X and Y is not 0.)

As one example, the photocatalyst may have a specific surface area of 5 (m 2 / g) or more and an average pore size of 50 nm or less.

As such, the concrete block of the present invention can have an excellent photocatalytic activity in the visible region by providing an inorganic oxide-based photocatalyst in a simple and economical manner and applying it as a finishing layer to the concrete block, and excellent in various humidity and temperature ranges. Photodegradation efficiency can decompose environmental pollutants such as volatile organic compounds, and of course, has an effect of having an air purification function.

1 illustrates an embodiment of a concrete block of the present invention.
2 shows a flowchart of a method of preparing an inorganic oxide based photocatalyst according to an embodiment of the present invention.
FIG. 3 exemplarily shows a configuration of a TR-CVD reactor used in a process for preparing an inorganic oxide based photocatalyst according to an embodiment of the present invention.
4 exemplarily illustrates a process for preparing an inorganic oxide based photocatalyst according to an embodiment of the present invention.
5 shows an image of an inorganic oxide based photocatalyst prepared according to an embodiment of the present invention.
6 shows a TEM image of an inorganic oxide based photocatalyst prepared according to an embodiment of the present invention.
Figure 7 shows the evaluation results of the photolysis performance of the inorganic oxide based photocatalyst prepared according to the embodiment of the present invention.
8 shows evaluation results of photodegradation performance according to humidity of an inorganic oxide based photocatalyst prepared according to an embodiment of the present invention.
Figure 9 shows the results of the stability evaluation of photodegradation performance according to the repeated photolysis experiment of the inorganic oxide based photocatalyst prepared according to the embodiment of the present invention.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, the term or word used in the present specification and claims is based on the principle that the inventor can appropriately define the concept of the term in order to best describe his or her invention. It should be interpreted as meanings and concepts corresponding to the technical idea of

Concrete block 10 of the present invention includes cement, aggregate, blended water and photocatalyst powder, the photocatalyst is characterized in that it comprises an inorganic oxide and a ferrocene-derived iron oxide layer formed on the inorganic oxide.

That is, the concrete block 10 of the present invention may include an inorganic oxide-based photocatalyst, and may also exhibit an air purification function in addition to the photocatalytic function by the action of the photocatalyst. For example, it may have a photodegradation function and / or an air purification function by photoactivity such as volatile substances, odor substances, pollutants, and the like.

The inorganic oxide based photocatalyst may be a photocatalyst bound or impregnated with a coating on a concrete block substrate, or a molded body including the photocatalyst may be stacked.

Concrete block 10 according to an embodiment of the present invention may be used as a block for blocking, including the base layer 100 and the finishing layer 200.

Referring to FIG. 1, the base layer 100 may include cement, aggregate, and compounded water, and the finishing layer 200 may be laminated on the upper surface of the base layer 100. Photocatalyst powder may be included.

At this time, the selection of cement, aggregate and blending water, and blending ratio, etc. can be carried out in various ways to manufacture a known concrete product, a detailed description thereof will be omitted.

The photocatalyst included as finishing for the concrete block 10 of the present invention may be manufactured in powder form, but the present invention is not limited thereto.

The photocatalyst included in the concrete block 10 of the present invention may be a photocatalyst prepared based on an inorganic oxide.

As an example, the photocatalyst may include a ferrocene-derived iron oxide layer formed by an inorganic oxide and a ferrocene doping process. The ferrocene-derived iron oxide layer may be formed as a coating layer on an inorganic oxide, and may improve light absorption and photocatalytic efficiency in the visible light region.

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 , SrTiO ₃ , Fe ₂ O ₃ , Ta ₂ O ₅ , WO ₃ , SnO ₂ , BiO ₃ , NiO, Cu ₂ O, SiO, SiO ₂ , MoS ₂ , InPb , RuO ₂ , CeO ₂ , and the like.

In addition to the oxide, it may further include a semiconductor compound such as CdS, GaP, InP, GaAs, InPb.

The inorganic oxide includes at least one selected from the group consisting of beads, powders, rods, wires, needles and fibers, the inorganic oxide has 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. Herein, the size may mean a diameter, a thickness, a length, etc. according to a shape.

The ferrocene-derived iron oxide layer is 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 ferrocene doping process will be described in more detail in the following manufacturing method.

The ferrocene-derived iron oxide is an iron oxide derived from at least one of ferrocene and ferrocene derivative, and the ferrocene derivative is ferrocene aldehyde, ferrocene ketone, ferrocene carboxylic acid, ferrocene alcohol, phenol or ether compound, nitrogen-containing ferrocene compound, sulfur- Containing ferrocene compound, phosphorus-containing ferrocene compound, silicon-containing ferrocene compound, 1,1'-di-copper ferrocene, ferrocene boricacid, ferrocenyl cuprus acetyllite (ferrocenyl cuprous acetylide) and bisferrocenyl titanocene (bisferrocenyl titanocene) may include at least one selected from the group consisting of.

Iron content in the ferrocene-derived iron 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 can increase the photocatalytic activity in the visible light region to improve the photolysis efficiency. In addition, the increase in the iron content may increase the absorption in the visible light region, but may decrease the photocatalytic activity due to the increase in the iron content it is preferable to include the iron content in the above range and more preferably the iron The content of may be 0.01 to 1% by weight.

The ferrocene-derived iron oxide layer is 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 ferrocene-derived iron oxide layer is 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. Here, the size may mean a length, a diameter, a thickness, etc. according to the shape.

The ferrocene-derived iron oxide may include one or more of the compounds represented by Formula 1 below.

[Formula 1]

Fe _X O _Y H _Z

Wherein X, Y and Z are each selected from 0 to 3, and X and Y are not zero.

In other words, iron oxide (Fe _X O _Y H _Z ), which absorbs light in the visible light region and is a stable and inexpensive semiconducting material, is introduced into the TiO ₂ surface in the form of nano-sized particles to form a photocatalyst that is sensitive to visible light. Can be.

The inorganic oxide-based photocatalyst according to an embodiment of the present invention extends from the ultraviolet light to the visible light region by absorbing light and exhibits excellent photocatalytic activity in the visible light region of 400 nm or more.

In addition, the photocatalytic reactivity to decompose and decompose the decomposition on the surface is improved to have a photocatalytic activity in a variety of humidity range, it can exhibit excellent photocatalytic activity even in dry conditions of less than 30% humidity.

The inorganic oxide based photocatalyst according to an embodiment of the present invention is 5 (㎡ / g) or more; 5 (m 2 / g) to 1000 (m 2 / g); Or from 5 (m 2 / g) to 100 (m 2 / g), with an average pore size of 50 nm or less. That is, by introducing ferrocene-derived iron oxide on the surface, the adsorption amount of the decomposition target on the surface of the photocatalyst can be increased, and the photolysis reactivity can be increased to improve the efficiency of the photocatalyst.

And the inorganic oxide based photocatalyst according to an embodiment of the present invention 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.

Specifically, the gas may be an acid, a basic gas, acetic aldehydes, volatile organic compounds (VOCs) such as ketones, aromatic hydrocarbons and aliphatic hydrocarbons (Paraffin-based and Olefin-based) hydrocarbons, ozone gas, organic and inorganic Glass gas and the like, and more specifically, carbon dioxide, carbon monoxide, NOx, SOx, HCl, HF, NH ₃ , methylamine, formaldehyde, hydrogen sulfide, amine, methylmeraptan, hydrogen, oxygen, nitrogen, methane, paraffin, olefin And the like.

As the liquid, formaldehyde, acetaldehyde, benzene, benzene, toluene, MEK (Methyl Ethyl Ketone), trichloroethylene, fungicide, gasoline, diesel, oil, alcohol, It may be a phenol, a dye, and the like, and the solid 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, and the like.

Hereinafter, with reference to Figure 2 looks at the manufacturing method of the inorganic oxide based photocatalyst of the present invention.

In the method for preparing an inorganic oxide based photocatalyst according to an embodiment of the present invention, after preparing an inorganic oxide (S110), forming a ferrocene layer on the inorganic oxide (S120), and forming the ferrocene layer, The heat treatment may include forming a ferrocene-derived iron oxide layer (S130).

The preparing of the inorganic oxide (S110) is a step of preparing an inorganic oxide dispersion or applying an inorganic oxide on a substrate, the dispersion is an aqueous solvent, an oily solvent or a mixture of the two, the substrate is silicon Substrate, wafer, glass substrate, semiconductor substrate, 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 ferrocene layer (S120), the ferrocene layer may be formed using a wet coating method, a sputtering method, or a deposition method. Preferably, a ferrocene layer is used by deposition method such as atomic layer deposition (ALD), temperature-regulated chemical vapor deposition (CVD), and more preferably by using TR-CVD (temperature-regulated chemical vapor deposition). Can be formed.

Here, when the TR-CVD is applied, the amount of iron oxide deposited on the inorganic oxide can be easily controlled by controlling the amount of ferrocene, thereby simplifying the manufacturing process of the photocatalyst and efficiently providing the photocatalyst.

Forming the ferrocene layer (S120) 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, it may be carried out at 60 ℃ to 100 ℃ in order to induce the deposition by the vaporization process of ferrocene in the application of TR-CVD.

The forming of the ferrocene layer (S120) may be performed in an air or oxygen atmosphere under atmospheric conditions, and may further include an inert gas.

Forming the ferrocene layer (S120) may form the ferrocene layer containing 0.01% to 20% by weight of ferrocene compared to the inorganic oxide.

Forming the ferrocene-derived iron oxide layer (S130) may partially or completely oxidize to iron oxide through heat treatment of the ferrocene layer and remove impurities such as carbon residues.

Forming the ferrocene-derived iron oxide layer (S130) is 50 ℃ to 900 ℃; Alternatively 100 ° C. to 800 ° C .; The temperature can be heat treated in two or more steps. For example, the step of forming the ferrocene-derived iron oxide layer (S130) includes a first heat treatment at 100 ℃ to 300 ℃ temperature and a second heat treatment at 300 ℃ to 900 ℃ temperature, each step 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 iron oxide deposition that is converted to iron oxide by the reaction of ferrocene and oxygen. The second heat treatment may be a post heat treatment after the first heat treatment, and may be an annealing process to remove impurities such as carbides to improve the activity and performance of the photocatalyst.

Hereinafter, the inorganic oxide based photocatalyst of the present invention will be described in more detail with reference to Examples and Comparative Examples.

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 It was.

More specifically, 0.02g 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, 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

Photocatalysts of iron oxide-TiO ₂ hybrid nanostructures were prepared in the same manner as in Example 1, except that 0.05 g of the iron precursor Ferrocene was applied. The iron content deposited on TiO ₂ under 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 this condition is about 1.81 wt%.

The prepared photocatalyst (Fe-TiO ₂ ) is shown in FIG. 5 by comparing transparency and color with TiO ₂ photocatalyst coated with general iron oxide.

Referring to FIG. 5, the photocatalyst (Fe-TiO ₂ ) coated with ferrocene-derived iron oxide according to the present invention is transparent and light yellow than the photocatalyst (Fe ₂ O-TiO ₂ ) coated with iron oxide (Fe ₂ O ₃ ). It can be confirmed that having.

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.

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

0.13wt% Fe-TiO ₂ 0.65wt% Fe-TiO ₂ 1.81wt% Fe-TiO ₂ BET Surface area (㎡ / 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 if the iron content of Fe-TiO ₂ is changed, the specific surface area and surface pore size does not change significantly, it can be seen that the meso pores of Fe-TiO ₂ are formed.

Evaluation Example 1

The photocatalyst (Fe-TiO ₂ ) of Example 1 was placed in a volume 3.5L batch reactor consisting of quartz glass on the top surface, the initial concentration of acetaldehyde was 66ppm, dry air (relative humidity: ˜33%, total pressure was 760 torr) and the white LED at room temperature irradiated the visible region to analyze the photodegradation characteristics of acetaldehyde. Acetaldehyde in the reactor was measured closely using gas chromatography. The results are shown in FIG.

FIG. 7 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. Referring to FIG. Photocatalyst (Fe-TiO ₂ ) prepared in the example can be seen that the photocatalytic activity of acetaldehyde by the photocatalytic activity by the visible light (white light) irradiation, the highest decomposition efficiency in visible light at 0.09 wt% ferrocene deposition amount You can see that.

In addition, as the iron content decreases, the acetaldehyde photolysis rate of Fe-TiO ₂ is faster.

Evaluation Example 2

Photocatalyst (Fe-TiO ₂ ) having a ferrocene deposition amount of 0.13 wt% was subjected to photolysis characteristics of acetaldehyde in the same manner as in Evaluation Example 1 for 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 8 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 according to the visible light irradiation time when the experiments of acetaldehyde photolysis under dry conditions and 33% humidity conditions. The graph shown.

Referring to FIG. 8, the slopes of the two graphs were similar in the same acetaldehyde concentration interval indicated by a dotted line, indicating that acetaldehyde photolysis activity was maintained similarly in visible light irradiation with or without 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.

9 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 acetaldehyde photolysis at 33% humidity. As a graph, it can be seen that high photocatalytic activity is maintained even in repeated photolysis experiments in FIG. 9.

Overall, in the present invention, TiO ₂ on which iron oxide is deposited (hereinafter, referred to as 'Fe-TiO ₂ ') was utilized for the photolysis experiment of acetaldehyde, which is one of the representative volatile organic compounds, and acetic acid of Fe-TiO ₂ according to the iron oxide content. The photolytic activity of the aldehydes 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 addition, the photocatalytic activity is generally affected by humidity, but Fe-TiO ₂ applied in the present invention showed similar catalytic activity under dry conditions and humidity conditions, and it was confirmed that the photocatalytic activity was 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 electrons and electrons for the electron / hole pair when the tiny iron oxide nanoparticles have a content of about 0.09 wt%. Reacts with water to generate radicals that quickly decompose acetaldehyde.

On the other hand, if the target organic material is not completely oxidized but partially oxidized and remains on the surface of the photocatalyst to block the active site, the activity of the photocatalyst is reduced, which is pointed out as one of the biggest problems of the photocatalyst.

However, Fe-TiO ₂ applied 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 the catalytic activity.

As a result, the concrete block 10 of the present invention can have an excellent photocatalytic activity in the visible region by applying the inorganic oxide-based photocatalyst described through the above experiment as a finishing layer, and thus excellent photolysis in various humidity and temperature environments With efficiency, it is possible to decompose environmental pollutants including volatile organic compounds, etc., as well as to have an air purification function.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

10: concrete block of the present invention
100: substrate 200: finishing layer

Claims (10)

In the concrete block containing cement, aggregate, blended water and photocatalyst powder,
The photocatalyst,
An inorganic oxide and a ferrocene-derived iron oxide layer formed on the inorganic oxide,
The ferrocene-derived iron oxide layer,
After the ferrocene layer is formed on the inorganic oxide, the ferrocene layer is oxidized to iron oxide through heat treatment of the ferrocene layer so that the iron oxide is deposited on the inorganic oxide, but the first heat treatment and the second heat treatment in which different temperatures are formed in the heat treatment. Concrete block to which the inorganic oxide-based photocatalyst is applied, characterized in that to perform step by step to remove the iron oxide and impurities are removed.
The method of claim 1,
A substrate comprising cement, aggregate, and blended water; And
And a finishing layer laminated on an upper surface of the base layer and including cement, aggregate, pigment, blended water, and photocatalyst powder.
The method of claim 2,
The photocatalyst,
In the ferrocene-derived iron oxide layer, the iron content is an inorganic oxide-based photocatalyst, characterized in that the iron content of 0.001 to 10% by weight compared to the inorganic oxide.
delete The method of claim 2,
The inorganic oxide,
Concrete block to which the inorganic oxide-based photocatalyst is applied, characterized in that it comprises at least one selected from the group consisting of oxides comprising at least one of Ti, Zn, Al and Sn.
The method of claim 2,
The inorganic oxide,
At least one selected from the group consisting of beads, powders, rods, wires, needles and fibers,
Inorganic oxide-based photocatalyst is a concrete block, characterized in that the size of the inorganic oxide is 1 nm to 500 ㎛.
The method of claim 2,
The photocatalyst,
A concrete block to which an inorganic oxide-based photocatalyst is applied, having photoactivity in a visible light region of 400 nm or more.
The method of claim 2,
The photocatalyst,
A concrete block to which an inorganic oxide-based photocatalyst is applied, characterized in that it has photoactivity under dry conditions of 30% or more humidity.
The method of claim 2,
The ferrocene-derived iron oxide,
Concrete block to which an inorganic oxide-based photocatalyst is applied, comprising at least one of compounds represented by the following Chemical Formula 1.
[Formula 1]
Fe _X O _Y H _Z
(X, Y and Z are each selected from 0 to 3 and X and Y are not zero.)
The method of claim 2,
The photocatalyst,
Concrete block with an inorganic oxide-based photocatalyst, characterized in that the specific surface area is more than 5 (㎡ / g), the average pore size is 50nm or less.

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