KR101605042B1 - Manufacturing method of having visible light-responsive photocatalyst ability clay brick and clay brick thereof method - Google Patents

Abstract

The present invention relates to a clay brick having a visible light-responsive photocatalyst function and used largely as a brick for construction, and a method for manufacturing the same. More particularly, the present invention relates to a clay brick having a photocatalyst function. The clay brick uses a highly active photocatalyst agent showing a photocatalyst function even in the visible light region so that the function of a clay brick used for construction or interior decoration may be improved. In addition, the clay brick is one having excellent aesthetic properties by virtue of various colors to allow multi-color interior designs to be expressed. A ternary photocatalyst including copper-supported tungsten oxide and titanium peroxide is fixed to the surface of the clay brick as a photocatalyst agent has been issued recently and having a visible light-responsive function, and thus the clay brick has a decomposition function capable of adsorbing and decomposing harmful volatile organic compounds and enables removal of contaminants through redox reaction caused by the surface-exposed photocatalyst particles. The clay brick uses, as a binder, smectite prepared to have a composition similar to the composition of the starting materials of the clay brick and to show high transparency and higher viscosity as compared to natural clay. Thus, it is possible to maintain the functions of the clay brick itself, including far infrared ray emission and anion emission features.

Description

[0001] The present invention relates to a clay brick having a photocatalytic function of visible light response and a clay brick produced by the method. [0002]

The present invention relates to a method for producing a clay brick having a photocatalytic function, which is mainly used as a building brick, and a clay brick produced by the method. More particularly, the clay brick has a photocatalytic function. It is a clay brick with excellent aesthetics that can improve the function of clay bricks used for construction and interior decoration by the highly active photocatalyst and can pursue interior design of various colors by clay bricks of various colors. A photocatalyst that has become an issue and has a visible light responsive function, a decomposition function capable of adsorbing and decomposing harmful volatile organic compounds by immobilizing a three-component photocatalyst of tungsten oxide and titanium peroxide on a clay brick surface, The pollutants are removed by the redox reaction by the photocatalyst particles. It is possible to remove the clay brick by using the sparate as a binder of the photocatalyst so as to have a composition similar to that of the starting material of the clay brick and having a high transparency and exhibiting a binder performance superior to natural clay. A method and a method for producing a clay brick having a photocatalytic function capable of maintaining a visible light response on a surface of a clay brick without deteriorating the absorption of light by transparency without deterioration of far-infrared radiation and anion emission. To a clay brick.

The function of clay bricks is to provide the residential space of people from the aspect of supporting the load of the building as the material of the building or the press, or the aesthetic view for the landscape, And serves as a human-friendly packaging material that gives a sense of stability.

These clay bricks have traditionally been regarded as fulfilling their roles primarily as structural and visual roles, but as clusters have changed and people's perceptions have shifted, clay bricks have become more important in their functional aspects. The clay bricks of Korea increased exponentially from the Saemaul Movement in the 1970s, but most of the houses and low-rise buildings were constructed by clay bricks. If clay bricks so far have been used with a focus on patterns and masonry methods in terms of visual aspects, clay bricks, which have been most recently attracted attention, are obtained by artificially suppressing the volatilization of carbon in the clay bricks and depositing them on the brick surface And has been pursuing such changes as giving a visual stability by processing the colored clay bricks and the angled portions which are ring-shaped and rounded.

 Until recently, the clay brick market has been dominated by various shapes and patterns in consideration of the existing visual function and structural properties. However, the cement block using cement as a binder is designed to provide a more comfortable feel through surface processing. The market has been encroached, and currently clay bricks are being installed only in some parks and apartments. Another use of clay bricks has been used for interior and exterior interiors with the exterior facing the exterior and interior walls of buildings. However, recently, the development of glazed bricks and the development of manufacturing methods have led to the production of clay bricks with multi- And low-level commercial districts.

 Clay bricks have been under pressure for new functions to maintain the clay brick market through such transitions, prime and decay periods, and some researchers have introduced patents that use photocatalytic titanium dioxide photocatalysts by some researchers.

The clay brick material with the above-mentioned optical function has a problem that it can be used when the sunlight or ultraviolet ray is strong. That is, Patent No. 1070854 relates to an interior and exterior material coated with apatite-coated titanium dioxide photocatalyst on a clay product. In summary, Na ⁺ 213 mmol (mM), K ⁺ 7.5 mmol (mM) Ca ^{2 +} 50 millimoles (mM), Mg ^{2 +} 1.5 millimoles (mM), Cl ^- 147.8 millimoles (mM), HCO ₃ ^- 6 millimoles (mM), HPO ₄ ^- 12 millimoles (mM), SO ₄ ^2- 0.75 mmol (mM) was dissolved, and 50 g of photocatalyst TiO ₂ on the nanoparticles was added while stirring at high speed. The mixture was agitated for one hour so that the apatite could be uniformly positioned on the surface of the photocatalytic TiO _{2. The} mixture was stirred for 24 to 48 hours The obtained apatite was grown and heated at a temperature of 200 to 300 ° C for 30 to 90 minutes to obtain a titanium dioxide photocatalyst coated with stabilized apatite on its surface. A titanium dioxide photocatalyst having an apatite surface bonded to 1 to 19 wt% To 19% by weight of a stabilizer and 1 to 19% by weight of a stabilizer, In contrast, a water-based paint containing a titanium dioxide photocatalyst bonded to the surface of apatite is obtained, and a water-based paint is applied to the inside and the outside of the clay material by dipping, spray coating, dip coating or roller coating to remove harmful organic compounds And the like are adsorbed and decomposed to purify the indoor and outdoor environments.

However, since this technology is coated with apatite on the surface of the titanium dioxide photocatalyst, it is noted that the titanium dioxide photocatalyst is inhibited by the photocatalytic action of the photocatalyst rather than the visible light-responsive photocatalyst There is a problem that it can not be done. In addition, since indoor space is limited to adsorbing harmful gas by apatite rather than photocatalytic function, adsorption can not be made indefinite unless photodegradation occurs after adsorption, and there is a problem that the function is lost after a certain period of time.

In some cases, titanium dioxide photocatalyst powder was mixed in the manufacturing process of the clay product to produce the product. However, due to the characteristics of the clay product formed at high temperature, the titanium dioxide hardly functions as a photocatalyst, .

       Japanese Patent No. 1081908 discloses a method for producing a mixed powder comprising mixing 30 to 60 wt% of clay, 30 to 65 wt% of clay, 3 to 8 wt% of feldspar, manganese oxide or iron oxide of 2 to 3 wt%

A kneading step of adding water to the mixed powder so as to have a water content of 16 to 18% by weight and kneading;

A molding step of extruding the kneaded dough by a kneader to form a molded body;

Forming an antibacterial glaze by mixing 85 to 95% by weight of clay glaze, 1 to 5% by weight of boric acid, 1 to 5% by weight of shell powder, and 1 to 5% by weight of titanium oxide sol;

An antibacterial treatment step of treating the molded body with an antibacterial glaze mixed with boric acid, titanium oxide sol, and shell powder;

A drying step in which the molded article treated or applied with the antibacterial glaze is dried at 20 to 120 DEG C for 36 to 48 hours;

And a sintering step of placing the dried formed body in an automatic tunnel kiln and sintering the sintered body at 30 to 1250 DEG C for 30 to 40 hours.

       However, the problem with this patented technique is that titanium oxide sol which exhibits antibacterial property is expressed when it is in the form of anatase to exhibit photocatalytic function. When titanium oxide is exposed at a temperature of 800 ° C or higher, anatase- There is a problem that only a function as a pigment can be exerted.

Patent No. 0410149 uses nitrogen oxide (NOx) to purify nitrogen oxide (NOx) by decomposing surrounding harmful substances when exposed to sunlight, which is a characteristic of titanium dioxide (TiO ₂ ) And a method for producing clay bricks made of environmentally friendly building bricks and floor bricks by mixing titanium dioxide (TiO ₂ ), which is a photocatalyst material having an effect of decomposing pollutants and blocking ultraviolet rays, into the main raw materials of clay products. In other words, 90 to 98% of the main raw materials of the photocatalytic clay brick and clay products, which is characterized in that the titanium dioxide (TiO ₂ ) as a photocatalyst material is contained at a weight ratio of 2 to 10% Powder of titanium dioxide (TiO ₂ ), which is a photocatalyst material, is added at a blending ratio of 2 to 10%, molded by a vacuum injector, dried at a temperature of 50 to 100 ° C for 50 to 60 hours and then heated at a temperature of 1,100 to 1,160 ° C To 30 to 40 times a pre-heating and a sintering-cooling process. The above patent discloses a clay brick which uses titanium dioxide as a photocatalyst and fires at a high temperature of 800 ° C or higher and exhibits a photocatalytic function. However, since titanium dioxide has a crystal transition at a high temperature The photocatalytic function can not be expected because it happens, and this fact is a knowledge which is common knowledge in the whole science, and it is well known that the clay brick can not emit a photocatalytic function.

Patent No. 0840571 relates to a clay brick manufacturing method and a functional clay brick using a zinc oxide photocatalyst, which comprises mixing 30 to 60 wt% of clay, 30 to 65 wt% of clay, 2 to 3 wt% of manganese oxide or iron oxide, A kneading step of adding water to the mixed powder so as to have a water content of 16 to 18% by weight and kneading the kneaded kneaded kneaded product; a preliminary molding step of extruding the kneaded kneaded product by a kneader to form a molded article; A molding step consisting of steps;

Producing a coating mixture in which 150 to 400 parts by weight of a zinc salt aqueous solution is mixed with 100 parts by weight of bentonite;

A coating step of coating the coating mixture on the surface of the molded body to a thickness of 1 to 5 占 퐉 and coating the coating mixture;

A cutting step of cutting the molded body coated with the coating mixture into a brick shape by a cutting machine;

Drying the cut brick at a temperature of 20 to 120 ° C for 36 to 48 hours;

Wherein the dried bricks are placed in an automatic firing furnace and preheated at 700 to 900 DEG C for 5 to 15 hours and then fired at 1100 to 1250 DEG C for 24 to 36 hours to produce a clay brick using the zinc oxide photocatalyst will be.

The above patent uses ZnO (zinc oxide) as a photocatalyst material among various oxides capable of exhibiting a photocatalytic function, and zinc oxide photocatalyst is one of excellent photocatalytic materials exhibiting a band gap similar to titanium dioxide photocatalyst, but in contact with water or water There is a problem in that it is dissolved. Further heat treatment to the coating since the transition to the spinel materials such as oxides of zinc oxide is clay materials and as a zinc oxide melting When heat-treated at more than 1,100 ℃ hot clay components, one of SiO ₂ and a reaction sintering ZnSiO ₄ of The product shall be manufactured at a low temperature (below 1,000 ℃) that does not react with the viscous materials. On the other hand, clay bricks are required to be heat treated at about 1,200 ° C in order to exhibit high compressive strength and low water absorption, and sintering at low temperatures can not achieve this. The content of the patent is easily understood by those engaged in the field of ceramic sintering. Particularly, in Patent Document No. 0602728, when zinc oxide is added to clay mined mine residue, a clay sintered body having a low water absorption of about 1% at a temperature of 1000 to 1100 can be produced, and zinc oxide acts as a flux, The sludge can be sintered at a low temperature. Therefore, at high temperature, zinc oxide binds to clay minerals, and thus the photocatalytic function is lost.

In view of the above circumstances, it is an object of the present invention to provide a clay brick having a photocatalytic function in response to a visible light and a method of manufacturing the clay brick, In order to improve the visible light region, a mixed material of tungsten oxide and titanium peroxide with metal ions was used as a photocatalyst, and a transparent artificial clay having a high thixotropy was used as a binder for efficiently dispersing the photocatalyst. An organic dispersant or thickener The clay brick was coated with a uniformly dispersed coating on the surface of the clay brick. The clay brick was made of materials considering the environmental aspect, energy aspect, and economical efficiency. In other words, all raw materials are supplied within a radius of 30km, so it is distinguished from other companies paying transportation costs up to 25,000 won / ton, and current energy conservation is urgent and consumes a large amount of resources. Thereby reducing the natural resource consumption and lowering the firing temperature of the clay bricks through the carbon components contained in the waste itself.

 In the present invention, 60% by weight of clay, kaolinite and feldspar are used as the raw material of clay bricks, and 40% by weight of fly ash generated from a thermal power plant is used. The sustainability of the construction and operation of the thermal power plant is due to the various problems of nuclear power generation, the change of international oil prices, the establishment of high energy consumption culture due to economic development, and the abnormal temperature phenomenon caused by climate change. This is expected to continue in the future as it is expected to be consumed, and additional construction of cogeneration power plants is scheduled. It will come time to consider seriously consideration of the waste treatment methods associated with energy shortage. Accordingly, the present invention is a method of effectively utilizing coal ash, which has an enormous amount, and the coal ash having a chemical composition similar to that of clay is used as an additive of clay bricks. Further, the heat of the unburned carbon is about 2000 kcal, 50 to 100 ° C lowering energy and resource consumption. The clay bricks produced by using these raw materials are supported on a suspension of artificial clay (slim tite) in which tungsten oxide-titanium peroxide on which metal ions are loaded is dispersed or the suspension is uniformly applied by using a spray or a roller The present invention provides a clay brick manufacturing method having a visible light photocatalytic function.

The photocatalytic performance is such that organic pollutants such as NOx, SOx, and other non-point pollutants generated from automobiles and factories from the outside are decomposed by the photocatalytic oxidation and reduction action of sunlight under the sunlight. In the indoor environment, volatile organic compounds It is an object of the present invention to provide a clay brick having a photocatalytic function in response to a visible light, which has a function of decomposing a compound by redox action using fluorescent light or indoor illumination such as LED.

The clay brick manufacturing method having the photocatalytic function of the visible light response type of the present invention

(1) preparing a photocatalyst mixed with tungsten oxide and titanium peroxide on which copper oxide is supported;

(2) mixing 20 to 40% by weight of clay, 10 to 20% by weight of kaolin, 1 to 10% by weight of feldspar, and 40 to 50% by weight of fly ash;

(3) adding water to the mixture to knead the mixture so as to have a water content of 17 to 22%;

(4) extruding the kneaded material from a brick mold;

(5) drying the molded product at a temperature of 80 to 200 ° C for 36 to 48 hours;

(6) firing the dried shaped material at a temperature of 1,100 to 1,200 ° C for 24 to 36 hours and then cooling;

(7) 90 to 99% by weight of artificial clay binder prepared by dispersing 1 to 5% by weight of Smackite in 95 to 99% by weight of water is mixed with 1-10% by weight of the photocatalyst in a homogenizer at 11,000 rpm for 10 minutes Preparing a coating agent;

(8) applying the coating agent to the surface of the cooled mold with a low-pressure spray;

(9) drying the molded article coated with the coating agent at a temperature ranging from room temperature to 250 ° C.

Another aspect of the present invention is a clay brick having a photocatalytic function in response to visible light, which is manufactured by the above-described method.

 The clay brick having the photocatalytic function of the visible light-responsive photocatalyst produced by the production method of the present invention exhibits photocatalytic function in the region of ultraviolet rays and visible light, so that not only the harmful volatile organic compounds in the room are purified, but also NOx, SOx It is possible to provide a clean product at all times by self-crying action from removing harmful gas and decomposing and removing pollutants.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart of a process for producing a clay brick having a photocatalytic function in response to a visible light according to the present invention
Figure 2 is a graph showing the measurements of the degradability of methylene blue under UV-A shown in Table 1 of the present invention
3 is a graph showing measured values of decomposition ability of methylene blue under a fluorescent lamp (visible light) shown in Table 2 of the present invention
4 is an electron micrograph of a photocatalyst prepared according to Example 1 of the present invention
5 is a graph showing the acetaldehyde removal rate measurement values shown in Table 3 of the present invention
6 is a photograph of a binder solution prepared by the method of producing a clay brick having a photocatalytic function of visible light response according to the present invention

Hereinafter, a method for producing a clay brick having a photocatalytic function in response to a visible light according to the present invention will be described with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart illustrating a process for producing a clay brick having a photocatalytic function in response to a visible light according to the present invention.

As shown in FIG. 1, the clay brick having a photocatalytic function in response to a visible light according to the present invention,

(1) preparing a photocatalyst mixed with tungsten oxide and titanium peroxide on which a transition metal oxide is supported;

(2) mixing 20 to 40% by weight of clay, 10 to 20% by weight of kaolin, 1 to 10% by weight of feldspar, and 40 to 50% by weight of fly ash;

(3) adding water to the mixture to knead the mixture so as to have a water content of 17 to 22%;

(4) extruding the kneaded material from a brick mold;

(5) drying the molded product at a temperature of 80 to 200 ° C for 36 to 48 hours;

(6) firing the dried shaped material at a temperature of 1,100 to 1,200 ° C for 24 to 36 hours and then cooling;

(7) 90 to 99% by weight of artificial clay binder prepared by dispersing 1 to 5% by weight of Smackite in 95 to 99% by weight of water is mixed with 1-10% by weight of the photocatalyst in a homogenizer at 11,000 rpm for 10 minutes Preparing a coating agent;

(8) applying the coating agent to the surface of the cooled mold with a low-pressure spray;

(9) drying the molded article coated with the coating agent at a temperature ranging from room temperature to 250 ° C.

In the step (1), titanium oxysulfate (1.0 mol), tungstic chloride (1.0 mol), transition metal salt (0.05 mol) and ammonium carbamate (2.5 mol) were weighed, Stirring and dissolving (S10)

The titanium oxyhydroxide aqueous solution and the tungsten chloride aqueous solution are stirred at 250 rpm in a stirrer and heated to maintain the reaction temperature at 80 ° C.

Injecting ammonium carbamate into the heated titanium oxysulfate aqueous solution to produce a titanium precursor (S30)

Injecting ammonium carbamate into the heated tungsten chloride aqueous solution to form a tungsten precursor; injecting the transition metal salt solution continuously at the time of completion of the injection to form a transition metal precursor on and around the tungsten precursor particle; (S40)

(S50) a step of obtaining a transition metal-supported tungsten precursor and a titanium dioxide precursor on the cake by filtering the titanium precursor and the tungsten precursor where the transition metal precursor is formed on and around the particle and then washing with ammonia water and distilled water;

Heating the tungsten precursor carrying the transition metal precursor on the cake to 500 ° C for 1 hour to crystallize it as an oxide and drying the resulting powder of titanium dioxide precursor on the cake under reduced pressure at 70 ° C to obtain a powder;

The transition metal oxide-supported tungsten oxide is mixed with 5 to 95% by weight of tungsten oxide and 5 to 95% by weight of titanium dioxide powder with 80 to 90% by weight of hydrogen peroxide to 10 to 20% Tungsten, and titanium peroxide (step S70).

Further, in step (S30), ammonium carbamate is injected into the heated aqueous solution of titanium oxysulfate at a fixed position at an injection rate of 50 ml / min, and the injection is stopped when the pH value of the aqueous solution of titanium oxysulfate is 7.0 .

In step (S40), ammonium carbamate is injected into the heated aqueous tungsten chloride solution at a fixed rate of 50 ml / min. When the pH value of the aqueous tungsten chloride solution reaches 7.0, the injection is stopped to remove the tungsten precursor And continuously injecting the transition metal salt aqueous solution at an injection rate of 50 ml / min at the time when the injection is completed.

In addition, the step (S70) is characterized in that the mixture is put into a zirconia ball-mill and then pulverized, mixed and crystallized in a cycle of running for 5 minutes at a rotation speed of 1,100 rpm for 3 hours and for 1 minute at a high energy speed ball mill.

Further, the titanium dioxide precursor is characterized by being composed of an amorphous titanium dioxide, an anatase and a rutile mixed phase.

The transition metal salt may be at least one selected from the group consisting of Pt salt, Au salt, Ag salt, Pd salt, Fe salt, Nb, Ru salt, Ir salt, Rh salt, Co salt, Bi salt and Cu salt.

Another aspect of the present invention is a clay brick having a photocatalytic function in response to a visible light produced by the above-described method.

Before describing the present invention in detail, the transition metal salt supported on tungsten oxide may be at least one selected from the group consisting of Pt salt, Au salt, Ag salt, Pd salt, Fe salt, Nb, Ru salt, Ir salt, Rh salt, A salt, and a Cu salt. However, throughout the description, the Cu salt will be limited to representatives.

More specifically, the clay brick is composed of 50 to 60 wt% of clay, kaolin and feldspar, and 40 to 50 wt% of coal fly ash produced from a thermal power plant. The composition of the clay brick is not particularly limited. The clay may be a general plastic clay, a woody clay, a clay clay, a red clay soil, a black clay soil, and kaolin may be a viscous kaolin and a kaolin kaolin. Feldspar can also be any feldspar used in clay bricks in general. Fly ash generated from a thermal power plant should contain at least 10% of the unburned coal that can generate heat of 2,000 kcal or more. Generally, coal fly ash which is used as cement admixture can not be used.

The process for producing clay bricks comprises uniformly mixing 10 to 20% by weight of kaolin, 20 to 40% by weight of clay and 1 to 10% by weight of feldspar with 40 to 50% by weight of fly ash in weight percent; Molding the uniformly mixed mixture into a vacuum injection molding machine at a moisture content of 17 to 22%; Drying the molded product at 80 to 200 ° C for 36 to 48 hours, then calcining the molded product at a temperature of 1,100 to 1,200 ° C for 24 to 36 hours, and cooling the molded product.

        The coating agent composed of the photocatalyst agent and the binder is constituted as a transparent artificial clay binder and a three-component photocatalyst of copper oxide-supported tungsten oxide composite, titanium peroxide. The composition ratio ranges from 1 to 10% by weight of the photocatalyst and 90 to 99% by weight of the binder. When the photocatalyst is less than the above range, the efficiency as a photocatalyst is lowered, and if it exceeds this range, economical efficiency deteriorates and the function as a binder deteriorates.

     In tungsten oxide supporting copper oxide, copper oxide was used as the auxiliary catalyst for supporting the photocatalyst. As the photocatalyst, a tungsten oxide composite containing copper oxide was used as a basic photocatalyst material, and a titanium compound was used as a subsidiary material. In particular, the raw material is not limited to the main raw material, and the raw material and the auxiliary raw material may be changed depending on the lighting condition of the room. The copper oxide-supported tungsten oxide composite has recently been shown to exhibit a high photocatalytic activity in the visible light region, and was also used as a main raw material for the photocatalyst in the present invention. Copper, which is a metal, was also used to increase the redox efficiency by retarding charge recombination at the time of photoexcitation of tungsten oxide. The metal salt material for the subsidiary catalyst supported on the tungsten oxide photocatalyst is not limited to the copper salt but may be selected from the group consisting of Pt salt, Au salt, Ag salt, Pd salt, Fe salt, Nb salt, Ru salt, Ir salt, , A Bi salt, and more preferably a Cu salt, a Pt salt, an Au salt, a Pd salt, or the like.

        In addition, the coexistence of the titanium compound photocatalyst and the tungsten oxide photocatalyst is intended to enhance the charge separation efficiency (effectively supplying holes to titanium oxide) at the time of photoexcitation, thereby maximizing the redox potential of the photocatalyst, thereby exhibiting superhydrophilicity in the visible region.

        The photocatalyst is used in an amount of 5 to 95% by weight, based on 100 parts by weight of tungsten oxide, of titanium oxide per 5 to 95% by weight of copper oxide-supported tungsten oxide composite comprising 0.5 to 5 parts by weight of copper. If the use range is exceeded, there arises a problem that the visible light response efficiency is lowered.

      The photocatalyst is not particularly limited, but in the present invention, commercially available reagent grade raw materials may be used together with the raw materials synthesized by the inventors of the present invention.

      First, the photocatalyst used by the synthesis was prepared by the following method.

Tungsten compounds containing copper metal ions (copper nitrate, copper chloride, copper sulfate, copper bromide, copper iodide, copper ammonium chloride, copper carbonate, copper citrate, copper phosphate and the like) and tungsten metal ions , Tungstic acid, tungsten alkoxide, tungsten chloride, tungsten nitride, tungsten sulphide, etc. It is preferable to use ammonium metatungsten which is soluble in water and easily rinsed) (mol / L) and 1.0 M, and this was dissolved in distilled water. Ammonium carbamate was used as a precipitant and dissolved in distilled water. The solution in which tungsten metal ions were dissolved was introduced into a round bottom flask, and stirred at a speed of 250 rpm using a propeller stirrer to prevent a concentration gradient from occurring. The concentration of the precipitant at room temperature such as ammonium carbamate is preferably 1.3 times or more the over concentration for the high yield of the substance to be precipitated. Therefore, in order to obtain a yield close to 100%, 2.5M (mol / L) And used. The room temperature precipitant was injected into a round bottom flask at a constant rate of 50 ml / min using an injection method, and the nucleation principle was heterogeneous nucleation. Therefore, after the tungsten salt forms a precursor by a room temperature precipitant, To allow the copper ions to be supported on the tungsten precursor. Precipitation and crystallization proceeded in a temperature range of 40 to 100 캜 to obtain a precursor in which copper and tungsten were mixed. The precursor of the obtained copper and tungsten composite was subjected to heat treatment in an oxidizing atmosphere of 400 to 550 ° C in an electric furnace to form crystals of copper oxide and tungsten oxide. This was used as the main ingredient of the photocatalyst.

      In addition, tungsten oxide coated with copper oxide may be prepared by grinding commercialized tungsten oxide and copper precursor using a high energy speed ball mill, and then heat-treating the copper precursor at 500 ° C in an electric furnace. It is also possible to disperse the tungsten oxide and the copper precursor in water containing methanol or the like and irradiate ultraviolet rays or visible light thereto to carry the metal component. In the case of irradiating light of a wavelength that can be photoexcited by tungsten oxide, the precursor is reduced by electrons generated by photoexcitation and is supported on the surface of tungsten oxide particles as a metal. Preferably, however, it is better to carry a synthesized copper precursor on a tungsten precursor, which is advantageous for controlling the size of the particles in the precursor stage and for enhancing the photoactivity during the pulverization and activation process, and heating them.

      The titanium dioxide precursor was prepared by the room temperature precipitation method described above. The titanium salt used for producing titanium dioxide is prepared by dissolving titanium oxysulfate, titanium tetrachloride, titanium oxynitrate, titanium tetraethoxide, titanium tetra n butoxide, titanium tetraisopropoxide, etc. in water, alcohols, , And titanium oxy sulfate is preferably dissolved in water to be used. Titanium oxysulfate can obtain spherical titanium dioxide nanosized by a sulfuric acid group, and it is easier to remove the sulfate group from the precursor produced under chloride than the process for removing the sulfate group in the process of obtaining the titanium dioxide precursor, The toxicity such as the generation of chlorine gas is low. However, it does not specifically restrict starting materials.

In the present invention, the synthesis conditions are determined by fixing the precursor at a reaction temperature range in which a hydroxide and a crystalline material can be simultaneously produced by changing the reaction temperature only in the presence of various reaction factors in the synthesis process of the precursor by the room temperature precipitation method. A precursor in the form of amorphous hydroxide and crystalline titanium oxide coexisted was obtained by changing the reaction temperature in the range of 40 to 100 ° C. Especially, at the reaction temperature of 80 ℃, the amount of amorphous hydroxide was decreased, and the crystallinity of anatase and rutile mixed phase was high. The amount of titanium dioxide which can exhibit a substantial photocatalytic function has increased, and it is preferable that anatase-type crystals and rutile-type crystals are mixed in order to increase the photocatalytic activity of titanium dioxide. In this condition, desired results can be obtained. Since such a mixed phase precursor reduces the height of the activation energy required for the crystal transition, it becomes easy to induce secondary reactions such as crystallization, defects and substitution of hydroxides and salts. It can be clearly seen that this is completely different from the result obtained by synthesizing titanium dioxide from alkoxide or titanium salt in the conventional production of titanium dioxide and obtaining anatase-type titanium dioxide by heat treatment at 600 ° C or higher for crystallization.

That is, the titanium dioxide precursor composed of the anatase and rutile crystal phase and the amorphous phase mixed phase can be changed to a material exhibiting photocatalytic activity at a high temperature of 600 ° C or higher without conducting a heat treatment process. However, since the crystallinity of anatase and rutile phase obtained by this method is not higher than that of titanium dioxide heat-treated at a temperature of 600 ° C or higher and amorphous particles still exist, the photocatalytic activity in the visible light region and the high photocatalytic activity in the ultraviolet region I can not expect it. Therefore, it is necessary to increase the degree of crystallinity in order to exhibit such high activity and photocatalytic function in the visible region. Accordingly, the present invention aims to solve this problem by using a high-energy speed ball mill capable of uniformly blending the precursor, and grinding to expand the specific surface area.

      On the other hand, the starting material of the photocatalyst is not limited in the present invention. In addition to using synthetic titanium dioxide as a source material for the synthetic titanium dioxide photocatalyst, commercially available titanium dioxide (anatase or anatase rutile mixed phase) photocatalyst can be purchased and used, and anatase alone and titanium dioxide in the form of anatase and rutile are mixed with copper It is also possible to produce a photocatalyst capable of exhibiting a photocatalytic function under visible light by mixing with supported tungsten oxide or the like and activating it with a high energy speed ball mill.

A high energy speed ball mill (model: Pulverisette 7 premium line) is capable of high-speed rotation of 1,100 rpm. The container is made of zirconium dioxide and has a capacity of 80 ml. In order to prevent impurities from entering, And 50 g of a ZrO ₂ 3 mm ball having a high hardness were added to the reaction mixture, and anhydrous alcohol and hydrogen peroxide solution were used as the solvent used. Since the low-revolving ball mills to be used are intended for mixing rather than the purpose of grinding, 300 rpm can be sufficiently effective, and the higher the number of revolutions is 600 rpm, the lower the grinding efficiency and the higher the efficiency On the other hand, the high energy speed ball mill used in the present invention can be up to 1,100 rpm, The internal temperature rises up to 100 ~ 150 ℃ due to internal friction and collision, and up to 5 ~ 10 atm pressure in case of wet mixing. The characteristics of this device are the hydrothermal synthesis process of titanium dioxide (125 ℃, And the amorphous phase becomes an anatase crystal phase by heating for 3 hours).

       The copper oxide-carrying tungsten oxide and the titanium dioxide precursor were mixed at a predetermined ratio, and hydrogen peroxide solution was used as a solvent for 5 minutes, and the reaction was carried out for 3 hours in a cycle of stopping for 1 minute. The composition of the titanium dioxide precursor reacts with the hydrogen peroxide under the pulverization and mixing of the photocatalyst for 3 hours, and the amorphous phase and the anatase and rutile mixed phase in the titanium dioxide precursor undergo crystallization with titanium peroxide containing a peroxy group of crystallization, The photocatalytic agent capable of manifesting a visible light responsive photocatalytic function with a particle size of 50-100 nanoparticles of copper supported tungsten oxide and titanium peroxide is manufactured. These results are attributable to the internal temperature rise of about 150 ° C caused by the high-speed spinning of the high-energy speed ball mill and the vapor pressure generated therefrom, which transforms the amorphous particles into crystals and uniformly mixes and crushes the photocatalyst raw materials, And to provide energy so that the characteristics can be efficiently expressed. This is due to the similar effect to the principle of hydrothermal synthesis, which is widely known as titanium dioxide ultraviolet photocatalyst production method.

      In the present invention, the binder used for fixing the photocatalyst to clay bricks is artificial clay. The artificial clay may be smacktite, mica, kaolinite or the like. More preferably, since the binder has to maintain transparency when mixed with the photocatalyst, it is preferable that the synthetic smacktite can exhibit the transparency when dispersed in water. Clay binders should exhibit thixotropy (a phenomenon in which the strength is lowered if the clay is continuously crushed into water, but the strength is restored if left untouched), and the thixotropic phenomenon is expressed in natural clays, It can not be used because it can not show the translucency.

The reason why transparency and transparency must be secured is that when the photocatalyst is mixed with a binder, the light reaches the photocatalyst through the binder to react with oxidation and reduction, Clms Page number 3 > of clay can not ensure transparency and transparency, and can be coated on a photocatalyst, thereby deteriorating photocatalytic efficiency. It is not necessary to use binders as clay materials, but artificial clay has the same composition as clay bricks. It is also possible to block water penetration in addition to water affinity. This is because the natural bentonite is the same as that used in the field of geosynthesis. It has a layered structure and has a characteristic of adsorbing noxious gas components and is different from some transparent inorganic binders (silicate). A representative example of the inorganic binder is sodium silicate or silicate, which is referred to as water glass. However, it has very high alkalinity. In order to dry it, it has to be dried at a temperature of 120 ° C or more for a long time. When it is exposed to water for a long time, have. In addition, inorganic binders prepared by modifying alkoxides and the like are very expensive and, therefore, there is a problem in that they are not economically suitable for use in very general products such as clay bricks.

Preferably, the artificial clay binder is used by dispersing 1 to 5% by weight of smacktite in 95 to 99% by weight of water. Outside this range, there is a problem that the bonding force as a binder is lowered or the transmittance is lost. The use of more preferable smacktite is to use 2% by weight.

Hereinafter, an embodiment of the clay brick manufacturing method having the photocatalytic function of the visible light response type photocatalyst according to the present invention will be described as follows.

[Example 1]

Copper-supported tungsten oxide and titanium peroxide mixed photocatalyst preparation

(Mol) of titanium oxysulfate, 1.0M (mol) of tungsten chloride, 0.05M (mol) of copper chloride, and 2.5M (mol) of ammonium carbamate were weighed out and dissolved in 1L of water,

 The aqueous solution of titanium oxysulfate and the aqueous solution of tungstic chloride were each stirred at 250 rpm in a stirrer and heated to maintain the reaction temperature at 80 ° C.,

 In the reactor, ammonium carbamate was injected into the heated aqueous solution of titanium oxysulfate at a fixed rate of 50 ml / min. When the pH of the aqueous solution of titanium oxysulfate was 7.0, the injection was stopped to generate a titanium precursor,

 In another reactor, ammonium carbamate was injected into the aqueous solution of tungstic chloride heated to 80 ° C at a fixed rate of 50 ml / min and stopped at the point where the pH value of the aqueous tungstic chloride solution reached 7.0 to generate a tungsten precursor And continuously injecting a copper chloride aqueous solution at an injection rate of 50 ml / min to produce a copper precursor on and around the tungsten precursor particle,

 The titanium precursor and the tungsten complex precursor where the copper precursor was formed on and around the particle were respectively filtered and then washed with ammonia water and distilled water until the point where no chlorine ion and sulfate ion were detected to obtain a precursor on the cake (a copper precursor supporting tungsten precursor, Titanium dioxide precursors (amorphous titanium dioxide, anatase and rutile mixed phase)

 The tungsten precursor carrying the copper precursor on the cake was heated at 500 ° C for 1 hour to crystallize it as an oxide and the resulting titanium dioxide precursor on the cake was dried under reduced pressure at 70 ° C to obtain a powder,

 20 wt% of hydrogen peroxide was weighed in a zirconia ball mill container to 80 wt% of a powder mixture composed of 95 wt% of copper oxide-supported tungsten oxide, 5 wt% of amorphous titanium dioxide on the cake and 5 wt% of titanium dioxide powder on the anatase rutile mixed phase, The insufficient water was added by adding anhydrous alcohol, followed by pulverizing, mixing and crystallizing the mixture at a cycle of running for 5 minutes at a revolution speed of 1,100 rpm of a high energy speed ball mill for 3 hours and stopping for 1 minute to obtain a tungsten oxide / Titanium peroxide photocatalyst.

Manufacture of clay brick moldings

20 to 40% by weight of clay, 10 to 20% by weight of kaolin and 1 to 10% by weight of feldspar are added to and mixed with 40 to 50% by weight of fly ash,

Water is added to the mixture to knead the mixture so that the water content of the clay mixture becomes 17 to 22%

The kneaded material was extruded into a brick mold which had been shaped using a vacuum injection kneader,

The molded product is dried at a temperature of 80 to 200 캜 for 36 to 48 hours,

The dried shaped material is calcined at a temperature of 1,100 to 1,200 ° C. for 24 to 36 hours and then cooled to produce a clay brick molding.

Manufacture of artificial clay binders

Since the photocatalyst has no self-bonding force, it is necessary to use a binder for binder, and using a material similar to that of the clay brick can exhibit a new function without losing the inherent properties of the clay brick. The binder of the clay brick and the photocatalyst agent is preferably an artificial clay having transparency when it is dispersed in water. The binder for immobilizing the photocatalyst agent on the surface of the clay brick is a synthetic spha mate (or montmorillonite Is also dispersed in 98% by weight of water so as to have a content of 2% by weight to prepare an artificial clay binder.

Photocatalytic clay brick manufacture with visible light response

5% by weight of the photocatalyst was mixed with 95% by weight of artificial clay binder having 2% dispersed therein, and the resulting mixture was dispersed and mixed for 10 minutes using a homogenizer (HOMO MIXER, 11,000 rpm)

The coating agent is applied to the surface of the clay brick mold using a low-pressure sprayer,

The clay brick molding coated with the coating agent is naturally dried at room temperature or dried at 250 ° C and then packed to complete the manufacture of a clay brick having a photocatalytic function as a visible light-responsive photocatalyst.

[Example 2]

In the same manner as in Example 1, 5 wt% of copper oxide-supported tungsten oxide and 95 wt% of titanium dioxide were changed.

[Example 3]

The procedure of Example 1 was repeated except that tungsten oxide on which copper oxide was supported was changed to 50 wt% and titanium dioxide was changed to 50 wt%.

[Example 4]

The procedure of Example 1 was followed except that the metal salt for gold nanoparticles was changed to Pd salt.

[Example 5]

The procedure of Example 1 was repeated except that the metal salt for gold nanoparticles was changed to Pt salt.

[Example 6]

The process for preparing copper oxide-carrying tungsten oxide and titanium peroxide in Example 1 was omitted, and copper oxide, tungsten oxide, and titanium dioxide were changed to common copper.

[Comparative Example 1]

The photocatalyst prepared by the synthesis in Example 1 was discharged, and p-25 titanium dioxide of Daegu Company was mixed with artificial clay and coated on the clay brick. This is a comparative example for comparing the photocatalyst performance under UV-A and visible light with the photocatalyst composition of the present invention and the photocatalyst which is commercialized.

[Comparative Example 2]

 Titanium dioxide (precursor titanium dioxide containing amorphous titanium dioxide and anatase rutile mixed phase) produced by Example 1 was heat-treated at 600 ° C to synthesize titanium dioxide mixed with anatase and rutile, and then mixed with artificial clay to obtain a clay brick To evaluate the photocatalytic performance.

[Comparative Example 3]

 The same procedure as in Example 1 was carried out except that artificial clay was changed to natural bentonite. 6 is a photograph of a binder liquid in which 2% of natural bentonite and synthetic artificial smacktite are dispersed.

[Table 1]

Table 1 summarizes the photocatalytic performance test results of the clay bricks produced in Examples 1 to 6 and Comparative Examples 1 to 3 under UV-A (ultraviolet irradiation).

2 and 3 show comparative examples 1 to 3 in which the photocatalyst-coated clay brick prepared in Examples 1 to 6 and the commercially available photocatalyst were dispersed in artificial clay and coated on the surface of the clay brick, 4 is a graph showing the decomposition ability measured for 15, 30, 60, 90 and 120 minutes under UV-A (FIG. 2) and fluorescent lamps under visible light irradiation (FIG. 3) Fig. 2 is an electron micrograph of the photocatalyst produced. As can be seen from FIG. 4, it can be seen that the particle size and shape of copper oxide-supported tungsten oxide and titanium peroxide photocatalyst are about 50 nm in size by high-energy speed ball milling and are generally spherical in shape.

From the results shown in the above Table 1, the photocatalytic performance (methylene blue) of the clay bricks having the photocatalytic function of the visible light responsive photocatalytic function produced in Examples 1 to 6 and the clay bricks prepared in Comparative Examples 1 to 3 was comparable to that of Comparative Example 1 , And Comparative Example 2 also exhibits excellent photocatalytic performance. On the other hand, the photocatalytic properties of the photocatalyst prepared according to the present invention are similar to those of the synthetic photocatalyst.

[Table 2]

Table 2 shows the results of evaluating the decomposition performance of methylene blue under a fluorescent lamp (visible light) of the clay bricks produced in Examples 1 to 6 and Comparative Examples 1 to 3. The clay bricks having the photocatalytic function of the visible light-responsive photocatalyst produced according to Examples 1 to 6 were superior to the clay bricks produced by the modification of the commercial photocatalyst, the synthetic photocatalyst and the artificial clay substitute binder manufactured by Comparative Examples 1 to 3, It can be confirmed that the photocatalytic property is remarkably excellent.

[Table 3]

Table 3 shows the acetaldehyde removal rates under the fluorescent lamps of clay bricks produced by Example 1 (synthetic photocatalyst) and Example 6 (photocatalyst manufactured by commercial raw material).

Fig. 5 is a graph showing measured values of acetaldehyde removal rate shown in Table 3. Fig.

 Since the clay brick produced according to the present invention exhibits a photocatalytic function in the region of ultraviolet light and visible light, it is possible not only to purify harmful volatile organic compounds in the room, but also to remove harmful gases such as NOx and SOx, Self-crying action is obtained by decomposing and removing, thereby providing a clean product at all times.

Although the present invention having been described above has been described with reference to a limited number of embodiments, it is to be understood that the present invention is not limited thereto and that various changes and modifications may be made without departing from the spirit and scope of the present invention by those skilled in the art. Various modifications and variations are possible within the scope of the appended claims.

Claims (8)

(1) preparing a photocatalyst mixed with tungsten oxide and titanium peroxide on which a transition metal oxide is supported;
(2) mixing 20 to 40% by weight of clay, 10 to 20% by weight of kaolin, 1 to 10% by weight of feldspar, and 40 to 50% by weight of fly ash;
(3) adding water to the mixture to knead the mixture so as to have a water content of 17 to 22%;
(4) extruding the kneaded material from a brick mold;
(5) drying the molded product at a temperature of 80 to 200 ° C for 36 to 48 hours;
(6) firing the dried shaped material at a temperature of 1,100 to 1,200 ° C for 24 to 36 hours and then cooling;
(7) 90 to 99% by weight of artificial clay binder prepared by dispersing 1 to 5% by weight of Smackite in 95 to 99% by weight of water is mixed with 1-10% by weight of the photocatalyst in a homogenizer at 11,000 rpm for 10 minutes Preparing a coating agent;
(8) applying the coating agent to the surface of the cooled mold with a low-pressure spray;
(9) A method for producing a clay brick having a photocatalytic function in response to a visible light, which comprises drying a molded article coated with the coating agent at a temperature ranging from room temperature to 250 ° C. The method according to claim 1,
The above step (1) was carried out by weighing 1.0 M (mol) of titanium oxysulfate, 1.0 M (mol) of the tungsten chloride, 0.05 M (mol) of the transition metal salt and 2.5 M (mol) of the ammonium carbamate, (S10)
The titanium oxyhydroxide aqueous solution and the tungsten chloride aqueous solution are stirred at 250 rpm in a stirrer and heated to maintain the reaction temperature at 80 ° C.
Injecting ammonium carbamate into the heated titanium oxysulfate aqueous solution to produce a titanium precursor (S30)
Injecting ammonium carbamate into the heated tungsten chloride aqueous solution to form a tungsten precursor; injecting the transition metal salt solution continuously at the time of completion of the injection to form a transition metal precursor on and around the tungsten precursor particle; (S40)
(S50) a step of obtaining a transition metal-supported tungsten precursor and a titanium dioxide precursor on the cake by filtering the titanium precursor and the tungsten precursor where the transition metal precursor is formed on and around the particle and then washing with ammonia water and distilled water;
Heating the tungsten precursor carrying the transition metal precursor on the cake to 500 ° C for 1 hour to crystallize it as an oxide and drying the resulting powder of titanium dioxide precursor on the cake under reduced pressure at 70 ° C to obtain a powder;
The transition metal oxide-supported tungsten oxide is mixed with 5 to 95% by weight of tungsten oxide and 5 to 95% by weight of titanium dioxide powder with 80 to 90% by weight of hydrogen peroxide to 10 to 20% A photocatalyst comprising tungsten and titanium peroxide; and (S70) a step of preparing a photocatalyst comprising tungsten and titanium peroxide. The method of claim 2,
In the step (S30), ammonium carbamate is injected into the heated aqueous titanium oxysulfate solution at a fixed rate of 50 ml / min, and the injection is stopped when the pH value of the aqueous solution of titanium oxysulfate is 7.0. And a photocatalytic function as a visible light responsive photocatalyst. The method of claim 2,
In step (S40), ammonium carbamate is injected into the heated aqueous tungstic chloride solution at a fixed rate of 50 ml / min to stop the injection at a time when the pH value of the tungstic chloride aqueous solution becomes 7.0 to generate a tungsten precursor And injecting the transition metal salt aqueous solution continuously at an injection rate of 50 ml / min at the time of completion of the injection, wherein the photocatalytic function is performed. The method of claim 2,
Wherein the step (S70) comprises pulverizing, mixing, and crystallizing the mixture in a zirconia ball mill container at a rotation speed of 1,100 rpm for 3 hours for 5 minutes, and for 1 minute at a rotation speed of a high energy speed ball mill. A method for producing a clay brick having a function. The method of claim 2,
Wherein the titanium dioxide precursor is composed of an amorphous titanium dioxide, an anatase, and a rutile mixed phase. The method of claim 2,
Wherein the transition metal salt is at least one selected from the group consisting of Pt salt, Au salt, Ag salt, Pd salt, Fe salt, Nb salt, Ru salt, Ir salt, Rh salt, Co salt, Bi salt and Cu salt. Type photocatalyst. A clay brick having a photocatalytic function in response to visible light, which is produced by the method of any one of claims 1 to 7.

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