JP5167482B2 - Composite porous body and method for producing the same - Google Patents

Description

  The present invention relates to a composite porous body, particularly a composite porous body useful for environmental purification and removal of harmful substances in water, and a method for producing the same.

  As interest in environmental issues increases and environmental conservation on a global scale is called out, various hazardous chemical substances that are disposed of along with industrial activities have become a problem. Examples of the harmful chemical substances include endocrine disrupting substances (hereinafter referred to as environmental hormones) and persistent substances such as organochlorine compounds, and these are detected from the water environment such as rivers. In particular, alkylphenol groups such as nonylphenol, which is an environmental hormone, have endocrine disrupting properties even in trace amounts, and there is concern about the impact on the ecosystem. In view of such a situation, it is required to perform high-performance purification in a wastewater treatment and purification process to remove these substances.

In such a flow, the solid medium is not provided after the porous body is formed, but before the porous skeleton is formed, the raw material of the porous body or a synthetic medium such as a solution, sol, or gel that forms the porous body It is reported that a composite porous body having a good organic substance adsorption and decomposition function can be produced by mixing solid fine particles into a solid body to form a porous body containing solid fine particles (see, for example, Patent Document 1). ).
Japanese Patent Laying-Open No. 2005-314208 (published on November 10, 2005)

  However, the composite porous body obtained by the production method described in Patent Document 1 has a problem in that it has a large number of pores that do not communicate with titanium oxide and the selectivity is not sufficient. Therefore, a composite porous body having higher molecular selectivity is desired.

  This invention is made | formed in view of said problem, The objective is to implement | achieve the composite porous body which has high molecular selectivity, and its manufacturing method.

  In order to solve the above problems, the method for producing a composite porous body according to the present invention, in the method for producing a composite porous body forming a composite porous body in an aqueous surfactant solution, before the skeleton of the porous body is generated, A step of mixing and dispersing solid fine particles in an aqueous surfactant solution, a step of mixing ethanol in an aqueous surfactant solution before the porous skeleton is formed, and an aqueous solution in which solid fine particles are dispersed; And a step of forming a composite porous body in which the porous body and the solid fine particles are composited by generating a skeleton.

  According to the above method, before the porous skeleton is formed, ethanol is mixed in the surfactant aqueous solution, and the solid fine particles are mixed and dispersed so that the porous material and the solid fine particles are combined. Form the body. For this reason, a composite porous body having three-dimensional pores and a composite of a porous body and solid fine particles can be manufactured. Therefore, the composite porous body having high molecular selectivity can be produced.

  In the manufacturing method of the composite porous body which concerns on this invention, it is preferable to perform the process of forming a composite porous body at the temperature below the Kraft point of the said surfactant.

  According to the above method, it is possible to suppress the release of the surfactant from the micelles and the reconstruction of the micelles, and the micelles formed in the surfactant aqueous solution can be more regularly arranged. In addition, the composite porous body formed in the surfactant aqueous solution hardly deteriorates. Thereby, the composite porous body which has a more uniform structure can be manufactured. Therefore, the composite porous body having higher molecular selectivity and decomposition rate with respect to the organic substance can be produced.

  In the method for producing a composite porous body according to the present invention, the solid fine particles are preferably titanium dioxide.

  According to the above method, a composite porous body having a higher decomposition rate can be produced.

  Moreover, in the manufacturing method of the composite porous body which concerns on this invention, it is preferable to mix the said ethanol in the said aqueous solution within the range of 0.05-0.5 with respect to the water 1 by volume ratio.

  According to the above method, it is possible to produce a composite porous body having a higher ratio of three-dimensional pores and a composite of a porous body and solid fine particles.

  In the method for producing a composite porous body according to the present invention, the surfactant is preferably a cationic surfactant.

  Moreover, in the manufacturing method of the composite porous body which concerns on this invention, it is preferable that the said cationic surfactant is CTAB (cetyl trimethyl ammonium bromide).

  In the method for producing a composite porous body according to the present invention, the porous body is preferably at least one porous body selected from porous silica, zeolite, porous alumina, and porous silica alumina.

  According to the above method, a composite porous body having higher molecular selectivity and decomposition rate for environmental purification and removal of harmful substances in water can be produced.

  In the method for producing a composite porous body according to the present invention, the porous body is preferably mesoporous silica.

  According to the above method, a composite porous body having higher molecular selectivity and decomposition rate for environmental purification and removal of harmful substances in water can be produced.

  In the method for producing a composite porous body according to the present invention, the porous body is preferably MCM-48 type mesoporous silica.

  According to the above method, a composite porous body having higher molecular selectivity and decomposition rate for environmental purification and removal of harmful substances in water can be produced.

  In the method for producing a composite porous body according to the present invention, the solid fine particles are preferably modified with an organic compound.

  According to the above method, since the solid fine particles are uniformly contained in the porous body, it is possible to produce a composite porous body in which the porous body and the solid fine particles are complexed with a higher ratio of three-dimensional pores.

  In order to solve the above problems, a composite porous body according to the present invention is manufactured by the above-described method for manufacturing a composite porous body according to the present invention.

  According to the above configuration, the composite porous body in which the porous body and the solid microparticles are combined by mixing ethanol in the surfactant aqueous solution before the porous body skeleton is generated and mixing and dispersing the solid microparticles. To form. For this reason, it becomes a composite porous body in which the porous body and the solid fine particles have a composite structure with three-dimensional pores. Therefore, the composite porous body having high molecular selectivity can be provided.

  As described above, the method for producing a composite porous body according to the present invention is the method for producing a composite porous body that forms a composite porous body in an aqueous surfactant solution. The step of mixing and dispersing the solid fine particles in the aqueous solution, the step of mixing ethanol in the surfactant aqueous solution before the porous skeleton is formed, and the porous skeleton in the aqueous solution in which the solid fine particles are dispersed. And a step of forming a composite porous body in which the porous body and solid fine particles are combined to form a composite porous body.

  For this reason, there exists an effect that the composite porous body which has high molecular selectivity can be manufactured.

  In order to solve the above problems, a composite porous body according to the present invention is manufactured by the above-described method for manufacturing a composite porous body according to the present invention.

  For this reason, there exists an effect that the composite porous body which has high molecular selectivity can be provided.

  The present invention will be described in detail below. In this specification, “weight” is treated as a synonym for “mass”, and “weight%” is treated as a synonym for “mass%”. In addition, “A to B” indicating a range indicates that the range is A or more and B or less.

  The method for producing a composite porous body according to the present embodiment is a method for producing a composite porous body that forms a composite porous body in a surfactant aqueous solution, and before the skeleton of the porous body is generated, in the surfactant aqueous solution. A step of mixing and dispersing solid fine particles (hereinafter sometimes simply referred to as “mixing and dispersing step”), and a step of mixing ethanol in an aqueous surfactant solution (hereinafter, referred to as “mixing and dispersing step”). In some cases, simply referred to as “ethanol mixing step”), a porous body and a solid fine particle are combined to form a composite porous body by forming a porous skeleton in the aqueous solution in which the solid fine particles are dispersed. Process (hereinafter may be simply referred to as “formation process”).

(1) Mixing and dispersing step In the mixing and dispersing step, solid fine particles are mixed and dispersed in a surfactant aqueous solution. Solid fine particles forming the porous body and the composite porous body include magnesia, alumina, silica, aluminum phosphate, boron, carbon, silicon nitride, aluminum nitride and other inorganic oxides, chlorides, nitrides, borides, carbides. In addition to sulfides, organic particles such as resin particles such as polyethylene can be used, and fine particles having a photocatalytic function are particularly preferable.

As the fine particles having a photocatalytic function (hereinafter sometimes referred to as “photocatalyst fine particles”), any substance having a characteristic as a semiconductor and having a photocatalytic characteristic can be used. Among these, metal sulfides and metal oxides are preferable, and metal oxides such as titania, zirconia, niobium oxide, and tungsten oxide are most preferable. Specifically, TiO ₂ , SrTiO ₃ , WO ₃ , Fe ₂ O ₃ , Bi ₂ O ₃ , MoS ₂ , CdS, CdSe, GaP, GaAs, MoSe ₂ , CdTe, Nb ₂ O ₅ , Ta ₂ O ₅ , In addition to complex oxides of Nb and Ta, heteropolyacids such as H ₃ PW ₁₂ O ₄₀ and H ₃ PMo ₁₂ O ₄₀ and salts thereof can be used. Among these, TiO ₂ (titanium dioxide), which is known to have high photocatalytic activity, is more preferable. In addition, as photocatalyst particles, it is more preferable to use fine particulate TiO ₂ that is not aggregated (for example, P-25 manufactured by Degussa, Germany).

  The solid fine particles preferably form pores having an average particle diameter of 2 nm or more and 50,000 nm or less. As a minimum, 5 nm or more is more preferable, and 10 nm or more is still more preferable. As an upper limit, 5,000 nm or less is more preferable, and 1,000 nm or less is still more preferable.

  If the average diameter of the solid fine particles is smaller than the above range, the crystallinity of the fine particles is deteriorated and the photocatalytic activity is lowered. When the average diameter of the solid fine particles is larger than the above range, the surface area of the fine particles becomes small, so that the catalytic activity becomes low.

  The addition ratio of the solid fine particles is preferably 10% by weight or more, more preferably 20% by weight or more, and more preferably 50% by weight or more based on the total amount of the porous material and the solid fine particles. Is more preferable. As an upper limit, it is more preferable to set it as 98 weight% or less, and it is still more preferable to set it as 95 weight% or less. By setting the addition ratio of the solid fine particles within the above range, the solid fine particles exhibit a good and effective function.

  When the solid fine particles are photocatalyst particles, if the content is 10% by weight or less, the ability to convert the organic material of the composite porous body is not sufficient, and the removal of harmful organic materials and the synthesis of useful materials can be sufficiently performed. Absent. Moreover, even if it contains more photocatalyst particles than the said range, since an effect cannot be improved more than it, it is more preferable to make it smaller than the said upper limit from the surface of cost.

  The solid fine particles are more preferably modified with an organic compound. In the present specification, the “organic compound” may be a compound having catalytic activity or a compound having no catalytic activity. In the present embodiment, the organic compound preferably has a functional group that can act in cooperation with the inorganic catalyst component, and more preferably covalently bonded onto the solid fine particles.

  The method for covalently bonding the organic compound onto the solid fine particles is not particularly limited, and examples thereof include silane coupling. For the silane coupling, a known silane coupling agent as described in JP-A-2006-198503 may be used.

As the silane coupling agent, for example, n- dodecyl triethoxy silane _{(CH 3 (CH 2) 11} Si (OC 2 H 5) 3), n- octadecyl triethoxysilane _{(CH 3 (CH 2) 17} Si ( _{OC 2 H 5) 3),} 3- aminopropyltriethoxysilane _{(NH 2 (CH 2) 3} Si (OC 2 H 5) 3), 3- chloropropyltriethoxysilane _{(Cl (CH 2) 3 Si} (OC ₂ H _{5) 3),} 3- bromo-butyl triethoxysilane _{(Br (CH 2) 4 Si} (OC 2 H 5) 3) , and the like.

  Among the silane coupling agents, compounds having a long chain alkyl group such as n-dodecyltriethoxysilane, n-octadecyltriethoxysilane, etc. adsorb reactive molecules having a hydrophobic group in a molecular recognition manner. Change adsorption orientation and reaction selectivity. In the case of an organic group having a chloro or amino group, the solid fine particles act as an electron donating or electron withdrawing to change the activity and / or selectivity of the solid fine particles such as catalytic activity. In the case of an organic group having a phenolic hydroxyl group or amino group, it interacts with a carbonyl group in the reaction molecule to change its reactivity.

  The type of the surfactant is not particularly limited, and any type of surfactant such as a nonionic surfactant, an anionic surfactant, and a cationic surfactant may be used, and synthesis of mesoporous silica. Various surfactants used in the above can be used. This includes anionic surfactants such as alkylbenzene sulfonates and block copolymer surfactants (for example, BASF P123 frequently used in the synthesis of mesoporous silica called SBA-15). However, it is more preferable to use a cationic surfactant. As the cationic surfactant, since the pore diameter can be changed by changing the carbon number of the linear alkyl group, the carbon number of the linear alkyl group can be selected according to the target pore diameter, and is not particularly limited. In order to obtain a more regular pore structure, a cationic surfactant in which the linear alkyl group has approximately 2 to 24 carbon atoms is more preferable, and a cationic interface in which the linear alkyl group has 8 to 18 carbon atoms. Activators are more preferred, with CTAB (cetyltrimethylammonium bromide) being particularly preferred.

  The concentration of the surfactant in the aqueous surfactant solution is not particularly limited, and is preferably in the range of 0.5 to 30% by weight, more preferably in the range of 2 to 10% by weight.

  The raw material of the porous body may be added to the surfactant aqueous solution before mixing the solid fine particles, or may be added after mixing the solid fine particles.

  The raw material of the porous body is not particularly limited as long as it forms a porous body, such as a metal alkoxide such as tetraethoxysilane, a metal salt such as sodium silicate, and other metal acetates and acetylacetone complexes. Examples thereof include organometallic compounds and sols and gels containing these.

  Also, solid fine particles such as metal oxides can be used as the porous material. Unlike fine particles to be combined, these fine particles are once dissolved in an aqueous surfactant solution and become a raw material for forming a porous skeleton.

  In addition, as a raw material of the porous body, a porous body made of a metal oxide, a porous body made of porous silica, zeolite, porous alumina, silica alumina, etc., or a material that can form a porous body made of a mixture thereof In particular, those that form a porous body of silica alumina are preferred. Among these, a mesoporous material is particularly preferable. The reason is that the pore diameter is uniform and the molecular selectivity for adsorbing specific molecules is easily developed.

  In addition, in a mixing process, you may add another solvent, the acid for adjusting pH, a base, etc. in addition to this.

  The method of mixing and dispersing the solid fine particles in the surfactant aqueous solution is not particularly limited. For example, the solid fine particles are added to the surfactant aqueous solution and then sufficiently stirred, or ultrasonic waves are added to the surfactant aqueous solution. And a method of mixing and dispersing.

(2) Ethanol mixing step In the ethanol mixing step in the present embodiment, ethanol is mixed in the surfactant aqueous solution. In this case, in addition to ethanol, other alcohols such as methanol and propanol may be contained. However, as described later in Examples, in the case of alcohol having a large hydrophobicity such as propanol, it is considered that alcohol molecules destroy the structure of micelles, and the product when propanol is added is only ethanol. The proportion of lamellar structure is increased compared to the product of

  When methanol is added, since methanol is less hydrophobic than ethanol, alcohol molecules cannot efficiently enter between the hydrophobic and hydrophilic parts of the surfactant, but the formation of lamellar structures is suppressed. Is done.

  Therefore, as alcohol mixed with the surfactant aqueous solution, ethanol and methanol, or ethanol alone is more preferable. However, since methanol is more toxic than ethanol, it is more preferable to use only ethanol from the viewpoint of the safety of the synthesis operation.

  The ratio of ethanol mixed in the surfactant aqueous solution is not particularly limited, but is more preferably in the range of 0.05 or more and 0.5 or less with respect to water 1 by volume ratio, and 0.149 or more. More preferably, it is within the range of 0.189 or less. As a result, a composite porous body in which a porous body and solid fine particles are combined with a higher ratio of three-dimensional pores can be manufactured.

  In addition, the said ethanol mixing process may be performed before the mixing dispersion process mentioned above, may be performed after it, and may be performed simultaneously.

(3) Formation step The formation step is a step of forming a composite porous body in which the porous body and the solid fine particles are combined by generating a skeleton of the porous body in an aqueous surfactant solution in which the solid fine particles are dispersed.

The method for forming the composite porous body is not particularly limited. For example, (i) a method of adding and mixing the porous material to the surfactant aqueous solution, (ii) after adding and mixing the porous material to the surfactant aqueous solution , A method of performing hydrothermal treatment using an autoclave, etc., and (iii) forming a composite porous body so that the porous body wraps around the TiO _{2 in} a spherical shape by adding and mixing the porous body material to the surfactant aqueous solution (first And the like, and a method of performing hydrothermal treatment using an autoclave or the like after further adding and mixing the porous material to the aqueous surfactant solution. Among these, the method (i) is more preferable because a composite porous body having a uniform structure can be produced.

  The solution temperature in the first step in the above method (i) and (iii) is not particularly limited, but is preferably a temperature below the Kraft point of the surfactant to be used. Thereby, it is considered that the release of the surfactant from the micelles and the remodeling of the micelles can be suppressed, and the micelles formed in the surfactant aqueous solution can be more regularly arranged. Therefore, a composite porous body having a more uniform structure can be obtained. The lower limit of the solution temperature is not particularly limited as long as no dissolution of the dissolved matter occurs, but it is more preferably at least 10 ° C. lower than the Kraft point.

  The treatment temperature in the second stage hydrothermal treatment in the method (ii) and the method (iii) is such that the solution temperature is 60 ° C. or higher, and more preferably in the range of 80 to 150 ° C.

  The obtained composite porous body is more preferably baked to remove organic substances and templating agents. At this time, the time and temperature for heating and firing may be appropriately set so that the porous body can be formed satisfactorily. For example, the temperature of the porous material may be 150 ° C. or higher, more preferably 250 ° C. or higher. Further, the upper limit may be 1,000 ° C. or lower, more preferably 800 ° C. or lower. The firing time is preferably about 1 to 10 hours.

(4) Composite porous body The composite porous body manufactured by the manufacturing method described above includes three-dimensional pores. Moreover, even if the content ratio of the solid fine particles is large, the pores of the porous body are maintained, and the crystals of the solid fine particles are not broken. Accordingly, the composite porous body not only exhibits functions such as conversion of organic substances but also has high molecular selectivity. Moreover, since the pore structure of the porous body is not broken, it has a function of adsorbing organic substances satisfactorily.

  The composite porous body preferably has an average pore diameter of 0.5 nm to 100 nm. As a minimum, 1 nm or more is more preferable, and 1.5 nm or more is still more preferable. As an upper limit, 50 nm or less is more preferable, and 10 nm or less is still more preferable. Even if the average diameter of the pores of the porous body is smaller or larger than the above range, the organic substance cannot be favorably adsorbed.

  If relatively small molecules such as those used in the examples described later are to be adsorbed, a porous body having pores having a diameter in the range of 0.5 nm to 500 nm, more preferably 1 nm to 50 nm is usually used. It is done. From the viewpoint of promoting the diffusion of the solution and securing the flow path, it is advantageous to include a larger pore than the above. In addition to the above-mentioned pore, a large pore having a diameter of 1 μm or more is advantageous. A porous body can also be used.

  In addition, since the composite porous body manufactured by the above manufacturing method usually includes a porous body and solid fine particles larger than the pore diameter of the porous body, the contact area of the solid fine particles with the porous body is small. However, more solid fine particles can be supported on the porous body. Further, when the solid fine particles are larger than the pore diameter of the porous body, the solid fine particle crystals are smaller than the conventional case where the solid fine particles having a particle size smaller than the pores of the porous body are coated in the pores of the porous body. Since the effect on the structure is small, the function of the solid fine particles can be exhibited well.

  In this case, the diameter of the porous pores is preferably 0.5 nm to 100 nm in average diameter, and the average particle size of the solid fine particles is preferably 2 nm to 50,000 nm. More preferably, the diameter is from 1 nm to 100 nm, and the average particle size of the solid fine particles is from 10 nm to 500 nm. Thereby, solid fine particles can be favorably supported.

  And the said composite porous body can convert the organic substance in a sample liquid by irradiating the light of the wavelength range which activates a solid fine particle, contacting a sample liquid. Thereby, harmful organic substances contained in the sample liquid can be removed, and useful substances can be synthesized from the organic substances contained in the sample liquid.

  Furthermore, the selective adsorption ability of the porous body may be enhanced by selectively binding to a specific organic substance or imparting an organic group with high affinity to the surface of the porous body.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. Embodiments are also included in the technical scope of the present invention.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to a following example. In addition, the density | concentration of the ammonia water used in the Example is 28 volume%, and ethanol is 99.5 volume%.

In this embodiment, the following abbreviations may be used for convenience.
TEOS: Tetraethyl Ortho Silicate (Tetra Ethyl Ortho Silicate Si (OC ₂ H ₅ ) ₄ )
CTAB: Cetyl trimethyl ammonium bromide
PH: phenol NPP: n-propylphenol NHP: n-hexylphenol NP: nonylphenol PT: paratoluidine NBA: n-butylaniline NHA: n-heptylaniline <Decomposition experiment with composite porous body>
The composite porous body was subjected to decomposition experiments in phenol, aniline, and dye systems, and the catalytic function of each sample was examined.

(1) Phenol-based decomposition experiment An aqueous solution containing 1.5 × 10 ⁻⁵ mol / L of PH, NPP, NHP, and NP was prepared, and 300 mL was weighed with a graduated cylinder and poured into a beaker (300 mL). Analysis was performed by liquid chromatography (LC) every 30 minutes, and it was confirmed that the measured values were almost constant. 30 mg of the composite porous material was taken and added to a beaker containing the solution. Analysis by LC was performed every 30 minutes, and it was confirmed that the adsorption of organic matter to the composite porous body was constant. Ultraviolet rays were irradiated (xenon lamp), the solution was sampled at regular intervals, analyzed by LC, and the change with time of the organic substance concentration in the solution was traced.

(2) Aniline-based decomposition experiment An aqueous solution containing 2.5 × 10 ⁻⁵ mol / L of PT, NBA, and NHA was prepared, and an experiment similar to the above “phenol-based decomposition experiment” was performed.

(3) Dye-based decomposition experiment An aqueous solution containing 2.6 × 10 ⁻⁶ mol / L of rhodamine B and methylene blue was prepared, and 300 mL was weighed with a graduated cylinder and poured into a beaker (300 mL). 30 mg of the composite porous material was taken and added to a beaker containing the solution. Ultraviolet rays were irradiated (xenon lamp), the solution was sampled at regular intervals, and the change with time was examined by tracing the peak of the maximum absorption wavelength with a UV / Vis spectrophotometer. The decomposition rate was calculated from the difference between the analysis values at the start of the reaction and 10 minutes after the start of the reaction.

[Powder X-ray diffraction measurement (XRD)]
The powdery composite porous body was placed on a glass cavity and measured under the following conditions.
<Devices used>
Powder X-ray diffractometer M18XHF-SRA manufactured by Mac Science Co., Ltd.
<Measurement conditions>
Measurement method: Continuous scan method
Rotating cathode: Cu Kα1 λ = 1.5405Å
Measurement range: 2θ 1.5-10
Sampling interval: 0.0060 degree
Scan speed: 1.5000 deg / min
X-ray tube voltage: 40 kV
X-ray tube voltage: 150 mA
Divergence slit: 0.50deg
Scattering slit: 0.50 deg
Light receiving slit: 0.15 mm
Graphite monochromator (nitrogen adsorption measurement)
About 30 mg of the composite porous body was taken, vacuum-heated (200 ° C.) and exhausted, and then the specific surface area and pore volume of the composite porous body were measured by a nitrogen adsorption measurement device (Nippon Bell Co., Ltd. high-precision gas adsorption device BELSORP-mini). And the pore diameter were determined.
<Measurement conditions>
Measurement method: Constant volume gas adsorption method Adsorption gas: Nitrogen pretreatment conditions: Vacuum exhaust measurement program at 200 ° C for 2 hours: Adsorption / desorption isotherm measurement analysis program: Adsorption / desorption isotherm measurement
Specific surface area by BET method
Initial introduction amount of pore size distribution by DH, BJH method: 1.5 cm ³ · g ⁻¹
Measurement phase pressure range: 0 to 1.0
Sample amount: about 30mg
[Liquid chromatograph measurement]
The liquid chromatograph measurement was performed under the following conditions.
<Devices used>
Shimadzu Liquid Chromatograph LC-10AD
<Measurement conditions>
Mobile phase: acetonitrile / water mixed solution mobile phase flow rate: 1 cc / min
Absorption detection wavelength: 220 nm
Column temperature: 40 ° C
[UV / Vis absorption spectrum analysis]
The UV / Vis absorption spectrum was measured under the following conditions.
<Devices used>
Lambda 900 made by PERKIN ELMER
<Measurement conditions>
Slit: 2nm
Integration Time: 0.20sec
Scanspeed: 500nm / min
Gain: 1
Measurement range: 800-270 nm
[SEM image observation]
In order to observe the outer surface of the composite porous body, a scanning electron microscope (Lambda 900 manufactured by PERKIN ELMER) was used. As a preparatory preparation, the composite porous body was adhered on a carbon tape affixed to a sample stage and observed after platinum deposition.

[TEM image observation]
In order to observe the inside of the composite porous body, a transmission electron microscope (ELECTRON MICROSCOPE JEM-2010, JEOL Ltd.) was used. As a preparatory preparation, the composite porous material was dispersed in acetone and dropped onto the grid mesh.

[Reference Examples 1-43]
In order to synthesize a composite porous body of MCM48 type mesoporous silica (hereinafter sometimes simply referred to as “MCM48”) and TiO ₂ , synthesize MCM48 by a method that can be combined with TiO _2. is necessary.

  A normal temperature synthesis method of MCM48 is described in literature (D. Kumar et al, Coll. Surf. A, 187-188, 109-116 (2001)), and a composite porous body can be synthesized by this method. However, MCM48 could not be obtained under the experimental conditions described in this document. Therefore, the synthesis conditions of MCM48 were optimized.

  In the above document, it is reported that MCM48 can be synthesized by the following procedure.

2.4 g (6.6 mmol) of CTAB is dissolved in 50 mL of deionized water and 50 mL (0.87 mol) of ethanol is added. Thereafter, 12 mL of aqueous ammonia (32 wt%, 0.2 mol NH ₃ ) is added, followed by stirring for 10 minutes, and 3.4 g (16 mmol) of TEOS is added. After stirring for 2 hours, the resulting solid is filtered and washed. After air drying, it is fired at 823 K for 6 hours (H ₂ O: EtOH: NH ₄ OH: CTAB: TEOS = 174: 54: 12.5: 0.4: 1).

(1) Effect of ethanol-water mixing ratio (Reference Examples 1 to 5)
A major difference between the synthesis method of MCM41 type mesoporous silica (hereinafter sometimes simply referred to as “MCM41”) and the synthesis method of MCM48 is that ethanol is added to the reaction solution in the latter synthesis method. Ethanol is coordinated to the hydrophilic group portion of the surfactant that forms micelles, and is said to be advantageous for MCM48 production by increasing the curvature.

  Thus, the function of ethanol plays an important role in the normal temperature synthesis method of MCM48. For this reason, as shown in Tables 1 and 2 below, MCM48 was synthesized by changing the mixing ratio of ethanol and water (room temperature).

  As a result of XRD measurement of the product obtained under each condition, a pattern of MCM48 appeared when ethanol was 0.18 with respect to water 1. However, the pattern did not completely match the pattern of MCM48 and included the pattern of MCM41. When there was less ethanol than this ratio, the pattern of MCM41 was produced, and when it was more, the main peak was wide and a pattern showing a structure with poor regularity in which the sub-peaks were not clear was generated.

  When ethanol enters the boundary between the hydrophilic group and the hydrophobic group of the surfactant, micelles of MCM48 are formed. Otherwise, there is no change in curvature, and micelles of MCM41 are considered to be formed.

(2) Influence of alcohol type (Reference Examples 6 to 11)
One of the factors that determine the shape of the micelle formed by the surfactant is curvature. Alcohol enters between the hydrophilic group and the hydrophobic group of the surfactant, and is considered to be advantageous for micelle formation of MCM48 by increasing the curvature.

  In order to see the effect of different hydrophobic alcohols on the product, methanol (Tables 3 and 4) with one less carbon than ethanol and propanol (Tables 5 and 6) with one carbon are included. The porous body was synthesized in the solution (room temperature).

  In the synthesis using methanol, an XRD pattern showing MCM41 appeared, and in propanol, an XRD pattern showing an irregular structure appeared. From this, it is considered that ethanol is most suitable as an alcohol added to the solvent.

  In the case of alcohol with low hydrophobicity such as methanol, alcohol molecules cannot enter between the hydrophobic part and hydrophilic part of the surfactant, and in the case of alcohol with high hydrophobicity such as propanol, alcohol molecules Would destroy the micelle structure.

(3) Effect of pH (Reference Examples 12 to 14)
The pH is involved in the rate of hydrolysis of TEOS. In normal synthesis, the pH was adjusted to about 11.8, but the synthesis was carried out with the pH lowered to about 11.0 (room temperature), and the effect on the product was confirmed (Tables 7 and 8).

  From the results of the XRD measurement, an XRD pattern showing an irregular structure appeared regardless of which alcohol, methanol, ethanol or propanol, was used.

  From this fact, it is considered that if the hydrolysis rate is too slow, it may be disadvantageous for the formation of a structure with good regularity because of the time allowance for the structure to collapse.

(4) Influence of ethanol-water mixing ratio (details) (Reference Examples 15 to 22)
From the results of Reference Examples 1 to 5, it was found that MCM48 was obtained when the ratio of ethanol to water was 0.18: 1. Furthermore, in order to confirm the influence of a detailed mixing ratio, the same synthesis was performed under the conditions of Tables 9 and 10 (room temperature).

  As a result of XRD measurement, a pattern of MCM48 was recognized when the mixing ratio of ethanol and water was in the range of 0.183 to 0.158: 1. However, the peak was broad, and the way the peak appeared was uneven. This unevenness is considered to be due to the effect of the synthesis temperature.

(5) Effect of synthesis temperature (Reference Examples 23 to 25)
Surfactants have a Kraft point and their micelle formation is thought to be affected by temperature. Therefore, synthesis was performed under the conditions shown in Tables 11 and 12 by changing the temperature in the forming process.

  As a result of XRD measurement of the porous body obtained at each temperature, an XRD pattern showing MCM48 could be confirmed under the condition of 15 ° C. A pattern showing a lamellar structure was confirmed at room temperature (25 ° C.), and a pattern showing an irregular structure was confirmed at 40 ° C.

  When the solution temperature becomes high, the surfactant is liberated from the micelles and reconstituted frequently, which is considered to be disadvantageous for the formation of regularly arranged micelles in combination with the stirring of the solution.

  The temperature of 15 ° C. is lower than the Kratab point (25 ° C.) of CTAB used as the surfactant in this experiment. Micelle should be formed above the Kraft point, but in this synthesis, a porous material was formed even at a temperature below the Kraft point. Since the surfactant and TEOS form micelles in concert, it is considered that the state is not determined by the nature of the surfactant alone. Moreover, when the solution temperature is lowered to less than 15 ° C., CTAB is precipitated. Therefore, when CTAB is used as the surfactant, the solution temperature is preferably within the range of 15 ° C. or more and 25 ° C. or less.

(6) Influence of CTAB concentration (Reference Examples 26 to 28)
CTAB forms micelles in concert with TEOS in a solution and becomes a template for porous silica. The shape of the micelles formed in the surfactant solution depends on the CTAB concentration and temperature. Further, when forming micelles in concert with other components (such as Si), the ratio is also important. Against this background, synthesis was carried out by changing the CTAB concentration (Tables 13 and 14), and the effect was examined.

  As a result of XRD measurement of the porous body obtained at each CTAB concentration, there was no significant difference in the XRD pattern of each porous body.

  There is also a report that a porous body is formed even if the concentration of the surfactant is lower than the cmc. Since the micelles are formed in concert, it is considered that the amount of the required surfactant is small, and therefore the change in the amount of the surfactant does not greatly affect the formation of the porous body.

(7) Effect of stirring time (Reference Examples 29 to 32)
When TEOS is added in the experimental operations shown in Reference Examples 1 to 5, the solution becomes cloudy after a few minutes, and the formation of silica can be confirmed. Silica in this state is not yet completely fixed in structure, and has a flexible structure that changes due to other treatments (hydrothermal treatment, firing, etc.). The possibility of the structure changing during stirring is also considered, so the effect on the product due to the difference in stirring time was confirmed.

  As a result of XRD measurement, no significant difference was observed in the XRD pattern of each porous body. It was confirmed that the porous body having a flexible structure can be changed in its structure by subsequent treatment, but the structure is not greatly changed by stirring at room temperature.

(8) Effect of mixing ratio of ethanol and water (15 ° C.) (Reference Examples 33 to 40)
Based on the results of Reference Examples 23 to 25, the influence of the mixing ratio of ethanol and water was examined again at 15 ° C.

  As a result of XRD measurement of the porous body obtained at each mixing ratio under the condition of 15 ° C., a pattern of MCM48 was observed when the mixing ratio of ethanol and water was in the range of 0.189 to 0.149: 1.

  In the future RT synthesis, it was decided to select an intermediate value of 0.17 out of the mixing ratios in which the production of MCM48 could be confirmed.

(9) Effects of mixing alcohol (Reference Examples 41 to 43)
An attempt was made to adjust the curvature to a value more suitable for MCM48 formation by adding methanol or propanol based on ethanol.

  As a result of XRD measurement of the product obtained at each mixing ratio, the product obtained by adding propanol has a higher ratio of lamellar structure than the product containing only ethanol. The product obtained by adding methanol has little formation of lamellar structure. It was found that the formation of lamellar structure can be suppressed by adding methanol, but this is not a big improvement, and since special attention (toxicity, etc.) is required for the use of methanol, only ethanol is used as alcohol. Is more preferable.

  From the results of Reference Examples 1 to 43 described above, the synthesis method was reviewed as follows.

2.4 g (6.6 mmol) of CTAB is dissolved in 60 mL of deionized water and 40 mL (0.70 mol) of ethanol is added. Thereafter, 15 mL of aqueous ammonia (28 wt%, 0.2 mol NH ₃ ) is added to bring the pH to about 11.8. The temperature of the solution is adjusted to 15 ° C. and 3.4 g (16 mmol) of TEOS is added all at once with stirring. After stirring for 2 hours, the resulting solid is filtered and washed. After air drying, the electric furnace is set to 813K over about 3 hours and fired for 6 hours (H ₂ O: EtOH: NH ₃ : CTAB: TEOS = 240: 42: 14: 0.4: 1, H ₂ O / EtOH = 5.3-6.7). The product obtained by this synthesis method is called “RT”, and the synthesis method is called “RT method”.

[Reference Examples 44 to 54] <Synthesis of MCM48-TiO ₂ Composite Porous Material by Hydrothermal Treatment>
There is a report that, after synthesizing MCM41, it can be changed into MCM48 by hydrothermal treatment using an autoclave (for example, Karl W. Gallis and Christopher C. Landry Chem. Mater. 9, 2035-2038). (1997)). Therefore, an attempt was made to synthesize an MCM48-TiO ₂ composite porous body by synthesizing an MCM41 composite porous body and then performing hydrothermal treatment to make the porous body portion MCM48. In the above report, it is reported that the phase of MCM 41 can be changed to MCM 48 by the following method.

CTAB is put into a 2 mol / L NaOH aqueous solution and heated to 35 to 40 ° C. to dissolve the surfactant. When TEOS is added, precipitation occurs after about 5 minutes. After returning to room temperature while stirring, hydrothermal treatment is performed at 150 ° C. using an autoclave. Stirring after the precipitation has occurred is suitably 2 hours, and hydrothermal treatment is suitably 4 hours (SiO ₂ : Na ₂ O: CTAB: H ₂ O = 8.4: 2.1: 1.0: 1108.9, H ₂ O: NaOH: CTAB: TEOS = 132: 0.5: 0.12: 1).

  No metastasis to MCM48 was observed with the above method. Therefore, the conditions were examined by changing the hydrothermal time (see Tables 21 and 22).

  As a result, an XRD pattern showing MCM-48 was confirmed when the hydrothermal time was 16 to 20 hours. Therefore, the synthesis method was reviewed as follows.

  0.73 g of CTAB is put into 40 mL of 0.2 mol / L NaOH aqueous solution and heated to 35 to 40 ° C. to dissolve the surfactant. TEOS is added with vigorous stirring and stirring is continued for about 2 hours after precipitation has occurred (MCM 41 at this point). The reaction solution is transferred to an autoclave and subjected to hydrothermal treatment at 150 ° C. for 16 to 20 hours. The product synthesized under these conditions is called “HT”, and the synthesis method is called “HT method”.

[Reference Examples 55 to 57] <Synthesis of MCM48 Using Gemini Type Surfactant>
A porous material was synthesized under the conditions shown in Tables 23 and 24 below using a gemini surfactant obtained by the following synthesis.

<Synthesis of Gemini type surfactant>
End dibromo alkane _(C m Br ₂₎ 5-10% excess of alkyl dimethyl amine equivalents (CsN _{(CH 3) 2)} and for 48 hours reflux in dehydrated ethanol. A gemini-type surfactant ( _{Cm -s-m} ) that is _{considered suitable} for _MCM48 is _C22-12-22 .

  A gemini surfactant was synthesized by the following method with reference to the synthesis method in the literature (R. Zana, M. Benrraou, and R. Rueff Languir. 7, 1072-1075 (1991)).

  Ethanol and molecular sieves were placed in an Erlenmeyer flask, covered, and then transferred to a dry box. In a dry box, 4.3 g (0.02 mol) of 1,6-dibromohexane and 10 g (0.041 mol) of N, N-dimethyl-n-dodecylamine are placed in a reaction vessel containing 50 mL of ethanol, and the reflux apparatus is set. Assembled. The apparatus was removed from the dry box and refluxed for 48 hours (oil bath temperature about 100 ° C.). After the reaction, ethanol was evaporated and cooled to obtain a gemini surfactant (GS).

As a result of the synthesis of the porous body, MCM41 was generated in any case in the synthesis with Gemini type surfactant / TEOS = 0.4, 1.2. Further, in the synthesis with a solution to which ethanol was added (EtOH / H ₂ O = 0.17), a porous body with poor regularity was generated.

  It is considered that the gemini surfactant synthesized this time was different from the compounds described in the literature in terms of the number of carbon atoms in both the bridging part and the hydrophobic part, and thus was not suitable for the production of MCM48.

[Example 1] <Synthesis of MCM48-TiO ₂ composite composite porous body>
The MCM48-TiO ₂ composite porous body was synthesized by the following method by the synthesis method after optimization (RT method).

2.4 g (6.6 mmol) of CTAB was dissolved in 60 mL of deionized water, and 40 mL (0.70 mol) of ethanol was added. Thereafter, 15 mL of aqueous ammonia (28 wt%, 0.2 mol NH ₃ ) was added, and 1.48 g of TiO ₂ (manufactured by Degussa, Germany, P-25) was added. Sonication was performed for 20 minutes to disperse TiO ₂ . After confirming that the pH was about 11.8, the temperature of the solution was adjusted to 15 ° C., and 3.4 g (16 mmol) of TEOS was added all at once with vigorous stirring. After stirring for 2 hours, the resulting solid was filtered and washed. After air drying, the electric furnace was brought to 813K over about 3 hours and baked for 6 hours (H ₂ O: EtOH: NH ₄ OH: CTAB: TEOS = 240: 42: 14: 0.4: 1, EtOH: H _{2 O = 0.175: 1, TiO 2} : (SiO 2 + TiO 2) = 0.6: 1). The composite porous material obtained by the above synthesis method is referred to as “RT-P25-60”.

Further, in the same manner, the ratio of TiO ₂ (weight basis) 30% ( "RT-P25-30"), was synthesized by 15% ( "RT-P25-15") was changed to the composite porous body .

  FIG. 1 shows the XRD measurement results of RT-P25-15, and Table 25 shows the nitrogen adsorption measurement results. As a result of XRD measurement, a pattern showing MCM48 was not observed both before and after firing. As for the nitrogen adsorption measurement result, it was confirmed that the RT-P25-15 composite porous body formed a slightly larger pore diameter than the MCM48 porous body. However, even in the RT-P25-15 composite porous body, a large surface area and pore volume are maintained, and composite formation is considered to have occurred without any problem.

The observation results of the SEM image and TEM image are shown in FIGS. 2 and 3, it was found that the TiO ₂ particles are encapsulated in a spherical porous body.

  4 and 5 show the XRD measurement results of RT-P25-30 and RT-P25-15, and Table 25 shows the nitrogen adsorption measurement results.

As shown in FIGS. 4 and 5, the pattern of MCM48 was confirmed in the composite porous body before firing in both RT-P25-15 and RT-P25-30, but the pattern disappeared after firing. It is unlikely that the structure that existed before firing is lost by firing. The reduction of the peak intensity due to the inclusion of TiO ₂ only makes it difficult to confirm the XRD pattern, and the structure of MCM 48 is considered to remain after firing.

Paying attention to the pore characteristics, the pore diameter of both RT-P25-15 and RT-P25-30 composite porous bodies was close to the diameter of the MCM48 porous body, and was about 1.9 nm. This strongly suggests the production of MCM48. Also, the only difference in the synthesis of RT-P25-60, RT-P25-15, and RT-P25-30 is the proportion of TiO ₂ , and other conditions are the same. It is considered that the MCM 48 is generated.

<Synthesis of MCM48-TiO ₂ composite porous body according to hydrothermal treatment> Example 2
Based on the results of Reference Examples 44 to 54, composite porous bodies were synthesized as follows.

0.73 g of CTAB was put into 40 mL of 0.2 mol / L NaOH aqueous solution and heated to 35 to 40 ° C. to dissolve the surfactant. 1.5 g of TiO ₂ (manufactured by Degussa, Germany, P-25) was added and sonication was performed for 20 minutes. While vigorously stirring, 3.4 g (16 mmol) of TEOS was added, and stirring was continued for about 2 hours after precipitation occurred (at this time, the MCM41 composite porous body). The reaction solution was transferred to an autoclave and hydrothermally treated at 150 ° C. for 18 hours. The composite porous body obtained by the above method is referred to as “HT-P25-60”.

Further, in the same manner, the ratio of TiO ₂ (weight) of 30% ( "HT-P25-30"), was synthesized by 15% ( "HT-P25-15") was changed to the composite porous body.

  The XRD measurement results are shown in FIG. 6, and the nitrogen adsorption measurement results are shown in Table 25. FIG. 6 is a graph showing XRD measurement results of (a) before firing, (b) after hydrothermal treatment 18h, and (c) after firing of HT-P25-60.

  As shown in FIG. 6, a clear XRD pattern was not observed before and after firing, and the production of MCM48 could not be confirmed. As for the pore characteristics, the pore diameter was 2.7 nm, which was larger than the diameter 2.1 nm of the MCM48 porous material obtained by hydrothermal synthesis, and was the same value as MCM41. As described above, an analysis result indicating the generation of MCM48 was not obtained for the composite porous body of this example.

The SEM image and TEM image of the composite porous body are shown in FIGS. From the SEM image, it was observed that a part of TiO ₂ particles (diameter of about 25 nm) leaked out of the composite porous body. In the TEM image, it was confirmed that the TiO ₂ particles were encased in the porous body. Although there are particles that have partially come out of the porous body, it was confirmed that most of TiO ₂ was encased in the porous body.

<Synthesis of MCM48-TiO ₂ composite porous body according to two-step synthesis> Example 3
By the HT method, in the case of only the porous body, complete MCM48 could be generated. However, as shown in Example 2, no clear XRD pattern indicating the formation of MCM48 was observed in the composite porous body. The difference in the synthesis between the _two is the presence or absence of the addition of TiO ₂ , and the TiO ₂ particles may inhibit the production of MCM48. In RT synthesis, a composite porous body is formed so that the porous body wraps around the TiO _{2 in} a spherical shape. Therefore, an attempt was made to synthesize the MCM48 composite porous material by covering the TiO ₂ particles with the porous material by the RT method in the first step and using the HT method in the second step.

<First stage>
2.4 g (6.6 mmol) of CTAB was dissolved in 60 mL of deionized water, and 40 mL (0.70 mol) of ethanol was added. Thereafter, 15 mL of aqueous ammonia (28 wt%, 0.2 mol NH ₃ ) was added, and 1.48 g of TiO ₂ (manufactured by Degussa, Germany, P-25) was added. Sonication was performed for 20 minutes to disperse TiO ₂ . After confirming that the pH was about 11.8, the temperature of the solution was adjusted to 15 ° C., and TEOS Xg was added all at once with vigorous stirring. After stirring for 2 hours, the resulting solid was filtered and washed. After air drying, the electric furnace was set to 813K over about 3 hours and baked for 6 hours.

<Second stage>
0.73 g of CTAB was put into 40 mL of 0.2 mol / L NaOH aqueous solution and heated to 35 to 40 ° C. to dissolve the surfactant. The coated TiO ₂ was added with the porous material synthesized in the first stage and sonicated for 20 minutes. TEOS Yg was added with vigorous stirring, and stirring was continued for about 2 hours after precipitation occurred (at this time, the MCM41 composite porous body). The reaction solution was transferred to an autoclave and hydrothermally treated at 150 ° C. for 16 hours. _{Incidentally,} X + Y = _3.5g, synthetic such that the _{TiO 2 / (TiO 2 + SiO} 2) = 0.6 was conducted.

The composite porous body obtained by the above method is called “RTxHTy-P25-60” (for example, in the case of TiO ₂ 60% composite porous body using TEOS 1.0 g in the first stage and TEOS 2.5 g in the second stage) RT _1.0 HT _2.5 -P25-60.

The XRD measurement results are shown in FIGS. 9 to 11, and the nitrogen adsorption measurement results of RT _1.5 HT _2.0 -P25-60 are shown in Table 25. FIG. 9 is a graph showing the XRD measurement results of RT _0.5 HT _3.0 -P25-60 after (a) coating by RT method, (b) after HT method hydrothermal treatment 16h, and (c) after firing. There, FIG. 10 _shows after coating by RT _1.0 HT 2.5 -P25-60 of (a) RT method, after (b) HT method hydrothermal treatment 16h, the XRD measurement results in, after calcination (c) a graph, FIG. _11, RT _1.5 HT 2.0 after coating with -P25-60 of (a) RT method, (b) after HT method hydrothermal treatment 16h, XRD measurement results in, after calcination (c) It is a graph which shows.

  As shown in FIGS. 9 to 11, in all cases, only a wide peak was observed in the vicinity of 2.5 °, and a peculiar pattern indicating generation of MCM41 or MCM48 was not obtained. As a result of nitrogen adsorption measurement, the pore diameter was 2.7 nm, which was the same as the value of MCM41, as in the case of the product in normal HT synthesis.

In order to examine whether or not MCM48 was generated in the 60% composite porous body, composite porous bodies having a TiO ₂ content of 15% and 30% were synthesized and compared. The XRD measurement results are shown in FIG. FIG. 12 is a graph showing XRD measurement results of RT _0.5 HT-P25-X at (a) X = 15%, (b) X = 30%, and (c) X = 60%.

As shown in FIG. 12, a peak pattern of MCM48 was observed for 15% of the composite porous body. In the case of containing more TiO ₂ , the pattern indicating the generation was not observed, but it is considered that the generation of MCM48 occurs because the composite porous body was subjected to the same treatment.

Example 4 Synthesis of Composite Porous Material Using TiO ₂ Modified with Organic Compound
It has been found that when TiO ₂ modified with an organic compound is used, TiO ₂ particles (manufactured by Degussa, Germany, P-25) are well included in the porous body, and a more highly active composite porous body is obtained. In response, a composite porous body was synthesized using TiO ₂ modified with an organic compound.

<Synthesis of TiO ₂ modified with organic compound>
TiO ₂ (manufactured by Degussa, Germany, P-25) was dried in vacuum at 200 ° C. for 2 hours to remove moisture. In a dry box, 3 g of TiO ₂ and 15 g of a silane coupling agent were placed in 60 mL of dehydrated toluene. The reaction vessel was filled with Ar gas, taken out from the dry box, and refluxed for 24 hours to organically modify TiO ₂ . Note that n-octadecyltriethoxysilane (CH ₃ (CH ₂ ) ₁₇ Si (OC ₂ H ₅ ) ₃ ) was used as a silane coupling agent.

After completion of the reaction, washing was performed with toluene in a dry box. A sample was taken out, washed with methanol, and vacuum-dried at about 50 ° C. for 5 hours to synthesize TiO ₂ modified with an organic compound.

<Synthesis of Composite Porous Material Using TiO ₂ Modified with Organic Compound>
Instead of using TiO ₂ particles (manufactured by Degussa, Inc., P-25), the same operation as in Example 1 was performed except that the above-described organically modified TiO ₂ was used, and a composite porous body (RT-C18P25- 60) was synthesized.

  The XRD measurement results are shown in FIG. 13 and the nitrogen adsorption measurement results are shown in Table 25. As for the XRD measurement, a clear pattern was not seen as in the case of the conventional composite porous body. However, as a result of nitrogen adsorption measurement, it was found that the pore diameter was close to the diameter of the MCM48 porous body. From this, it is considered that the composite porous body using C-18P25 contains MCM48 at a higher ratio.

Example 5
Instead of using TiO ₂ particles (manufactured by Degussa, Germany, P-25), the same operation as in Example 2 was performed except that TiO ₂ subjected to organic modification in Example 4 was used, and a composite porous body (HT -C18P25-60) was synthesized.

The XRD measurement results are shown in FIG. 14 and the nitrogen adsorption measurement results are shown in Table 25. The XRD pattern is broken in such a way that the strength decreases from a low angle. Moreover, almost no capillary condensation is observed in the nitrogen adsorption measurement result, and the outer surface area is large. From these facts, it is considered that the structure of the composite porous body is considerably broken in the synthesis of the composite porous body by the HT method using TiO ₂ subjected to organic modification.

[Comparative Example 1] <Synthesis of MCM41-P25-60>
Surfactant hexadecyltrimethylammonium bromide 0.86 g was dissolved in 46 g of ion-exchanged water while heating. Aqueous ammonia was added to adjust the pH to 11.8. To the solution, 1.46 g of TiO ₂ particles (manufactured by Degussa, Germany, P-25) was added, and ultrasonic waves were well dispersed over 20 minutes. Next, with vigorous stirring, 3.38 g of tetraethoxysilane was added all at once and stirred for 1 hour. The product was filtered, washed with ion-exchanged water, dried overnight at 80, and finally baked at 540 ° C. for 6 hours to remove the surfactant, thereby synthesizing MCM41-P25-60.

<About decomposition experiment results>
Table 26 shows the result of each decomposition experiment performed on each composite porous body synthesized in the above Examples and Comparative Examples. Moreover, the graph which shows a time-dependent change of each phenol type decomposition | disassembly experiment of RT-P25-60, HT-P25-60, and MCM41-P25-60 is shown to FIGS. 15 to 17, the broken line parallel to the Y axis represents the decomposition start time.

* 1) Activity ratio = (NP decomposition rate) / (NP decomposition rate of titanium oxide (P-25))
* 2) Speed ratio = (decomposition rate) / (NP decomposition rate)
In the phenol-based degradation experiment of RT-P25-60, the decomposition rate of nonylphenol was higher than that of MCM41-P25-60. Further, decomposition selectivity between n-heptylphenol and nonylphenol, which was not found in MCM41-P25-60, occurred.

  In the phenol-based degradation experiment of HT-P25-60, the degradation rate was generally lower than that of MCM41-P25-60. However, the degradation selectivity of n-heptylphenol and nonylphenol occurred as seen in RT-P25-60. In the aniline-based decomposition experiment, the overall decomposition rate was low.

As a result of performing each decomposition experiment using RT _1.5 HT _2.0 -P25-60, both phenol-based and aniline-based decomposition experiments were almost the same as HT-P25-60. The common point between HT-P25-60 and RT _1.5 HT _2.0- P25-60 is that hydrothermal treatment is performed, and during the hydrothermal treatment, silica is precipitated or corroded on the surface of the composite porous body. It is thought to occur and become less active.

In the phenol-based decomposition experiment of RT-C18P25-60, the activity was slightly inferior to that of RT-P25-60, but the decomposition of phenol and n-propylphenol was reduced, and the selectivity was improved. This improvement in selectivity is considered to be due to the TiO ₂ particles being completely included in the porous body by organic modification.

In the phenolic degradation experiment of HT-C18P25-60, the activity was lower than that of HT-P25-60. One of the reasons why the activity of HT-P25-60 is low is considered to be silica deposition on the surface of TiO ₂ particles. By performing organic modification, it becomes easier for the surfactants to be arranged in a layered manner on the particle surface, and it is considered that silica is precipitated as it is in a situation without stirring such as hydrothermal treatment.

  Rhodamine B, which is an organic compound having a large molecular structure, and methylene blue are selected as models, and decomposition experiments of the mixed solution are performed as P-25, MCM41-P25-60, RT-P25-60, RT-C18P25-60, RT- According to the results of C18P25-60, P-25 has approximately the same degradation rate of rhodamine B and methylene blue, and has no selectivity, whereas the composite porous body decomposes methylene blue faster than rhodamine B. It was found that selectivity occurs. Overall, rhodamine B is more adsorbed on the composite porous body, but the decomposition rate is higher with methylene blue.

Moreover, about MCM41-P25-60 and RT-P25-60, the decomposition | disassembly rate was quicker than P-25. For composite porous material was synthesized using TiO ₂ subjected to organic modification the activity was lower than the composite porous body of the corresponding non-organic-modified TiO _2.

In organically modified TiO ₂ , it is considered that the ethanol used in this synthesis is coordinated on the surface. Ethanol has the effect of increasing the curvature of the surfactant, and micelles change phase to hexagonal, cubic, and lamella with increasing curvature. Therefore Doing composite porous body synthesis using organic modified TiO ₂ in a solvent comprising ethanol, silica film resulting from lamellar phase is formed on the surface, believed to reduce the activity.

  FIG. 18 is a graph showing the relationship between the amount adsorbed on the composite porous body and the decomposition rate. In addition, each plot shows phenol, propylphenol, heptylphenol, and nonylphenol in order from the compound having the lowest adsorption amount to the composite porous body.

  As shown in FIG. 18, in RT-P25-60, the adsorption amount to the composite porous body and the decomposition rate show a positive correlation, and the selectivity of decomposition is attributed to the selectivity of molecular adsorption. it is conceivable that. In addition, it was confirmed that RT-P25-60 decomposed efficiently with a higher decomposition rate with respect to the amount of adsorption to the composite porous body than MCM-41-P25-60.

  The composite porous body of the present invention has high molecular selectivity. Therefore, harmful organic substances can be selectively decomposed, and extremely low concentrations of harmful substances can be selectively removed from water or air. This technology can be used for purification and removal of harmful substances in all fields. It is particularly suitable for water purification and sewage treatment.

It is a graph which shows the XRD measurement result of RT-P25-60. It is drawing which shows the SEM image of RT-P25-60. It is drawing which shows the TEM image of RT-P25-60. It is a graph which shows the XRD measurement result of RT-P25-15. It is a graph which shows the XRD measurement result of RT-P25-30. It is a graph which shows the XRD measurement result in (a) before baking of HT-P25-60, (b) after hydrothermal treatment 18h, and (c) after baking. It is drawing which shows the SEM image of HT-P25-60. It is drawing which shows the TEM image of HT-P25-60. After coating with the RT _0.5 HT _3.0 -P25-60 of (a) RT method, (b) after HT method hydrothermal treatment 16h, is a graph showing an XRD measurement results in, after calcination (c). After coating with the RT _1.0 HT _2.5 -P25-60 of (a) RT method, (b) after HT method hydrothermal treatment 16h, is a graph showing an XRD measurement results in, after calcination (c). After coating with the RT _1.5 HT _2.0 -P25-60 of (a) RT method, (b) after HT method hydrothermal treatment 16h, is a graph showing an XRD measurement results in, after calcination (c). (A) X = 15, is a graph illustrating the (b) X = 30, ( c) X = 60 XRD measurement results of _RT 0.5 HT-P25-X in. It is a graph which shows the XRD measurement result of RT-C18P25-60. It is a graph which shows the XRD measurement result of HT-C18P25-60. It is a graph which shows a time-dependent change of the phenol-type decomposition | disassembly experiment of RT-P25-60. It is a graph which shows a time-dependent change of the phenol-type decomposition | disassembly experiment of HT-P25-60. It is a graph which shows a time-dependent change of the phenol-type decomposition | disassembly experiment of MCM41-P25-60. It is a graph which shows the relationship between the adsorption amount to a composite porous body, and a decomposition rate.

Claims (13)

In a method for producing a composite porous body that forms a composite porous body in an aqueous surfactant solution,
A step of mixing and dispersing solid fine particles in an aqueous surfactant solution before the porous skeleton is formed;
A step of mixing ethanol in an aqueous surfactant solution before the porous skeleton is formed;
Forming a composite porous body in which the porous body and the solid fine particles are combined by generating a skeleton of the porous body in the aqueous solution in which the solid fine particles are dispersed ,
The step of forming the composite porous body is carried out at a temperature below the Kraft point of the surfactant and at a temperature not lower than the temperature at which no dissolved matter precipitates in the aqueous surfactant solution . Production method. The method for producing a composite porous body according to claim 1, wherein the solid fine particles are fine particles made of a metal sulfide or metal oxide having a photocatalytic function .   The method for producing a composite porous body according to claim 1 or 2, wherein the solid fine particles are titanium dioxide.   The composite porosity according to any one of claims 1 to 3, wherein the ethanol is mixed in the aqueous solution within a range of 0.05 to 0.5 with respect to water 1 by volume ratio. Body manufacturing method.   The method for producing a composite porous body according to any one of claims 1 to 4, wherein the surfactant is a cationic surfactant.   The method for producing a composite porous body according to claim 5, wherein the cationic surfactant is CTAB (cetyltrimethylammonium bromide).   The composite porous body according to any one of claims 1 to 6, wherein the porous body is at least one porous body selected from porous silica, zeolite, porous alumina, and porous silica alumina. Manufacturing method.   The method for producing a composite porous body according to claim 7, wherein the porous body is mesoporous silica.   The method for producing a composite porous body according to claim 8, wherein the porous body is MCM-48 type mesoporous silica.   The method for producing a composite porous body according to any one of claims 1 to 9, wherein the solid fine particles are modified with an organic compound. It is manufactured by the method for manufacturing a composite porous body according to any one of claims 1 to 10 ,
A composite porous body comprising a composite porous body in which a porous material and solid fine particles are combined .   The composite porous body according to claim 11, wherein the solid fine particles are fine particles made of a metal sulfide or metal oxide having a photocatalytic function. The composite porous body according to claim 11 or 12, wherein the solid fine particles are titanium dioxide.