CN103079703B - The manufacture method of photochemical catalyst tunicle and photochemical catalyst tunicle - Google Patents

Abstract

The object of the invention is to the high fabrication yield of the titanium dioxide tunicle realizing having supported iron.In order to reach such object, generating the water slurry being mixed with titania powder and ferric chloride in aqueous solution, the water slurry generated is carried out spraying plating by spray technique.FeO (OH) can be made when spraying plating to support in titania powder while by photochemical catalyst tunicle film forming, therefore realize the significantly raising of fabrication yield.

Description

Method for producing photocatalyst coating and photocatalyst coating

technical field

The present invention relates to a method for producing a photocatalyst coating and a photocatalyst coating. Specifically, it relates to a method for producing a photocatalyst film and a photocatalyst film having a photocatalyst function capable of detoxifying, antibacterial, and sterilizing pollutants, for example.

Background technique

With the progress of an aging society, the proportion of elderly people with weakened immunity in the total population tends to increase. Along with this, from the viewpoint of prevention of nosocomial infection, food poisoning, etc., medical sites, food production and Strengthening of sanitation management at processing sites has become an urgent issue. In view of such a social background, various antimicrobial processed products have been developed, and in recent years, the utilization of the photocatalyst function for antimicrobial processing has attracted attention in particular.

Here, the so-called "photocatalytic function" refers to a catalyst substance that becomes excited when irradiated with light energy greater than the band gap energy of its conduction band and valence band, and generates electron-hole pairs to cause oxidation and reduction reactions ( Photo-semiconductor material) has the function.

Among photocatalysts, photocatalysts using titanium dioxide (TiO ₂ ), especially titanium dioxide particles having a rutile crystal structure, are inexpensive, have excellent chemical stability, and have high catalytic activity. Decomposition activity, can be combined with bacterial cells to decompose harmful substances such as endotoxin and toxins produced by bacteria (such as verotoxin produced by pathogenic Escherichia coli), which are components of the outer wall of Gram-negative bacteria It has the advantage of being harmless to the human body.

Therefore, studies and applications of photocatalysts using titanium dioxide have been conducted, and titanium dioxide photocatalysts have been widely used for antibacterial processing of food containers and building materials (for example, refer to Patent Document 1 and Patent Document 2).

It should be noted that, since titanium dioxide exhibits photocatalytic activity only under ultraviolet irradiation, sufficient catalytic activity cannot be exhibited under indoor light that hardly contains ultraviolet components. Therefore, there is known a technique in which a metal such as iron or a metal complex such as FeCl ₃ or a metal complex such as FeCl 3 , that is, an iron compound, is supported on titanium dioxide to exhibit photocatalytic activity under irradiation with visible light.

However, conventionally, in the case of producing a photocatalyst film exhibiting photocatalytic activity under irradiation with visible light, a photocatalyst composition containing a titanium dioxide powder carrying a sensitizer is dispersed in, for example, a paint or the like, or in a target building material or the like. The surface is coated to produce a photocatalyst film.

Specifically, for example, first, titanium dioxide (TiO ₂ ) is immersed in an aqueous solution of ferric chloride (FeCl ₃ ) as a sensitizer, and stirred to prepare iron or iron compounds supported on titanium dioxide, and iron or iron compounds to be supported. Then, the photocatalyst composition is dispersed in a paint, and the photocatalyst composition is coated on the surface of a building material or the like (for example, refer to Patent Document 3).

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2007-51263

Patent Document 2: Japanese Patent Laid-Open No. 2006-346651

Patent Document 3: Japanese Patent Laid-Open No. 2007-090336

Contents of the invention

The problem to be solved by the invention

However, a photocatalyst composition in which an iron compound is supported on titanium dioxide requires an extremely long time in its processing and production steps, and improvement in quality, reduction in cost, or stabilization of these by shortening the production process is required.

The present invention was made in view of the above points, and an object of the present invention is to provide a method for producing a photocatalyst coating and a photocatalyst coating capable of shortening the production process, stabilizing the quality, and reducing the cost.

means to solve the problem

In order to achieve the above objects, the method for producing a photocatalyst film according to the present invention includes: forming at least one compound containing photocatalyst particles, water-soluble metal complexes or water-soluble metal salts selected from Fe, Cu, Cr, and Ni, and water. The process of the slurry; the slurry is sprayed and at least one metal ion of the above-mentioned compound is reacted with water to form at least the hydroxide, oxyhydroxide or oxide of Fe, Cu, Cr, Ni One form is a step of loading the photocatalyst particles in the above-mentioned slurry and laminating the photocatalyst particles on the object at the same time.

Here, by forming a slurry containing photocatalyst particles, at least one compound selected from water-soluble metal complexes or water-soluble metal salts of Fe, Cu, Cr, and Ni, and water, the slurry is sprayed, and Fe , Cu, Cr, Ni water-soluble metal complexes or metal ions of water-soluble metal salts react with water to form very fine hydroxides, oxyhydroxides or oxides of Fe, Cu, Cr, Ni in nanometer size, These hydroxides, oxyhydroxides or oxides are uniformly distributed and supported on the surface of the photocatalyst particle.

In addition, at least one form of hydroxide, oxyhydroxide, or oxide of Fe, Cu, Cr, and Ni produced by spraying the slurry to react metal ions of at least one of the above compounds with water is supported. The photocatalyst particles in the slurry, and the photocatalyst particles are laminated on the object at the same time, that is, the hydroxide, oxyhydroxide or oxidation of Fe, Cu, Cr, and Ni At least one form of the substance is not carried on the photocatalyst particles, and the slurry is sprayed, and the nano-sized very fine hydroxides, oxyhydroxides, or oxides of Fe, Cu, Cr, and Ni are dispersed on the surface of the photocatalyst particles. By being supported, it is possible to greatly shorten the manufacturing process and stabilize the performance and quality of the photocatalyst functional film.

In addition, as a "water-soluble metal complex of Fe, Cu, Cr, Ni", for example, [Cu(NH ₃ ) ₄ ] ²⁺ , [Fe(CN) ₆ ] ^4- , [Fe(CN) ₆ ] ^3- , C ₁₀ H ₁₂ FeN ₂ O ₈ , etc. Examples of "water-soluble metal salts of Fe, Cu, Cr, and Ni" include FeCl ₃ , Fe ₂ (SO ₄ ) ₃ , Fe(NO ₃ ) _3. CuSO ₄ , Cu(NO ₃ ) ₂ , CuCl ₂ , Ni(NO ₃ ) ₂ , NiCl ₂ , NiSO ₄ , Cr(NO ₃ ) ₃ , etc.

In addition, examples of "hydroxides, oxyhydroxides, or oxides of Fe, Cu, Cr, and Ni formed by the reaction of water-soluble metal complexes of Fe, Cu, Cr, and Ni with water" include CuO, Cu( OH) ₂ , FeO(OH), Fe(OH) ₃ , etc., as "the oxides, oxyhydroxides or oxides of Fe, Cu, Cr, and Ni formed by the reaction of metal salts of Fe, Cu, Cr, and Ni with water substances", for example, FeO(OH), Fe(OH) ₃ , Cu(OH) ₂ , CuO, Ni(OH) ₂ , NiO(OH), Cr(OH) ₃ , Cr ₂ O(OH) ₄ , Cr ₂ O ₃ etc.

It should be noted that, in the spraying process, since the spraying flame is close to the vacuum state at a high speed, the metal ions and slurry of water-soluble metal complexes or water-soluble metal salts of Fe, Cu, Cr, Ni occur It is considered that negative ions such as chloride ions and nitrate ions are volatilized by the heat of spraying and diffused in the atmosphere.

Here, when hydroxides, oxyhydroxides, or oxides of Fe, Cu, Cr, or Ni exhibit a visible light response function, under visible light irradiation, the supported Fe, Cu, Cr, or Ni hydroxides Excited by substances, oxyhydroxides or oxides, the excited electrons move to the side of the photocatalyst particle, thereby oxidation reaction occurs on the surface of the hydroxide, oxyhydroxide or oxide of Fe, Cu, Cr, Ni, and the surface of the photocatalyst particle A reduction reaction occurs, and visible light responsiveness is exhibited (see FIG. 1A ).

It should be noted that FeO(OH), Fe(OH) ₃ , Cu(OH) ₂ , CuO , Ni(OH) ₂ , NiO(OH), Cr(OH) ₃ , Cr ₂ O(OH) ₄ , Cr ₂ O ₃ , etc.

In addition, in the case where the hydroxide, oxyhydroxide or oxide of Fe, Cu, Cr, or Ni exhibits a co-catalyst function, the photocatalyst particles are excited under ultraviolet irradiation, and the electrons are excited to the hydrogen of Fe, Cu, Cr, or Ni. Oxides, oxyhydroxides, or oxides move sideways, whereby oxidation reactions occur on the surface of photocatalyst particles, reduction reactions occur on the surfaces of hydroxides, oxyhydroxides, or oxides of Fe, Cu, Cr, and Ni, and electrochemical separation , the photocatalyst performance is improved (see Figure 1B).

In addition, _Fe2O3 , _CuO , NiO etc. are mentioned as the hydroxide, oxyhydroxide, or oxide of Fe, Cu, Cr, Ni which exhibits a cocatalyst function.

In addition, the method for producing a photocatalyst film according to the present invention includes: forming a slurry containing photocatalyst particles, at least one compound selected from the group consisting of Fe, Cu, Cr, and Ni water-soluble metal complexes or water-soluble metal salts, and water. The step of spraying the above-mentioned slurry and laminating the photocatalyst particles contained in the slurry on the object.

Here, a slurry containing photocatalyst particles, at least one compound selected from water-soluble metal complexes or water-soluble metal salts of Fe, Cu, Cr, and Ni, and water is formed, and the slurry is sprayed, thereby Metal ions of water-soluble metal complexes or water-soluble metal salts of Fe, Cu, Cr, and Ni react with water to form very fine hydroxides, oxyhydroxides, or oxides of Fe, Cu, Cr, and Ni in nanometer sizes , these hydroxides, oxyhydroxides or oxides are uniformly distributed and supported on the surface of the photocatalyst particles.

In addition, the photocatalyst particles contained in the slurry are laminated on the object by spraying the slurry, that is, by oxidizing the hydroxides and oxyhydroxides of Fe, Cu, Cr, and Ni in advance before laminating the photocatalyst particles on the object. At least one form of substance or oxide is not carried on the photocatalyst particles, and the slurry is sprayed, and the hydroxides, oxyhydroxides or oxides of Fe, Cu, Cr, and Ni with a nanometer size are very finely dispersed in the photocatalyst particles By being supported on the surface, the production process can be greatly shortened and the performance and quality of the photocatalyst functional film can be stabilized.

Moreover, the slurry containing photocatalyst particles such as titanium dioxide also contains antibacterial metals (for example, containing at least one of silver-based, copper-based, zinc-based, aluminum-based, nickel-based, cobalt-based or chromium-based metals), Antibacterial metal salts or antibacterial metal complexes, the slurry containing antibacterial metals, antibacterial metal salts or antibacterial metal complexes is sprayed, so that it can be selected from metals, metal salts, metal complexes, hydroxyl By stacking antibacterial metal or antibacterial metal complex in at least one form of oxide, hydroxide, or oxide, a photocatalyst functional film with strong antibacterial effect can be produced.

In addition, by adding a pigment to a slurry containing photocatalyst particles such as titanium dioxide, and spraying a slurry containing both photocatalyst particles and pigments, photocatalyst particles containing pigments can be laminated, and colorful designs can be produced. High photocatalyst coating.

In addition, by adding an adsorbent (for example, zeolite, etc.) to a slurry containing photocatalyst particles such as titanium dioxide, and spraying a slurry containing both photocatalyst particles and the adsorbent, the adsorbent can be laminated together with the photocatalyst particles, A photocatalyst film having a high gas adsorption capacity can be produced.

In addition, in order to achieve the above object, the photocatalyst film according to the present invention is produced by forming at least one compound containing photocatalyst particles, water-soluble metal complexes or water-soluble metal salts selected from Fe, Cu, Cr, and Ni. and water slurry, the slurry is sprayed, and at least one of the hydroxides, oxyhydroxides or oxides of Fe, Cu, Cr, and Ni formed by reacting metal ions of at least one of the above compounds with water In one form, the photocatalyst particles in the above-mentioned slurry are supported, and the photocatalyst particles are laminated on the object.

In addition, the photocatalyst film according to the present invention is produced by forming a slurry containing photocatalyst particles, at least one compound selected from the group consisting of Fe, Cu, Cr, and Ni water-soluble metal complexes or water-soluble metal salts, and water. , the above-mentioned slurry is thermally sprayed, and the photocatalyst particles contained in the slurry are laminated on the object.

It should be noted that, examples of objects to be laminated with photocatalyst particles include ceramic tiles, sanitary ware, glass, mirrors, concrete building materials, resin building materials, metal building materials, resin films, metal fibers, glass fibers, and carbon fibers. , filters using these fibers, and the like.

The effect of the invention

In the production method of the photocatalyst coating to which the present invention is applied, the photocatalyst coating can be produced in a greatly shortened production process, so the variation in the quality and performance of the coating is small, and high quality and production yield can be realized. In addition, high quality can be realized also in the photocatalyst film to which the present invention is applied.

Description of drawings

FIG. 1A is a schematic diagram for explaining the visible light response function.

Fig. 1B is a schematic diagram for explaining the function of the co-catalyst.

Fig. 2 is a schematic diagram for explaining a thermal spraying device.

FIG. 3 is an analysis result of a crystal structure using XRD of a photocatalyst film obtained by the method for producing a photocatalyst film to which the present invention is applied.

FIG. 4 is an analysis result of a crystal structure using XRD of a photocatalyst film obtained by a conventional method for producing a photocatalyst film.

FIG. 5 is an analysis result of XRD crystal structure using a photocatalyst coating obtained by supporting iron after formation of the titania coating.

6 is a conceptual diagram of a test evaluation method for a gas decomposition performance test of a photocatalyst film.

Fig. 7 is the result of acetaldehyde gas decomposition test (1).

Fig. 8 is the test result of acetaldehyde gas decomposition (2).

FIG. 9 is a conceptual diagram of a test method for evaluating the bactericidal effect of a photocatalyst coating.

Fig. 10 is a result of an evaluation test of the bactericidal effect of the photocatalyst coating.

Fig. 11 is a result of an acetaldehyde gas decomposition test to which the photocatalyst film of the present invention is applied.

Fig. 12 is the result of the Escherichia coli sterilization test to which the photocatalyst film of the present invention is applied.

FIG. 13 is an analysis result of XRD crystal structure of a photocatalyst film carrying a pigment.

FIG. 14 is an analysis result of the crystal structure by XRD using the photocatalyst film obtained by the pre-loading method.

FIG. 15 is an analysis result of crystal structure by XRD using the photocatalyst film obtained by the post-loading method.

Detailed ways

Hereinafter, modes for implementing the invention (hereinafter referred to as "embodiments") will be described with reference to the drawings.

＜1. Loading of iron＞

In an example of the manufacturing method of the photocatalyst film to which this invention was applied, it is established in two processes of (1) aqueous slurry production process and (2) thermal spray coating formation process. Hereinafter, each process will be described in detail.

[1. Water slurry generation process]

In an example of the method for producing a photocatalyst film to which the present invention is applied, the Ti component of titanium dioxide powder (TiO ₂ ) and the Fe component of ferric chloride aqueous solution (FeCl ₃ ) are Ti:Fe=99:1 by weight ratio. Method A water slurry (concentration: 30% by weight) was generated using titanium dioxide powder and an aqueous ferric chloride solution.

Specifically, an aqueous slurry was generated using rutile-type titanium dioxide powder having a particle diameter of about 30 nm and an aqueous ferric chloride solution. In addition, in the aqueous slurry, the rutile-type titanium dioxide powder is aggregated to form a particle diameter of about 1 μm to 5 μm.

Here, in this embodiment, the case where titanium dioxide particles are used as an example of photocatalyst particles will be described. However, the photocatalyst particles do not necessarily have to be titanium dioxide particles, and may be, for example, tungsten oxide or tin oxide. However, it is preferable to use titanium dioxide as a photocatalyst in consideration of its low-cost chemical stability and high catalytic activity.

In addition, in this embodiment, as an example of the sensitizer, the case of using ferric chloride (FeCl ₃ ), that is, a water-soluble metal salt of iron (Fe), is cited and described as an example, but the sensitizer does not necessarily have to be It is a water-soluble metal salt or a water-soluble metal complex of iron (Fe), and may be a water-soluble metal salt or a water-soluble metal complex of copper (Cu), chromium (Cr), or nickel (Ni). Among them, in consideration of the low cost, it is preferable to use a water-soluble metal salt or a water-soluble metal complex of iron (Fe) as a sensitizer.

Table 1 shows the titanium oxide crystal strength counts measured by XRD for the case where the water slurry concentration is 10% by weight and the case where it is 30% by weight. It should be noted that the "titanium oxide crystal strength count" means the adhesion rate (existence rate) of the material.

[Table 1]

It is known from Table 1 that when the water slurry concentration is 10% by weight and the situation of 30% by weight is compared, the higher the water slurry concentration is, the more the material input increases, which can increase the adhesion. On the other hand, when the concentration of the water slurry exceeds 30% by weight, the viscosity of the water slurry increases too much, making it difficult to feed the slurry during thermal spraying. Therefore, in this embodiment, the water slurry concentration is set to 30% by weight.

[2. Spray coating film formation process]

In one example of the manufacturing method of the photocatalyst coating to which this invention was applied, thermal spraying is performed continuously using the produced|generated water slurry, and a photocatalyst coating is formed into a film.

Here, in the thermal spray coating forming process, for example, a high-speed thermal spray device with a variable thermal spray temperature described in JP-A-2005-68457 can be used. Specifically, as shown in FIG. The combustion of oxygen and kerosene pumps the resulting water slurry onto the high-speed flame sprayed from the spraying gun, and collides with the target substrate at high speed to form a photocatalyst film. It should be noted that by mixing high-pressure air with a booster compressor in high-pressure oxygen, a reduction in the amount of oxygen used and a further increase in speed of the flame (flame) can be achieved.

Regarding the thermal spraying temperature conditions at this time, the flame (flame) temperature is 700 to 2500° C., and the spraying speed is 800 to 2000 m/sec.

It should be noted that the temperature was measured at each position of 280 mm, 300 mm, 350 mm, and 450 mm from the front end of the spraying gun on the flame (flame) center line, and the average temperature was taken as the flame (flame) temperature. In addition, for the measurement of the temperature, the injection of the water slurry and the mixing of the air are not performed, and a thermocouple (for example, a SUS material to about 1000°C, and a tungsten/rhenium (W-W·Re) thermocouple for the rest) is used. Conducted by contact with flames. Regarding these aspects, it will be the same in the future.

Fig. 3 is an analysis result of a crystal structure of an X-ray refraction device (XRD) using a photocatalyst film obtained by applying the above-mentioned method for producing a photocatalyst film of the present invention.

Here, in the photocatalyst coating obtained by applying the method for producing a photocatalyst coating of the present invention, when the first peak ratio of FeO(OH) and Fe ₂ O ₃ is adopted, it becomes "FeO(OH):Fe ₂ O ₃ =2.25:1", and the proportion of FeO(OH) contributing to visible light conversion of the photocatalyst is large.

Also, when FeO(OH) is oxidized to form Fe ₂ O ₃ , Fe ₂ O ₃ functions as a co-catalyst but does not contribute to the visible light response characteristics, resulting in deterioration of the visible light response characteristics. However, in the photocatalyst film obtained by applying the method for producing a _{photocatalyst} film _of the present invention, as shown in FIG. Deterioration is suppressed low.

Here, electron micrographs and elemental components of a scanning electron microscope-energy dispersive X-ray analyzer (SEM-EDS) using a photocatalyst coating obtained by the method for producing a photocatalyst coating to which the present invention is applied As a result of the analysis and the distribution analysis of elements, it was found that in the photocatalyst film obtained by the method for producing the photocatalyst film to which the present invention is applied, the contamination of Cl as described below does not exist. This is considered to be because Cl added to the aqueous slurry in an ionic state is volatilized by the heat of spraying and diffuses in the air before reaching the object (substrate), thereby realizing a photocatalyst film with high purity. In addition, b of Table 2 shows the EDS analysis result of the photocatalyst film obtained by the manufacturing method of the photocatalyst film to which this invention was applied.

[Table 2]

FIG. 4 is an analysis result of a crystal structure using XRD of a photocatalyst film obtained by a conventional method for producing a photocatalyst film.

Specifically, the TiO ₂ powder was added to the FeCl ₃ solution in such a way that the Ti component of the rutile titanium dioxide powder (TiO ₂ ) and the Fe component of the ferric chloride aqueous solution (FeCl ₃ ) were Ti:Fe=99:1 by weight. Stirring in medium for 2 hours, so that Fe is supported on TiO ₂ powder. Next, the solution was dried and pulverized, and then classified into particle sizes so that the particle size was about 100 μm. Next, thermal spraying was performed using the water slurry (concentration: 30% by weight) of the produced powder to form a photocatalyst film, and the crystal structure of the photocatalyst film obtained in this way was analyzed by XRD. Figure 4 shows the results . In addition, the manufacturing method of such a photocatalyst film is called a "front loading method" for convenience.

However, in the pre-loading method, that is, pre-immersing and stirring titanium dioxide (TiO ₂ ) in an aqueous solution of ferric chloride (FeCl ₃ ) as a sensitizer, loading iron or an iron compound on titanium dioxide, producing a loaded iron, In the method of the photocatalyst composition of titanium dioxide containing an iron compound, a long time is sometimes required for the treatment and a drying process is added, and it is considered that the possibility of aggregation, growth, segregation, etc. of the iron and the iron compound carried on the surface of the titanium dioxide during this period is high.

On the other hand, in the present invention, the water slurry in which the sensitizer and the antibacterial metal compound are dissolved at the molecular level is instantaneously immobilized on the titanium dioxide surface by sputtering. Therefore, it is considered that the sensitizer, the antibacterial metal compound are The nanometer size is dispersed and carried on the surface of titanium dioxide.

Therefore, it is considered that the sensitizer and antibacterial metal compound of the present invention are very excellent in dispersibility compared with the prior art, so that a higher than expected sensitization effect and antibacterial effect can be obtained.

Here, in the results shown in FIG. 4 , it is known that the peaks of both _FeO (OH) and _Fe2O3 can be observed, and that FeO(OH) contributing to the visible light of the photocatalyst can be utilized at the time of sputtering. Heat is oxidized to form Fe ₂ O ₃ which does not contribute to visible light.

It should be noted that it is known that when the first peak ratio of _FeO (OH) and _Fe2O3 is taken, it becomes "FeO(OH): _{Fe2O3 =} 1.78:1", which is different from the optical peak ratio to which the present invention is applied. Compared with the photocatalyst coating obtained by the method of producing the catalyst coating, the ratio of Fe ₂ O ₃ is large. It should be noted that since the ratio of Fe ₂ O ₃ is large, the visible light responsivity is not sufficient.

Here, the Cl component can be confirmed from the SEM-EDS electron micrograph using the photocatalyst film obtained by the pre-loading method, the component analysis of elements, and the results of distribution analysis of elements. This is considered to be caused by the influence of FeCl ₃ used for Fe loading. That is, it is considered that Cl forms a certain compound during loading and becomes non-volatile due to the heat of spraying, and there is a concern that contamination of such impurities may cause degradation of the photocatalytic properties of the photocatalyst coating. In addition, in a of Table 2, the EDS analysis result of the photocatalyst film obtained by the front loading method is shown.

FIG. 5 is an analysis result of XRD crystal structure using a photocatalyst coating obtained by supporting iron after formation of the titania coating.

Specifically, an aqueous slurry (concentration: 30% by weight) of rutile titanium dioxide powder (TiO ₂ ) was used for thermal spraying to form a TiO ₂ film, and the formed film was expressed as Ti:Fe by weight ratio. =99:1, immersing in the FeCl ₃ solution for 2 hours to load Fe on the TiO ₂ coating, and analyzing the crystal structure of the photocatalyst coating obtained in this way by XRD, and FIG. 5 is the result. In addition, the manufacturing method of such a photocatalyst film is called a "post-loading method" for convenience.

It should be noted that, in the results shown in Fig. 5, no peak of Fe ₂ O ₃ was seen. This is considered to be because FeO(OH) is not affected by heat caused by thermal spraying.

Here, from the results of the SEM-EDS electron micrographs of the photocatalyst film obtained by the post-loading method and the component analysis of the elements and the distribution analysis of the elements, it is known that it is the same as that obtained by the present invention and the front-loading method. Compared with the photocatalyst film, the ratio of Ti and Fe is high. This is considered to be because Fe segregates on the analysis surface due to the characteristics of the loading method after Fe is loaded on the film surface. In such a case, in the case of film formation and abrasion, since Fe does not exist inside the film, there is a concern that the lifetime of the visible light response characteristic may be shortened. In addition, c of Table 2 shows the EDS analysis result of the photocatalyst film obtained by the post-loading method.

From the above, in the case of the front loading method, there are concerns about the following disadvantages: (1) It takes a long time to load on iron; (2) Since the ratio of FeO(OH) is small, the visible light response is poor; (3) The solution at the time of Fe loading exerts a bad influence. In addition, in the case of the post-loading method, there is a concern that Fe segregates on the surface and the lifetime of visible light responsiveness is short.

On the other hand, in the photocatalyst film obtained by the method for producing a photocatalyst film to which the present invention is applied, such defects do not occur, the visible light responsiveness is excellent, and the visible light responsiveness can be extended in life.

In addition, in the method for producing a photocatalyst film to which the present invention is applied, cost reduction is achieved by using titanium dioxide powder with a rutile crystal structure which is cheaper than an anatase crystal structure.

Here, a gas decomposition performance test of the photocatalyst coating was performed.

FIG. 6 shows a conceptual diagram of the evaluation test method. The test piece of the thermal sprayed coating used for evaluation has a square size of about 50 mm, and the ceramic tile was used as a base material. The surface of the test piece was washed with alcohol in advance, and subjected to a pretreatment of irradiating ultraviolet rays (ultraviolet intensity: 1 mW/cm ² ) for 12 hours, and used for an evaluation test of gas decomposition.

Acetaldehyde was used as the gas to be decomposed, and it was adjusted so as to be about 450 ppm in a Tedella sampling bag (125 cc). As a light source, LED light (wavelength 415 nm) was used to irradiate the film surface of the sample with a light intensity of 6 mW/cm ² .

The samples tested were a photocatalyst film obtained by applying the method for producing a photocatalyst film of the present invention and a photocatalyst film obtained by a post-loading method. Furthermore, for comparison, a test was also carried out on a commercially available photocatalyst tile and a sprayed film doped with titanium oxysulfide as a visible light photocatalyst.

7 and 8 show the results of the acetaldehyde gas decomposition test of the respective films. 7 and 8, the photocatalyst film obtained by the method of producing the photocatalyst film to which the present invention is applied exhibits high acetaldehyde gas decomposition activity. In addition, about twice the amount of acetaldehyde was also generated for carbon dioxide, and it is considered that the decomposition proceeded completely.

On the other hand, the photocatalyst film obtained by the post-loading method exhibited the same gas removal performance as that of titanium oxysulfide doped. However, compared with the photocatalyst film obtained by the method for producing the photocatalyst film to which the present invention was applied, the amount of carbon dioxide generated was small, and a sour smell thought to be an intermediate product occurred after the test. Therefore, it is presumed that the gas decomposition reaction at this time was incomplete.

As a result of the gas decomposition test on commercially available photocatalyst tiles, when compared with the photocatalyst film obtained by the method of producing the photocatalyst film to which the present invention is applied, the decomposition activity is quite low.

In addition, the bactericidal effect of the photocatalyst coating was also evaluated.

Fig. 9 shows a conceptual diagram of an evaluation test method. The test piece of the thermal spray coating used for evaluation has a square size of about 50 mm, and a porcelain tile is used as a base material. The surface of the test piece was cleaned with acetone, pretreated with ultraviolet rays (ultraviolet intensity: 1 mW/cm ² ) for 6 hours, and used for an evaluation test of antibacterial activity.

As for the evaluation test method, each sample is placed in a petri dish (90 mm in diameter), 30 ml of a suspension of Escherichia coli is added, and it is kept at 30°C under the irradiation condition (illuminance 1700 lux) of a fluorescent lamp After standing, the number of remaining bacteria was measured over time. In addition, the measurement of the number of bacteria was performed by the colony counting method.

The samples evaluated were a photocatalyst coating obtained by applying the method for producing a photocatalyst coating of the present invention, a sulfur-doped titanium oxide coating, and a commercially available photocatalyst tile. The evaluation test results are shown in FIG. 10 .

From FIG. 10, it is known that the bactericidal power of Escherichia coli with the photocatalyst film obtained by applying the photocatalyst film production method of the present invention shows a reduction of 4 orders in 30 minutes, and 6 orders of sterilization with 180 points. High bactericidal properties of bacteria. In this regard, the bactericidal power of grade 6 in 30 minutes as seen in titanium oxysulfide doped was not achieved, but it can be said to have sufficient performance for practical use. In addition, compared with the blank, the commercially available photocatalyst tile hardly saw the reduction of the number of bacteria, and it was low performance.

<2. Modification 1>

In the method for producing a photocatalyst film to which the above-mentioned present invention is applied, a water slurry using rutile-type titanium dioxide powder and an aqueous solution of ferric chloride may be produced, or an anatase-type titanium dioxide powder and ferric chloride may be used. Water slurries for aqueous solutions. Specifically, for example, an aqueous slurry using anatase-type titanium dioxide powder having a particle diameter of about 10 nm and an aqueous ferric chloride solution can be produced. In this case, in the water slurry, the anatase-type titanium dioxide powder is aggregated to have a particle diameter of about 1 μm to 5 μm.

However, in anatase-type titanium dioxide powder, it is difficult for the excited electrons excited by visible light to exceed the band gap, and it is difficult to produce visible light responsiveness. Type crystal structure and then apply it to the object. Specifically, it is necessary to form a photocatalyst coating by changing the crystal structure of the titanium dioxide powder into a rutile type by heat at the time of thermal spraying at a flame temperature of 2000° C. or higher. Therefore, when FeO(OH) is supported, it is preferable not to use expensive anatase-type titanium oxide, but to use rutile-type titanium oxide from the beginning.

＜3. Modification 2＞

In the method for producing a photocatalyst film to which the above-mentioned present invention is applied, a case in which FeO(OH) exhibiting a visible light response function is supported on rutile-type titanium dioxide powder to realize a visible light responsive photocatalyst film will be described as an example. .

However, what is carried on the photocatalyst particle does not need to be limited to the substance which exhibits a visible light response function, _Fe2O3 etc. which exhibit a co-catalyst function may be _sufficient .

Specifically, for example, it is possible to produce a water slurry using anatase-type titanium dioxide powder having a particle diameter of about 10 nm and an aqueous solution of ferric chloride (at this time, anatase-type titanium dioxide powder aggregates in the water slurry to form 1 μm to 5 μm in particle size), the photocatalyst film is formed by laminating anatase-type titanium dioxide loaded with Fe ₂ O ₃ that exhibits a cocatalyst function by sputtering using the generated aqueous slurry .

Regarding the thermal spraying temperature conditions at this time, the flame temperature is 300 to 2000° C., and the thermal spraying speed is 800 to 2000 m/sec.

It should be noted that anatase-type titanium dioxide can exhibit higher catalytic activity than rutile-type titanium dioxide.

＜4. For loading of silver＞

In one example of the manufacturing method of the photocatalyst film of the present invention applied above, by using the aqueous slurry that adopts titanium dioxide powder and ferric chloride aqueous solution to carry out thermal spraying, the oxide that supports iron, hydroxide The case of forming a titanium dioxide film in at least one form of iron or oxyhydroxide is described as an example. It is also possible to support not only iron but also silver oxides, hydroxides, and oxyhydroxides. Various forms of titanium dioxide film were formed.

Specifically, for example, Ti component of titanium dioxide powder (TiO ₂ ) and Fe component of ferric chloride aqueous solution (FeCl ₃ ) can be Ti:Fe=99.7:0.3 in weight ratio, and titanium dioxide powder (TiO ₂ ) and the Ag component of the silver nitrate aqueous solution (AgNO ₃ ) in a weight ratio of Ti:Ag=99:1 to generate a water slurry using rutile-type titanium dioxide powder, ferric chloride aqueous solution, and silver nitrate aqueous solution (concentration: 30% by weight), thermal spraying was performed using the produced water slurry to form a photocatalyst film.

By forming the film in this way, silver oxide (AgO ₂ ), which is a kind of antibacterial metal, is supported on the rutile-type titanium dioxide film having a visible light response function and a co-catalyst function, thereby enabling the photocatalyst film to also bear extremely High antibacterial function, if applied to floor materials, wall materials, ceiling materials, incidental equipment, etc. in hospitals, nursing facilities for the elderly, food processing factories, etc. Effective.

Here, from the SEM-EDS surface observation results (not shown) of the photocatalyst film obtained by the method for producing the photocatalyst film using the above-mentioned photocatalyst film, it can be seen that the nano-sized silver oxide does not segregate, and is almost uniformly distributed. to disperse. In addition, the stable antibacterial effect can be produced by dispersing|distributing the oxide of silver substantially uniformly.

However, surface observation by SEM-EDS using the photocatalyst film obtained by the front loading method was performed.

Specifically, the TiO ₂ powder was stirred in the FeCl ₃ solution so that the Ti component of the titanium dioxide powder (TiO ₂ ) and the Fe component of the ferric chloride aqueous solution (FeCl ₃ ) were Ti:Fe=99.7:0.3 by weight. For 2 hours, Fe was supported on the TiO ₂ powder. Next, the silver nitrate aqueous solution was added to the solution so that the Ti component of the titanium dioxide powder (TiO ₂ ) and the Ag component of the silver nitrate aqueous solution (AgNO ₃ ) were Ti:Ag=99:1 by weight. Stirring is carried out to further support Ag on the TiO ₂ powder. Next, this solution was dried and pulverized, and then classified into particle diameters to make the particle sizes uniform. Next, a photocatalyst film was formed by thermal spraying using an aqueous slurry (concentration: 30% by weight) of the prepared powder, and surface observation by SEM-EDS using the photocatalyst film thus obtained was performed.

As a result, it was found that silver segregation of 3 μm or more was present. It should be noted that when silver is segregated, the photocatalyst function and antibacterial effect vary depending on the location, and the performance of the photocatalyst coating is unstable.

In addition, surface observation by SEM-EDS using the photocatalyst film obtained by the post-loading method was performed.

Specifically, a titanium dioxide powder (TiO ₂ ) water slurry (concentration: 30% by weight) was used for thermal spraying to form a TiO ₂ film, and the formed film was expressed as Ti:Fe= 99.7:0.3 method was immersed in the FeCl ₃ solution for 2 hours to load Fe on the TiO ₂ film. Next, it was immersed in an aqueous solution of silver nitrate so that the weight ratio was Ti:Ag=99:1, irradiated with ultraviolet rays, and Ag was supported on the TiO ₂ film, and SEM-EDS using the photocatalyst film obtained in this way was carried out. Superficial observation. 11 and 12 show the results of the gas decomposition test and the sterilization test using the film.

As a result, it was found that silver segregation of 3 μm or more was present. It should be noted that when silver is segregated, the photocatalyst function and antibacterial effect vary depending on the location, and the performance of the photocatalyst coating is unstable.

In addition, the existence of thick segregation of silver was confirmed on the surface layer of the film, and such segregation of silver on the surface layer causes a decrease in the intensity of light reaching the titanium dioxide, and there is a concern about a decrease in photocatalytic performance.

It should be noted that, from Fig. 11, it can be seen that it takes 120 minutes to decompose 300 ppm of acetaldehyde. In addition, carbon dioxide was also generated in a large amount, and it was confirmed that the decomposition was complete. Furthermore, from FIG. 12 , it was found that 10 ⁶ cfu/mL of Escherichia coli was reduced to 0 in 180 minutes, showing high bactericidal performance.

＜5. For loading of pigments＞

In one example of the production method of the photocatalyst film to which the above-mentioned present invention is applied, a titanium dioxide film carrying iron is formed by thermal spraying using an aqueous slurry using titanium dioxide powder and an aqueous ferric chloride solution. The case will be described as an example, but it is also possible to form a titanium dioxide film on which not only iron but also a pigment is supported. It is to be noted that the photocatalyst film can be colored by supporting the pigment, and the color changes according to the degree of the pigment adhesion.

Here, FIG. 13 shows that the Ti component of the titanium dioxide powder (TiO ₂ ) and the pigment (the components are mica (muscovite), TiO ₂ , and Fe ₂ O ₃ ) are Ti:pigment=7:3 by weight ratio. Analysis results of the XRD crystal structure of the photocatalyst film formed by generating water slurry (concentration: 30% by weight) and thermal spraying using the generated water slurry.

From the results shown in FIG. 13 , it was found that the peak of Fe ₂ O ₃ was small and the adhesion ratio of the pigment was small.

Here, from the results (not shown) of the SEM-EDS electron micrographs of the photocatalyst film obtained by the above-mentioned method and the component analysis of the elements and the distribution analysis of the elements (not shown), it is known that it is consistent with the above-mentioned Compared with the case of loading, the yield of the pigment is low.

FIG. 14 is an analysis result of the XRD crystal structure using the photocatalyst film obtained by the front loading method.

Specifically, the Ti component of titanium dioxide powder (TiO ₂ ) and the pigment were mixed so that the weight ratio of Ti:pigment=7:3, the two powders were mixed, fired at 1200° C. for 30 minutes, and the obtained pellets were processed. Pulverize and classify the particle size so that the particle size is about 100 μm. Next, thermal spraying was performed using an aqueous slurry (concentration: 30% by weight) of the prepared powder to form a photocatalyst film, and the crystal structure of the thus obtained photocatalyst film was analyzed by XRD, and FIG. 14 is the result.

From the results shown in FIG. 14 , it was found that the peak of Fe ₂ O ₃ , which is a pigment component, was large, and many pigments were attached.

Here, from the results (not shown) of the SEM-EDS electron micrographs of the photocatalyst film obtained by the above-mentioned pre-loading method and the component analysis of the elements and the distribution analysis of the elements (not shown), it is known that: Fe is about 16% of Ti, and the yield of pigment is high. This is considered to be because the mass of the particles increased due to the composite of the pigment and TiO ₂ .

Fig. 15 is an analysis result of the crystal structure by XRD using the photocatalyst film obtained by the post-loading method.

Specifically, thermal spraying was performed using an aqueous slurry (concentration: 30% by weight) of titanium dioxide powder (TiO ₂ ) to form a TiO ₂ film. Next, the pigment was formed into a water slurry (concentration: 30% by weight), coated on the _TiO2 film, and then fired at 1250°C for 1 hour, and the crystal structure of the composite film of _TiO2 and pigment thus obtained was determined by XRD. Analysis, Figure 15 is its result.

From the results shown in FIG. 15 , it is considered that there is no peak of TiO ₂ and that the pigment covers the surface above the penetration depth of X-rays.

Here, from the SEM-EDS electron micrograph of the photocatalyst film obtained by the above-mentioned post-loading method, the results of component analysis of elements and distribution analysis of elements (not shown), it is known that the ratio of Ti Very low, the pigment completely coats the surface. Such a pigment causes a decrease in the intensity of light reaching titanium dioxide, and there is a concern about a decrease in the photocatalyst function.

Claims (6)

1. a manufacture method for photochemical catalyst tunicle, it possesses:

Form the operation containing at least a kind of compound of rutile titanium dioxide particle, the water-soluble metal complexes being selected from Fe, Cu, Cr, Ni or water-soluble metal salt and the slurry of water;

Described slurry is carried out spraying plating at flame temperature 700 ~ 2500 DEG C, the anion of at least a kind of described compound is volatilized by the heat of spraying plating, oxygen in the water of the metal ion of described compound and described slurry and air is reacted generate, present visible light-responded function and co-catalyst function, Fe, Cu, Cr, the hydroxide of Ni or at least a kind of form of oxyhydroxide, and generate together with described hydroxide or described oxyhydroxide, present visible light-responded function and co-catalyst function, Fe, Cu, Cr, at least a kind of form of the oxide of Ni supports the rutile titanium dioxide particle in described slurry, the simultaneously operation of this rutile titanium dioxide particle stacked on object.

2. the manufacture method of photochemical catalyst tunicle as claimed in claim 1, wherein, with regard to the operation of described stacked rutile titanium dioxide particle on object, slurry described in spraying plating at flame temperature 2000 ~ 2500 DEG C.

3. the manufacture method of photochemical catalyst tunicle as claimed in claim 1 or 2, wherein,

Described slurry is formed containing at least one being selected from antibacterial metal, antibacterial metal salts or antibacterial metal complex,

Described slurry is carried out spraying plating and to be selected from form stacked described antibacterial metal, antibacterial metal salts or antibacterial metal complex on object of at least one in metal, slaine, metal complex, oxyhydroxide, hydroxide or oxide together with described rutile titanium dioxide particle.

4., as the manufacture method of photochemical catalyst tunicle according to claim 1 or claim 2, wherein, form described slurry containing pigment, described slurry is carried out spraying plating and together with described rutile titanium dioxide particle on object stacked pigment.

5., as the manufacture method of photochemical catalyst tunicle according to claim 1 or claim 2, wherein, form described slurry containing sorbing material, described slurry is carried out spraying plating and together with described rutile titanium dioxide particle on object stacked sorbing material.

6. a photochemical catalyst tunicle, it manufactures as follows:

Formed containing at least a kind of compound of rutile titanium dioxide particle, the water-soluble metal complexes being selected from Fe, Cu, Cr, Ni or water-soluble metal salt and the slurry of water;

Described slurry is carried out spraying plating at flame temperature 700 ~ 2500 DEG C, the anion of at least a kind of described compound is volatilized by the heat of spraying plating, oxygen in the water of the metal ion of described compound and described slurry and air is reacted generate, present visible light-responded function and co-catalyst function, Fe, Cu, Cr, the hydroxide of Ni or at least a kind of form of oxyhydroxide, and generate together with described hydroxide or described oxyhydroxide, present visible light-responded function and co-catalyst function, Fe, Cu, Cr, at least a kind of form of the oxide of Ni supports the rutile titanium dioxide particle in described slurry, this rutile titanium dioxide particle stacked on object simultaneously.