KR101474242B1 - Method for producing titanium dioxide photocatalyst and method for procuding photocatalyst apparatus - Google Patents

Abstract

Disclosed is a method for producing a titanium dioxide powder and a method for manufacturing a photocatalyst device using the same.
A method of manufacturing a photocatalytic device, comprising: hydrolyzing a titanium dioxide precursor solution and a solvent to obtain a precipitate;
Adding an acid component to a solution containing the precipitate and aging the solution;
Centrifuging the aging solution to obtain wet titanium dioxide powder;
Drying and pulverizing the wet titanium dioxide powder to obtain a dried titanium dioxide powder having an average particle size of 15 to 25 nm and heating the mixture at a constant rate to perform a primary heat treatment;
Annealing the dried titanium dioxide powder at a temperature of 400 to 1100 DEG C for 30 minutes to 4 hours;
Forming a titanium dioxide photocatalyst layer by applying a dispersion solution in which a titanium dioxide powder annealed on the surface of the quartz glass substrate is dispersed in Na2SiO3; And
Forming a multi-layered structure of a quartz glass substrate on which a titanium dioxide photocatalyst layer is formed to form a multi-layer structure, and then connecting the quartz glass substrate to an ultraviolet lamp to manufacture the photocatalyst device;
.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for producing titanium dioxide powder and a method for manufacturing the same,

The present invention relates to a method for producing titanium dioxide powder and a method for manufacturing the same, and more particularly, to a method for producing a titanium dioxide powder capable of exhibiting excellent photocatalytic efficiency using a sol-gel method and a titanium dioxide photocatalyst layer The present invention relates to a method for producing a photocatalytic device.

The development of effective techniques for purifying air and water has become an important social goal. Photocatalysts are typically semiconductors with broad bandgaps that are activated by exposure to UV light in excess of the bandgap. When this photocatalyst is activated, pairs of electrons and holes are generated, and the lifetimes of these carriers are different. These two types of carriers participate in oxidation and reduction reactions.

Photocatalysts have been studied for a considerable period of time for a variety of applications, such as photochemical solar energy conversion, the production of synthetic fuels, and the decomposition of harmful and harmful contaminants in water and air.

TiO ₂ has considerable photoreactivity, high stability, and particularly low cost, which are very attractive as photocatalysts. The quest for new efficacy and low cost materials to improve the contaminated environment has become a major concern for researchers. In this regard, TiO ₂ -based photocatalysts have shown promising potential for decomposition of organic compounds in contaminated environments.

TiO ₂ has three main phases: anatase phase, rutile phase and brookite phase, the anatase phase is relatively unstable and the band gap is 3.2 eV, while the rutile phase has a stable phase at high temperature and the optical band gap Is 3.0 eV. Therefore, TiO ₂ can be used as a UV photocatalyst larger than the band gap of ~ 3.2 eV.

TiO ₂ -based photocatalysts are known to have far more effective photocatalytic properties than an anatase phase rather than a rutile phase. The crystal structure, density and adhesion of the membrane prepared by the sol - gel dip coating method are greatly affected by the molar ratio of the chemical precursor in the sol, the sol - gel preparation process and the subsequent heat treatment process.

Currently, ultraviolet lamps sold under the trade name of "Bionzone" are evaluated to have the best performance. This is because TiO ₂ Powder is mixed directly. By doing so, no separate photocatalytic device is installed outside. However, since the manufacturing cost of the glass tube is high, it is expensive to use the ultraviolet lamp in a general consumer (such as an air purifier manufacturer or a manufacturer of an apparatus for removing environmental pollution), and the ultraviolet lamp is not sold at will There is a problem that it can not be easily purchased because it is sold only by applying to its own product.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a method for producing titanium dioxide powder capable of exhibiting excellent photocatalytic efficiency using a sol-gel method.

Another object of the present invention is to provide a method for manufacturing a photocatalyst apparatus using the above-mentioned titanium dioxide powder.

In order to accomplish the above object, the present invention provides a method for producing titanium dioxide powder,

Hydrolyzing the titanium dioxide precursor solution and the solvent to obtain a precipitate;

Adding an acid component to a solution containing the precipitate and aging the solution;

Centrifuging the aging solution to obtain wet titanium dioxide powder;

Drying and pulverizing the wet titanium dioxide powder to obtain a dried titanium dioxide powder having an average particle size of 15 to 25 nm and heating the mixture at a constant rate to perform a primary heat treatment; And

Annealing the dried titanium dioxide powder at a temperature of 400 to 1100 DEG C for 30 minutes to 4 hours;

And a control unit.

Here, the titanium dioxide precursor

Is one selected from titanium isopropoxide (Ti (OCH (CH 3) 2) r, TTIP), tetraethoxytitanium (TEOT), tetraisopropoxytitanium (TIPT), and tetrabutoxytitanium (TBOT) .

The titanium dioxide precursor may be one selected from the group consisting of titanium tetrachloride (TiCl4), titanyl sulfate (Ti (SO4) 2), titanyl oxysulfate (TiO (SO4)

The hydrolysis may be performed by uniformly mixing the titanium dioxide precursor with a solvent, and then performing the reaction, wherein the solvent is at least one selected from the group consisting of water, alcohol, hexylene glycol, acetylacetone, and mixtures thereof .

The acid component may be at least one selected from the group consisting of acetic acid, hydrochloric acid, nitric acid, sulfuric acid, ascorbic acid (AA), and mixtures thereof.

According to another aspect of the present invention, there is provided a method of manufacturing a photocatalyst apparatus,

A method of manufacturing a photocatalytic device having a multilayer structure including a quartz glass substrate including a titanium dioxide photocatalyst layer and an ultraviolet lamp,

Hydrolyzing the titanium dioxide precursor solution and the solvent to obtain a precipitate;

Adding an acid component to a solution containing the precipitate and aging the solution;

Centrifuging the aging solution to obtain wet titanium dioxide powder;

Drying and pulverizing the wet titanium dioxide powder to obtain a dried titanium dioxide powder having an average particle size of 15 to 25 nm and heating the mixture at a constant rate to perform a primary heat treatment;

Annealing the dried titanium dioxide powder at a temperature of 400 to 1100 DEG C for 30 minutes to 4 hours;

Forming a titanium dioxide photocatalyst layer by applying a dispersion solution in which a titanium dioxide powder annealed on the surface of the quartz glass substrate is dispersed in Na2SiO3; And

A step of forming a multi-layered structure of a quartz glass substrate on which a titanium dioxide photocatalyst layer is formed to form a multi-layer structure, and then connecting the quartz glass substrate to an ultraviolet lamp to manufacture a photocatalyst device;

And a control unit.

Here, the titanium dioxide precursor

Is one selected from titanium isopropoxide (Ti (OCH (CH 3) 2) r, TTIP), tetraethoxytitanium (TEOT), tetraisopropoxytitanium (TIPT), and tetrabutoxytitanium (TBOT) .

The titanium dioxide precursor may be one selected from the group consisting of titanium tetrachloride (TiCl4), titanyl sulfate (Ti (SO4) 2), titanyl oxysulfate (TiO (SO4)

The hydrolysis may be performed by uniformly mixing the titanium dioxide precursor with a solvent, and then performing the reaction, wherein the solvent is at least one selected from the group consisting of water, alcohol, hexylene glycol, acetylacetone, and mixtures thereof .

The acid component may be at least one selected from the group consisting of acetic acid, hydrochloric acid, nitric acid, sulfuric acid, ascorbic acid (AA), and mixtures thereof.

According to the present invention, a titanium dioxide powder exhibiting effective catalytic activity for use in a photocatalytic device is prepared, a photocatalyst layer formed by coating the titanium dioxide powder on the surface of quartz glass in the form of a disc is formed, The photocatalytic device can be manufactured in a relatively simple manner. In addition, the photocatalyst device thus manufactured exhibits a photocatalytic effect equal to or superior to that of products that have been commercially available.

1 shows a photocatalyst apparatus according to the present invention,
FIG. 2 shows the X-ray diffraction results of the crystal structures of the TiO ₂ thin films prepared according to Examples 1 to 4 and the control group 1,
FIG. 3 shows the X-ray diffraction results of the crystal structures of the TiO ₂ powders prepared according to Examples 5 to 8 and the control group 2,
4 is a SEM photograph of TiO ₂ powder prepared according to Examples 9 to 14 (a to f)
5 is a particle size distribution of TiO ₂ powder prepared according to Examples 9 to 14,
6 is an SEM photograph of a TiO ₂ thin film produced according to Example 5,
FIG. 7 shows the results of measurement of reflection characteristics according to annealing temperatures of TiO ₂ powder prepared according to Examples 5, 6, 8, and 2,
Fig. 8 is a photograph showing an ultraviolet lamp and a measuring instrument,
Fig. 9 shows the results of evaluating ammonia decomposition characteristics of the photocatalyst apparatus according to Example 15 and Comparative Example 1,
10 shows the results of evaluating ammonia decomposition characteristics of the photocatalyst apparatus according to Example 15, Comparative Example 2, and Comparative Example 3,
11 shows the results of evaluating ammonia decomposition characteristics of the photocatalyst apparatus according to Example 15, the control group 3 and the comparative example 3 according to the air flow.

Hereinafter, the present invention will be described in more detail.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a,""an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

The present invention relates to a method for producing titanium dioxide in the form of powder and thin film, and a photocatalyst device comprising the titanium dioxide as a photocatalyst.

First, the titanium dioxide according to the present invention will be described.

The present invention provides a method for producing titanium dioxide in the form of a powder and a thin film using a sol-gel method.

According to an embodiment of the present invention, there is provided a method of producing titanium dioxide, comprising: hydrolyzing a titanium dioxide precursor solution to obtain a precipitate; Adding an acid component to the solution in which the precipitate is formed and aging the solution; Obtaining a dried powder or thin film from the aging solution; And annealing the dried powder or thin film.

In the first step, when the titanium dioxide precursor and the solvent are uniformly mixed and reacted, the titanium dioxide precursor is hydrolyzed, resulting in a white precipitate.

The titanium dioxide precursor may include both an organic titanium compound and an inorganic titanium compound. The organic titanium compound includes titanium alkoxide. More specifically, titanium isopropoxide (Ti (OCH (CH ₃ ) ₂ ) ₄ , TTIP ), Tetraethoxy titanium (TEOT), tetraisopropoxy titanium (TIPT), tetrabutoxy titanium (TBOT), and the like.

Specific examples of the inorganic titanium compound include titanyl chloride, TiCl ₄ , titanium sulfate, Ti (SO ₄ ) ₂ , and titanyl oxysulfate (TiO (SO ₄ ) But is not limited thereto.

The solvent for dissolving the titanium dioxide precursor solution may be at least one selected from the group consisting of water, lower alcohols having 1 to 5 carbon atoms, higher alcohols, hexylene glycol, acetylacetone, and mixtures thereof. It is more preferable to use an alcoholic solvent which is relatively easy to remove in the heat treatment process. In addition, the water is used for hydrolysis.

Since an exothermic reaction occurs strongly when the titanium dioxide precursor is mixed with water, it is preferable to mix the titanium dioxide precursor with strong stirring at a low temperature.

In the second step, an acid component is added to the solution in which the precipitate is formed and aged. The aging process is for obtaining a transparent solution, and it is preferable to add an acid component to maintain a constant pH, for example, 3 to 7. At this time, at least one acid component selected from the group consisting of acetic acid, hydrochloric acid, nitric acid, sulfuric acid, ascorbic acid (AA) and mixtures thereof is preferably used.

The aging process may be the same as the ultrasonic vibration process, and it is preferable to aged at room temperature for 4 to 6 hours. After the aging process, the solution becomes transparent.

In the third step, titanium dioxide powders and thin films are prepared from the transparent solution, respectively.

In the case of producing a titanium dioxide thin film from the transparent solution, the immersion and drying may be repeated or spin-coated using a predetermined substrate so as to have a desired thickness, and the thin film forming method is not particularly limited. The substrate may be a glass substrate, a ceramic substrate, a polymer substrate, or the like, and the kind thereof is not particularly limited.

When the titanium dioxide powder is prepared from the transparent solution, the transparent solution is centrifuged, and then the water and the supernatant of the solvent are separated and removed to obtain a wet powder. Then, the wet powder is dried and pulverized, and heated at a constant rate to perform a primary heat treatment. The primary heat treatment is to improve the properties of the titanium dioxide powder, which is an operation to improve the crystal growth of the finally obtained titanium dioxide powder.

The final step enhances the crystallinity by annealing the titanium dioxide thin film and the powder. The annealing can be performed at a temperature of 400 to 1100 ° C for 30 minutes to 4 hours, and is preferable in that it has an anatase phase which is a crystal capable of exhibiting a photocatalytic effect in the temperature range.

The titanium dioxide powder according to the present invention produced by the above process has an average particle size of 15 to 25 nm and has an anatase crystal structure predominantly, thereby effectively exhibiting photocatalytic activity.

The present invention also provides a photocatalytic device comprising the titanium dioxide powder and the thin film as a photocatalyst.

That is, as shown in FIG. 1, the photocatalyst apparatus according to the present invention includes a quartz glass substrate and an ultraviolet lamp, wherein the quartz glass substrate has a titanium dioxide photocatalyst layer on its surface, and the titanium dioxide photocatalyst layer The quartz glass substrate preferably has a multilayer structure.

In the present invention, a silica glass made of pure SiO ₂ is processed into a disc shape as shown in FIG. 1, a photocatalyst layer is formed on the surface of the silica glass using the titanium dioxide powder and the thin film produced in the present invention, A quartz glass substrate including a titanium dioxide photocatalyst layer is bundled into a multi-layered structure, and then has a structure connected to an ultraviolet lamp.

Conventional products are manufactured using aluminum or stainless steel. However, since the side coated with TiO ₂ is irradiated with the direction of irradiation due to the emission of ultraviolet rays, the reaction rate of the photocatalyst is low and the substrate material coated with TiO ₂ itself is opaque, There was a problem that the reaction was difficult to occur.

However, in the present invention, since quartz glass which transmits ultraviolet rays well is used as a substrate, the ultraviolet rays are easily permeated and an effective photocatalytic reaction can take place. In addition, when a raw quartz glass plate is processed into a funnel shape, It is possible to further increase the photocatalytic reaction by irradiating more ultraviolet rays to the photocatalyst.

The titanium dioxide photocatalyst layer according to the present invention may be formed by coating a titanium dioxide powder or a thin film. When the titanium dioxide powder is used, the photocatalyst layer is formed by dispersing the powder in Na2SiO3 or a suitable polymer resin, etc. However, the method is not particularly limited.

In addition, when the titanium dioxide thin film is used, the photocatalyst layer can be formed by laminating the thin film or by using an appropriate adhesive, but the method is not particularly limited.

The titanium dioxide-based photocatalyst layer according to the present invention has a characteristic of exhibiting activity in the UV-C section of 184 to 254 nm.

Hereinafter, preferred embodiments of the present invention will be described in detail. The following examples are intended to illustrate the present invention, but the scope of the present invention should not be construed as being limited by these examples. In the following examples, specific compounds are exemplified. However, it is apparent to those skilled in the art that equivalents of these compounds can be used in similar amounts.

Example  1 to 4: TiO ₂  Fabrication of thin films

To 10 ml of pure ethanol was added 1.1 g of titanium isopropoxide (TTIP) as a precursor of TiO ₂ and hydrolyzed under constant stirring to produce a white precipitate. To this solution was added 3M CH ₃ COOH to maintain the acidic condition (pH 3-7). This solution was ultrasonically vibrated for 12 minutes and aged at room temperature for 12 hours. The finally obtained solution was in a transparent state.

For the preparation of the TiO ₂ thin film, the surface of 100 mm ₂ was ultrasonicated for 5 minutes, the organic material was completely removed with acetone, and then borosilicate glass rinsed with pure water was used as the substrate.

The borosilicate glass substrate was immersed in the transparent solution for 60 minutes (immersion) and then lifted at a rate of 1 cm / min. Then, the substrate coated with the solution was dried at 100 DEG C for 15 minutes. The immersion and drying process was repeated four times to obtain a TiO2 thin film (d? 8 占 퐉) having a desired thickness.

Subsequently, annealing was continuously performed at different temperatures of 500 ° C (Example 1), 700 ° C (Example 2), 900 ° C (Example 3), and 1100 ° C (Example 4). Each annealing temperature was raised at a rate of 5 DEG C / min.

Control group 1: TiO ₂  Fabrication of thin films

A TiO ₂ thin film was prepared in the same manner as in Examples 1 to 4 except that annealing was performed at 300 캜.

Example  5 to 8: TiO ₂  Production of powder

For the preparation of the TiO ₂ thin films of Examples 1 to 4, the transparent solution prepared by the sol-gel method was centrifuged at 8000 rpm for 20 minutes, and the supernatant such as water and ethanol was separated and removed to obtain a wet powder .

The wet powder was dried in an oven at 60 < 0 > C for 48 hours. The dried powder was finely pulverized using a firefly. The powder was heated at a rate of 1.5 캜 / min and heat-treated at 300 캜 for 2 hours.

The powder was then annealed for 3 hours at 500 ° C (Example 5), 700 ° C (Example 6), 900 ° C (Example 7), and 1100 ° C (Example 8), respectively. At this time, the heating rate was 20 ° C / min, and the annealed powder was slowly cooled to room temperature.

Control 2: TiO ₂  Production of powder

TiO ₂ powders were prepared in the same manner as in Examples 5 to 8 except that the annealing treatment was conducted at 300 ° C.

Experimental Example  One : TiO ₂  Determination of crystalline structure of thin film and powder

The crystal structures of the TiO ₂ thin films and powders prepared according to Examples 1 to 4, Examples 5 to 8, and Controls 1 and 2 were measured by X-ray diffraction (XRD, Phillips model PW1830 diffractometer) 2 and 3, respectively.

_{2, which} is an XRD result of a TiO ₂ thin film, the relative peak peaks of the thin TiO ₂ are weaker than those of the TiO ₂ powder. The results showed that the crystal growth of the TiO ₂ thin film was not better than that of the TiO ₂ powder. Moreover, diffraction peaks on rutile appeared at lower annealing temperatures than TiO ₂ powder.

Further, according to the following Figure 3 XRD results of the TiO ₂ powder, it is annealed at a low temperature in the XRD pattern of the TiO ₂ powder diffraction peaks having an anatase crystal structure, TiO ₂ (101) was more strongly observed raising the annealing temperature . This clearly showed that the crystallinity of the TiO ₂ powder was increased with the increase of the annealing temperature. A new diffraction peak appeared at 700 ° C. This peak shows that the TiO ₂ powder begins phase transformation from anatase to rutile.

Example  9-14: TiO ₂  Production of powder

The water content in the ethanol was measured by the same procedure as in Example 1, except that the water content in ethanol was changed from 0% (Example 9), 1% (Example 10), 2% (Example 11), 3% Example 14), TiO ₂ powder was prepared in the same manner as in Examples 5 to 8 above.

Experimental Example  2 : TiO ₂  Check the surface structure of thin film and powder

The crystal structures of the TiO ₂ powders and thin films prepared according to Examples 9 to 14 and Example 5 were observed using SEM (JOEL JSM-6330F), and the results are shown in FIGS. 4 and 6, respectively . The particle size distribution of TiO ₂ powder prepared according to Examples 9 to 14 is shown in FIG. 5.

SEM photographs of the TiO ₂ powders prepared according to Examples 9 to 14 of FIGS. 4 (a) to 4 (f) and the particle size distributions of the TiO ₂ particles formed in ethanol even with moisture content of 5% It can be confirmed that there is no particular effect on size, which is in good agreement with the results reported in previous studies. The average particle sizes of the TiO ₂ powders prepared according to Examples 9 to 14 were found to be 15 to 23, 16 to 21, 15 to 24, 16 to 20, 15 to 22 and 14 to 23 nm, respectively.

Also, referring to FIG. 6, which is an SEM image of the TiO ₂ thin film prepared according to Example 5, it can be confirmed that small-sized TiO 2 crystals grow well and uniformly on the substrate.

Experimental Example  3: Annealing  Temperature dependent TiO ₂  Measure the reflection properties of particles

The reflection characteristics of the TiO ₂ powders prepared according to Examples 5 to 6, 8 and Comparative Example 2 according to various annealing temperatures were measured by UV-visible spectroscopy. The results are shown in FIG.

As shown in FIG. 7, as the annealing temperature increases, the reflection characteristic shows a red-shift toward red. Also, the bandgap for TiO ₂ powder was calculated. The band gap of TiO ₂ powder decreased with increasing annealing temperature. In the case of TiO ₂ particles, the anatase phase with a band gap of 3.2 eV at the lower annealing temperature proved to be more dominant. However, with increasing annealing temperature TiO ₂ was converted to a rutile phase with a bandgap of 3.0 eV.

Example  15: Photocatalyst  Manufacturing of devices

Silica glass made of pure SiO ₂ was processed into a disc shape as shown in FIG. 1. The titanium dioxide powder prepared in Example 5 was dispersed in Na2SiO3 to prepare a dispersion solution. The dispersion solution was coated on the surface of the quartz glass disk to form a photocatalyst layer having a thickness of 10 mu m.

Then, the quartz glass substrate including the titanium dioxide photocatalyst layer was bundled into a multi-layer structure to form a multilayer structure, and then connected to an ultraviolet lamp (a 10 W-class harsh product emitting ultraviolet rays of 184 nm) to produce a photocatalyst device.

Comparative Example  One

A photocatalytic device according to Example 15 of the present invention was compared with a commercially available ultraviolet lamp (a 10 W type harsh product emitting ultraviolet rays of 184 nm).

Experimental Example  4 : Photocatalyst  Characterization of the device

Next, as shown in FIG. 8, ammonia (25%) by a photocatalyst apparatus (Example 15) including a photocatalyst layer coated with TiO ₂ and an ultraviolet lamp (Comparative Example 1) Concentration) gas was investigated by time.

After dropping a drop of ammonia (25% concentration) into a closed space, the ammonia gas is spread in the closed space by diffusion and reaches a constant saturation concentration. The ammonia concentration is measured by an ammonia gas concentration meter and the ultraviolet lamp is turned on . The ultraviolet lamp used was a UV-C lamp which emits mainly 184 nm and 254 nm. Particularly, UV lamps with a large amount of ultraviolet radiation of 184 nm were applied in a half-shielded manner, and decomposition characteristics of ammonia gas were measured for 60 minutes at intervals of 3 minutes after the ultraviolet lamp was turned on. Ammonia concentration was measured with a ToxiRAE portable meter.

Next, FIG. 9 shows ammonia gas decomposition characteristics of a UV-C lamp (10W class, Hansung product) emitting 184 nm ultraviolet rays. An ultraviolet lamp emitting 184 nm ultraviolet rays generates ozone due to ultraviolet rays of this wavelength . In the case of the photocatalyst apparatus including the photocatalyst layer coated with TiO ₂ (Example 15), the initial value was maintained for 6 minutes and then decreased by about 1 ppm every 3 minutes thereafter.

As a result of measurement of ammonia gas decomposition characteristics by an ultraviolet lamp not containing a photocatalyst layer (Comparative Example 1), the concentration value similar to the initial value was maintained for a predetermined period regardless of the passage of time, It was confirmed that the concentration of ammonia gas was lowered due to the result of gas decomposition by the ozone. Unlike UV-B lamps, UV-C lamps emit very strong UV radiation at 184 nm, which is a result of the relatively high amount of ozone generated by UV-B lamps.

Comparative Example  2

A photocatalyst device (manufactured by Oasis Inc.) in which an aluminum original plate was coated with TiO ₂ coated thereon was installed on the outer surface of an ultraviolet lamp.

Comparative Example  3

A glass tube for use in the manufacture of the ultraviolet lamp as a product commercially available TiO ₂ And a photocatalyst device (Biozon) manufactured by directly mixing powders was used.

Experimental Example  5: Photocatalyst  Evaluation of decomposition characteristics of devices

The decomposition performance of the three products prepared in Example 15, Comparative Example 2, and Comparative Example 3 was measured using ammonia gas. The results are shown in FIG. 10.

Referring to FIG. 10, in Comparative Example 2, ammonia gas was rapidly decomposed in the early stage, and after 6 minutes, it was saturated and no further decomposition was observed. This means that the decomposition of ammonia by the photocatalyst It can not be done.

Further, it can be seen that the decomposition is continuously performed comparatively well in Comparative Example 3 as compared with Comparative Example 2, and it can be judged that the photocatalytic device operates effectively.

Further, it can be confirmed that the photocatalytic device according to Example 15 of the present invention decomposes ammonia more favorably than that of Comparative Example 3 and continuously decomposes. That is, it can be seen that the photocatalyst device comprising the titanium dioxide produced according to the present invention as a photocatalyst layer and introducing it into a laminate structure exhibits a photocatalytic effect equal to or better than that of a conventional photocatalyst.

Experimental Example  6: Photocatalyst  Characterization of the device

The characteristics of the photocatalytic device in the case of causing the air flow in the experimental apparatus for ammonia gas decomposition and in the case of stopping the air flow were evaluated, and the results are shown in Fig.

The photocatalyst of Example 15 and the photocatalyst of Example 15 of the present invention were used in the case of causing air flow, but the condition of stopping the air flow was used as the control group 3, and the biodevice product of Comparative Example 3 and its characteristics Respectively.

As shown in FIG. 11, when the air-generating fan was not operated (control group 3), the ammonia located in the sensor portion of the ammonia concentration measuring device was decomposed well by the action of the photocatalytic device and ultraviolet rays.

It is observed that when the fan is turned and air flow is caused, the remaining ammonia gas does not decompose and moves again to the vicinity of the sensor, resulting in a slow decrease in ammonia gas concentration. (Example 15)

In this case as well, it can be seen that the ammonia gas is decomposed earlier than the biozon product of Comparative Example 3. [

From these results, it can be seen that the photocatalytic device manufactured according to the present invention exhibits a photocatalytic effect similar or superior to that of the conventional photocatalytic device, both in the case of air flow and in the case of stop of air flow.

102 ... ultraviolet lamp 104 ... quartz glass substrate

Claims (10)

Hydrolyzing the titanium dioxide precursor solution and the solvent to obtain a precipitate;
Adding an acid component to a solution containing the precipitate and aging the solution;
Centrifuging the aging solution to obtain wet titanium dioxide powder;
Drying and pulverizing the wet titanium dioxide powder to obtain a dried titanium dioxide powder having an average particle size of 15 to 25 nm and heating the mixture at a constant rate to perform a primary heat treatment; And
Annealing the heat-treated titanium dioxide powder at a temperature of 400 to 1100 占 폚 for 30 minutes to 4 hours through the first heat treatment;
≪ / RTI >
The method according to claim 1,
The titanium dioxide precursor is selected from titanium isopropoxide (Ti (OCH (CH 3) 2) r, TTIP), tetraethoxy titanium (TEOT), tetraisopropoxy titanium (TIPT), tetrabutoxy titanium Wherein the titanium dioxide powder is one selected from the group consisting of titanium dioxide and titanium dioxide.
The titanium dioxide precursor according to claim 1, wherein the titanium dioxide precursor is one selected from the group consisting of titanyl chloride (TiCl4), titanium sulfate (Ti (SO4) 2), titanyl oxysulfate (TiO By weight based on the weight of the titanium dioxide powder.
The method of claim 1, wherein
The hydrolysis is carried out by uniformly mixing the titanium dioxide precursor and the solvent,
Wherein the solvent is at least one selected from the group consisting of water, alcohol, hexylene glycol, acetylacetone, and mixtures thereof.
The method according to claim 1, wherein the acid component is at least one selected from the group consisting of acetic acid, hydrochloric acid, nitric acid, sulfuric acid, ascorbic acid (AA), and mixtures thereof.
A method of manufacturing a photocatalytic device having a multilayer structure including a quartz glass substrate including a titanium dioxide photocatalyst layer and an ultraviolet lamp,
Hydrolyzing the titanium dioxide precursor solution and the solvent to obtain a precipitate;
Adding an acid component to a solution containing the precipitate and aging the solution;
Centrifuging the aging solution to obtain wet titanium dioxide powder;
Drying and pulverizing the wet titanium dioxide powder to obtain a dried titanium dioxide powder having an average particle size of 15 to 25 nm and heating the mixture at a constant rate to perform a primary heat treatment;
Annealing the heat-treated titanium dioxide powder at a temperature of 400 to 1100 占 폚 for 30 minutes to 4 hours through the first heat treatment;
Forming a titanium dioxide photocatalyst layer by applying a dispersion solution in which a titanium dioxide powder annealed on the surface of the quartz glass substrate is dispersed in Na2SiO3; And
A step of forming a multi-layered structure of a quartz glass substrate on which a titanium dioxide photocatalyst layer is formed to form a multi-layer structure, and then connecting the quartz glass substrate to an ultraviolet lamp to manufacture a photocatalyst device;
Wherein the photocatalyst production method comprises the steps of:
The method according to claim 6,
The titanium dioxide precursor is selected from titanium isopropoxide (Ti (OCH (CH 3) 2) r, TTIP), tetraethoxy titanium (TEOT), tetraisopropoxy titanium (TIPT), tetrabutoxy titanium Wherein the photocatalyst material is one of the photocatalyst material and the photocatalyst material.
The method of claim 6, wherein the titanium dioxide precursor is one selected from the group consisting of titanyl chloride (TiCl4), titanium sulfate (Ti (SO4) 2), titanyl oxysulfate (TiO Gt;
The method of claim 6, wherein
The hydrolysis is carried out by uniformly mixing the titanium dioxide precursor and the solvent,
Wherein the solvent is at least one selected from the group consisting of water, alcohol, hexylene glycol, acetylacetone, and mixtures thereof.
7. The method of claim 6, wherein the acid component is at least one selected from the group consisting of acetic acid, hydrochloric acid, nitric acid, sulfuric acid, ascorbic acid (AA), and mixtures thereof.

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