KR101912805B1 - Self-assembled 3D hybrid structure, method for preparing the same, and photocatalysts using the same - Google Patents

Abstract

The present invention relates to a self-assembled three-dimensional hybrid structure, a method of manufacturing the same, and a photocatalyst using the same, wherein self-assembly is performed by reacting a metal oxide with a separated metal double layer hydroxide (LDH) nanosheet having a surface charge, Organic structure (MOF) is inserted between the hydroxide (LDH) nanosheets so that the micropores are formed at 0.1 to 1.0 cm ³ / g and the mesopores are formed simultaneously at 0.1 to 1.0 cm ³ / g, Excellent stability can be secured even though a low-stability metal-organic structure (MOF) is used.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-assembled three-dimensional hybrid structure, a method of manufacturing the same, and a photocatalyst using the self-

The present invention relates to a three-dimensional hybrid structure produced by self-assembling a metal-organic structure (MOF) on the surface of a peeled metal double layer hydroxide (LDH) nanosheet, a method for producing the same, and a photocatalyst using the same.

Photocatalysis refers to a substance that catalyzes a chemical reaction by a variety of light sources, including sunlight. Photosynthesis occurring in the chlorophyll of a plant is a representative photocatalysis system.

Photocatalyst system is decomposed with water to decompose water to produce oxygen and hydrogen (water splitting), CO ₂ reduction that produce methanol and methane by using CO ₂ (CO ₂ reduction), photolysis for decomposing the harmful organic matters to the body ( photo degradation.

This photocatalytic system is a system that exerts its own action by using only sunlight without obtaining energy from the outside. Since the photocatalyst used here is harmless to the human body and can be reused under specific conditions, it can be considered as a next generation clean energy source.

In particular, water decomposition produces hydrogen gas by decomposing water by the following equation.

H ₂ O → 1 / 2O ₂ + H ₂ (ΔG = 237 KJ / mol)

Water decomposition requires a photocatalyst that absorbs sunlight, causing electrons to exude from the valence band to the conduction band. The photocatalyst should be hydrophilic because it is inexpensive, harmless to the human body, excellent in stability, and often reacts directly with water.

The standard Gibbs free energy change of the water decomposition reaction is 237 kJ / mol, the band gap energy is 1.23 eV, and TiO ₂ is mainly used as a photocatalyst since it satisfies these conditions . However, the band gap energy of the TiO ₂ is 3.0 eV, which is not suitable for using visible light.

When the electrons are excited, the recombination occurs in which the excited electrons are recombined with the holes. If this phenomenon occurs, the efficiency of hydrogen generation is decreased. Therefore, in order to prevent this, a method of coating a cocatalyst acting as an election trap on the surface of the catalyst is used. However, when this method is used, the manufacturing cost is increased and there is a problem of producing the catalyst.

On the other hand, sunlight has light in the range of ultraviolet rays (300 to 400 nm), visible light (400 to 700 nm) and near infrared rays (700 to 2500 nm), and visible light occupies about 43% do.

In the case of TiO ₂ , which is mainly used as a photocatalyst, only 5% of the sunlight irradiated on the ground surface is used because it absorbs light of 400 nm or less. In order to solve the above problems, a dye-sensitized photocatalysis using visible light dyes has been developed. However, dye-sensitized photocatalysis using expensive ruthenium is expensive and environmentally unstable. have.

Therefore, the photocatalyst is excellent in the effect as a photocatalyst for use as a photocatalyst, and is not only easy to manufacture but also requires a stable substance.

Korean Patent No. 1623736

Nanoscale, v.5 no.23, 2013, pp.11770-11775  Chem comm v.50 no.32, pp.4225-4227, 2014  Advanced materials, v.28 no.12, 2016, pp.2337

It is an object of the present invention to provide a three-dimensional hybrid structure produced by self-assembling a metal-organic structure (MOF) on the surface of a separated metal double layer hydroxide (LDH) nanosheet.

Another object of the present invention is to provide a method for manufacturing the three-dimensional hybrid structure.

It is still another object of the present invention to provide a photocatalyst using the three-dimensional hybrid structure.

In order to accomplish the above object, the present invention provides a three-dimensional hybrid structure comprising a metal double-layer hydroxide (LDH) nanosheet on which a ligand is located, The metal-organic structure (MOF) is formed by assembly,

 Two or more separated metal double-layer hydroxide (LDH) nanosheet surfaces may be connected by a metal-organic structure (MOF) to form a three-dimensional structure.

The three-dimensional hybrid structure may have a micropores of 0.01 to 1.0 cm ³ / g and a mesopore of 0.01 to 1.0 cm ³ / g.

The three-dimensional hybrid structure may have micropores and mesopores in a volume ratio of 1: 0.01-1.

The exfoliated metal double layer hydroxide (LDH) nanosheet may be a compound represented by the following Chemical Formula 1:

[Chemical Formula 1]

[M ^II _(1-x) M ^III _x (OH) ₂ ] [A ^n- ] _{x / n} .zH ₂ O;

In the general formula 1, wherein M ^II is a ^{Ca 2 +, Mg 2 +,} Zn 2 +, Ni 2 +, Mn 2 +, Co 2 +, Fe 2 +, Cu 2 + , and from the group consisting of mixed metal Selected,

Wherein M ^III is selected from ^{3 +} Fe, Al ^{+ 3,} Cr ^{+ 3,} Mn ^{+ 3,} Ga ^{+ 3,} Co ^{+ 3,} Ni ^{+ 3,} and the group consisting of mixed metal,

Wherein A ^n- is selected from the group consisting of hydroxide ions (OH ^- ), nitrate ions (NO ^{3 -} ), PO ₄ ^{3 -} , HPO ₄ ^{2 -} , H ₂ PO ^{4 -}

0 < x < 1, and z is a real number of 0.1 to 15.

The metal-organic structure (MOF) may be a compound represented by the following Chemical Formula 2:

(2)

[M _x (L) _y (S) _z ] S;

Wherein M is ^{Li +, Mg 2 +, Al} 3 +, Ti 2 +, Ti 3 +, Ti 4 +, V 3 +, V 4 +, V 5 +, Cr 2 +, Cr 3 +, Mn 2 +, ^{Mn 3 +, Mn 4 +,} Mn 6 +, Mn 7 +, Fe 2+, Fe 3 +, Co 2 +, Co 3 +, Ni 2 +, Cu +, Cu 2 +, Zn 2 +, Ag + , and And mixtures of these metals,

The L (ligand) may be selected from the group consisting of 2-aminoterephthalic acid (NH ₂ -H ₂ BDC), terephthalic acid (H ₂ BDC), 2,5-dihydroxyterephthalic acid dihydroxyterephthalic acid, H ₂ DOBDC), trimesic acid (H ₃ BTC), imidazole (IM) and 1-methyl imidazole (CH ₃ -IM) It can be more than a species.

The S (solvent) may be selected from the group consisting of N, N-Dimethyl Formamide (DMF), Formaldehyde (FA), N, N-Diethyl Formamide (DEF), Dimethylacetamide ), Methanol (MeOH), ethanol (EtOH), tetrahydrofuran (THF), water (H ₂ O), 1-methyl- N-dimethylformamide (NMP), dimethyl sulfoxide (DMSO), diethyl ether (Ether), and mixed solvents thereof.

1 <x <3, 1 <y <3, and 1 <z <3

According to another aspect of the present invention, there is provided a method for fabricating a three-dimensional hybrid structure, comprising the steps of: (A) adding an exfoliated metal double layer hydroxide (LDH) nanosheet and a ligand to an organic solvent to form an ultrasonic wave sonication); And

(B) performing a self-assembly by adding metal ions to the ultrasound-treated solution and reacting the metal ions to form a metal-organic structure (MOF), wherein two or more separated metal double layer hydroxide (LDH) A three-dimensional hybrid structure formed by a three-dimensional structure can be provided.

Dimensional hybrid structure in which a metal-organic structure (MOF) is inserted between the metal double layer hydroxide (LDH) nanosheets.

The metal double layer hydroxide (LDH) nanosheet and the ligand which are separated in the step (A) may be mixed in a weight ratio of 1: 5 to 200.

In the step (A), the ligand is selected from the group consisting of 2-aminoterephthalic acid (NH ₂ -H ₂ BDC), terephthalic acid (H ₂ BDC), 2,5-dihydroxyterephthalic acid 5-dihydroxyterephthalic acid, H ₂ DOBDC), trimesic acid (H ₃ BTC), imidazole (IM) and 1-methyl imidazole (CH ₃ -IM) It may be at least one selected.

In step (A), the organic solvent may be selected from the group consisting of N, N-Dimethyl Formamide (DMF), formaldehyde (FA), N, N-Diethyl Formamide (DEF), dimethylacetamide Dimethylacetamide, DMA), methanol, MeOH, ethanol, EtOH, Tetrahydrofuran, THF, water, H ₂ O, 1-methyl -2-pyrrolidinone, NMP, dimethylsulfoxide (DMSO), diethyl ether (Ether), and mixed solvents thereof.

The separated metal double layer hydroxide (LDH) nanosheet used in the step (A) and the metal ion used in the step (B) may be mixed in a weight ratio of 1: 5 to 200.

The metal ion used in the step (B) is ^{Li +, Mg 2 +, Al} 3 +, Ti 2 +, Ti 3 +, Ti 4 +, V 3 +, V 4 +, V 5 +, Cr 2 +, ^{Cr 3 +, Mn 2+, Mn} 3 +, Mn 4 +, Mn 6 +, Mn 7 +, Fe 2 +, Fe 3 +, Co 2 +, Co 3 +, Ni 2 +, Cu +, Cu 2+ , Zn ^{2 +} , Ag ^+, and mixed metal ions thereof.

In the step (B), the self-assembly may be performed at 50 to 200 ° C for 10 to 24 hours.

According to another aspect of the present invention, there is provided a photocatalyst comprising the three-dimensional hybrid structure.

The photocatalyst may be a photocatalyst that decomposes water to generate hydrogen.

The three-dimensional hybrid structure of the present invention is formed by self-assembling a metal-organic structure (MOF) on the surface of a separated metal double layer hydroxide (LDH) nanosheet, and is hybridized to a mesopore (diameter: 2.0-50.0 nm) Since these small micro pores (diameter: 0.1-1.9 nm) are generated so much, nitrogen adsorption / desorption is excellent.

In addition, the three-dimensional hybrid structure of the present invention can secure excellent stability even though a metal-organic structure (MOF) having a relatively low optical and chemical stability is used.

As described above, the three-dimensional hybrid structure, which is stable and has a plurality of micropores, can also be used as a photocatalyst.

1 is a flowchart illustrating a process of fabricating a three-dimensional hybrid structure according to an embodiment of the present invention.
2 is a flow chart illustrating a process for producing a metal double layer hydroxide (LDH) nanosheet from a metal double layer hydroxide (LDH).
FIG. 3A is a SEM photograph of the surface of a Ti-MOF @ ZnCr-LDH three-dimensional hybrid structure manufactured according to Example 1 of the present invention, and FIG. 3B is a cross- @ ZnCr-LDH The three-dimensional hybrid structure was photographed by SEM.
4 is a graph showing N ₂ adsorption-desorption isotherms of a Ti-MOF @ ZnCr-LDH three-dimensional hybrid structure produced according to Examples 1 and 2 of the present invention.
FIG. 5 is a graph showing the size distribution of micro pores formed on the Ti-MOF @ ZnCr-LDH three-dimensional hybrid structure produced according to Examples 1 and 2 of the present invention.
6A is a diffuse reflection UV-vis absorption spectrum graph of the Ti-MOF prepared according to Production Example 3 of the present invention and the Ti-MOF @ ZnCr-LDH three-dimensional hybrid structure produced according to Example 1 and Example 2, FIG. 6B is an enlarged graph of the absorption spectrum of FIG. 6A. FIG.

The present invention relates to a three-dimensional hybrid structure produced by self-assembling a metal-organic structure (MOF) on the surface of a peeled metal double layer hydroxide (LDH) nanosheet, a method for producing the same, and a photocatalyst using the same.

The present invention solves the problem of partial crystallization of a two-dimensional structure (LDH nanosheet) often generated by reaction on an immobilized surface and low dispersion of a two-dimensional structure in solution. In addition, the problem of the peeled metal double layer hydroxide (LDH) nanosheets exhibiting low specific surface area and structural instability is solved by manufacturing a three-dimensional hybrid structure.

Hereinafter, the present invention will be described in detail.

The three-dimensional hybrid structure of the present invention can be produced by reacting a metal ion with a separated metal double-layer hydroxide (LDH) nanosheet on which a ligand is present on the surface, and by self-assembling to the surface of the separated metal double layer hydroxide (LDH) (MOF) to form the metal-organic structure (MOF) to connect the surface of two or more metal double layer hydroxide (LDH) nanosheets.

Specifically, a conventional metal double layer hydroxide (LDH) is peeled off as a single nano layer to broaden the specific surface area, and the self-assembly of the metal ion and the ligand on the surface of the separated metal double layer hydroxide (LDH) (LDH) nanosheets and a metal-organic structure (MOF) are hybridized to form a hybrid structure.

Conventionally, there has been a technique of self-assembling a metal or an organic ligand on a metal or carbon surface to grow a two-dimensional metal-organic structure (MOF). However, since this leads to epitaxial growth on the immobilized surface, It was impossible to obtain a three-dimensional hybrid structure in which the two-dimensional structure was hybridized with the monolayer.

However, the present invention relates to a method for preparing a metal-organic structure (MOF) by controlling the crystal growth on the surface of a metal double layer hydroxide (LDH) nanosheet such that two or more separated metal double layer hydroxide (LDH) nanosheets, Two or more separated metal double-layer hydroxide (LDH) nanosheets as a two-dimensional structure are induced to self-assemble, so that a three-dimensional hybrid structure can be obtained because the two or more nanosheets are hybridized to a monolayer.

When a conventional metal double layer hydroxide (LDH) is used instead of the exfoliated metal double layer hydroxide (LDH) nanosheet, the specific surface area is low and the efficiency of the photocatalyst is not high and the metal-organic structure (MOF) The structure can not be manufactured.

The metal double layer hydroxide (LDH) nanosheet may include, but is not limited to, a metal double layer hydroxide (LDH) nanosheet represented by the following formula (1).

[Chemical Formula 1]

[M ^II _(1-x) M ^III _x (OH) ₂ ] [A ^n- ] _{x / n} .zH ₂ O;

In the general formula 1, wherein M ^II is a ^{Ca 2 +, Mg 2 +,} Zn 2 +, Ni 2 +, Mn 2 +, Co 2 +, Fe 2 +, Cu 2 + and in the group consisting of a mixture of these metals Selected,

Wherein M ^III is selected from ^{3 +} Fe, Al ^{+ 3,} Cr ^{+ 3,} Mn ^{+ 3,} Ga ^{+ 3,} Co ^{+ 3,} Ni ^{+ 3,} and the group consisting of mixed metal,

Wherein A ^n- is selected from the group consisting of hydroxide ions (OH ^- ), nitrate ions (NO ^{3 -} ), PO ₄ ^{3 -} , HPO ₄ ^{2 -} , H ₂ PO ^{4 -}

0 &lt; x &lt; 1, and z is a real number of 0.1 to 15.

The metal double layer hydroxide (LDH) nanosheet represented by Chemical Formula 1 is subjected to a coprecipitation step and then the metal double layer hydroxide salt is reacted with 1-butanol, 1-hexanol, 1-octanol 1-octanol, 1-decanol, CCl ₄ , xylene, and formamide to form a metal double layer having a cation surface charge, (Release) in the form of a hydroxide salt in the form of nanosheets. The type of the solvent is not limited as long as it can dissolve the metal double layer hydroxide salt.

Further, the ligand is not particularly limited as long as it is a material that connects the metal double layer hydroxide (LDH) nanosheets, but preferably 2-aminoterephthalic acid (NH ₂ -H ₂ BDC), terephthalic acid terephthalic acid, H ₂ BDC), 2,5-dihydroxyterephthalic acid (H ₂ DOBDC), trimesic acid (H ₃ BTC), imidazole, IM) and 1 Methyl imidazole (CH ₃ -IM), and the like.

In addition, the metal ion is ⁺ Li, Mg ^{+ 2,} Al ^{+ 3,} Ti ^{+ 2,} Ti ^{+ 3,} Ti ^{+ 4,} V ^{+ 3,} V ^{+ 4,} V ^{+ 5,} Cr ^{2 +,} Cr ^3+, Mn ^{2 +, Mn 3 +, Mn} 4 +, Mn 6+, Mn 7 +, Fe 2 +, Fe 3 +, Co 2 +, Co 3 +, Ni 2 +, Cu +, Cu 2 +, Zn 2 +, Ag ⁺ and mixed metal ions thereof.

The metal-organic structure (MOF) self-assembled using the ligand and the metal ion may be a compound represented by the following formula (2).

(2)

[M _x (L) _y (S) _z ] S;

The M (metal ions) is ^{Li +, Mg 2 +, Al} 3 +, Ti 2 +, Ti 3 +, Ti 4 +, V 3 +, V 4 +, V 5 +, Cr 2 +, Cr 3 +, ^{Mn 2 +, Mn 3 +,} Mn 4 +, Mn 6+, Mn 7 +, Fe 2 +, Fe 3 +, Co 2 +, Co 3 +, Ni 2 +, Cu +, Cu 2 +, Zn 2 + , Ag ^+, and mixed metal ions thereof,

The L (ligand) may be selected from the group consisting of 2-aminoterephthalic acid (NH ₂ -H ₂ BDC), terephthalic acid (H ₂ BDC), 2,5-dihydroxyterephthalic acid dihydroxyterephthalic acid, H ₂ DOBDC), trimesic acid (H ₃ BTC), imidazole (IM) and 1-methyl imidazole (CH ₃ -IM) It can be more than a species.

The S (solvent) may be selected from the group consisting of N, N-Dimethyl Formamide (DMF), Formaldehyde (FA), N, N-Diethyl Formamide (DEF), Dimethylacetamide ), Methanol (MeOH), ethanol (EtOH), tetrahydrofuran (THF), water (H ₂ O), 1-methyl- N-dimethylformamide (NMP), dimethyl sulfoxide (DMSO), diethyl ether (Ether), and mixed solvents thereof.

1 <x <3, 1 <y <3, and 1 <z <3.

In this way the produced three-dimensional hybrid structure is 0.01 to 1.0 being mesopores of micro pore and 0.01 to 1.0 cm ³ / g are formed together in cm ³ / g, the micro pore is formed from 50 to 85% based on the total pore volume . Also, the micropores and the mesopores are formed at a volume ratio of 1: 0.01 to 1.0, preferably 1: 0.2 to 0.4, to form a structure having a large specific surface area.

Further, the three-dimensional hybrid structure has a BET surface area of 500 m ² / g or more, preferably 500 to 2000 m ² / g, and more preferably 600 to 1300 m ² / g.

Further, the present invention is described with reference to Fig. 1, for a method of manufacturing a three-dimensional hybrid structure.

A method for producing a three-dimensional hybrid structure according to the present invention comprises the steps of: (A) adding an exfoliated metal double layer hydroxide (LDH) nanosheet and a ligand to an organic solvent and sonication; And

(B) attaching a metal ion to the ultrasonic treated solution, and performing a self-assembly by reacting the metal ion, the two or more separated metal double-layer hydroxide (LDH) nanosheet surfaces are connected to the metal-organic structure (MOF) So that a three-dimensional hybrid structure formed in a three-dimensional structure can be provided.

First, in step (A), the separated metal double layer hydroxide (LDH) nanosheets and ligands are dissolved in an organic solvent by sonication for 1 to 3 hours.

 The ligand is located on the surface of the peeled metal double layer hydroxide (LDH) nanosheet bearing the surface charge to connect the metal double layer hydroxide (LDH) nanosheets and form the metal-organic structure (MOF) by self-assembly It is to induce something.

The exfoliated metal double layer hydroxide (LDH) nanosheets and ligands are mixed in a weight ratio of 1: 5 to 200, preferably 1:20 to 100. If the content of the ligand is less than the lower limit based on the LDH nanosheet, the metal-organic structure (MOF) may not be formed by self-assembly. If the content exceeds the upper limit, a structure having a large specific surface area can not be formed.

The organic solvent is used for imparting new functionality while having a wide specific surface area of the three-dimensional hybrid structure of the present invention. In particular, a metal-organic structure (MOF) is formed by self- ) To form a three-dimensional hybrid structure so as to hybridize with the LDH nanosheet. Examples of the organic solvent include N, N-dimethyl formamide (DMF), formaldehyde (FA), N, N-Diethyl formamide (DEF), dimethylacetamide , Methanol, MeOH, ethanol, EtOH, tetrahydrofuran, water, H ₂ O, 1-Methyl-2-pyrrolidinone NMP), dimethyl sulfoxide (DMSO), diethyl ether (Ether), and mixed solvents thereof. Preferably, the organic solvent is selected from the group consisting of 1 : 1 to 20 by weight.

Next, in the step (B), a metal-organic structure (MOF) is formed by self-assembly by adding metal ions to the ultrasonic wave treated solution to react the metal-organic structure (MOF) with the LDH nanosheet The resulting three-dimensional hybrid structure is fabricated.

The metal ion is located on the surface of the metal double layer hydroxide (LDH) nanosheet and reacts with a ligand serving as a pillar connecting the LDH nanosheets to induce the formation of a metal-organic structure (MOF) by self-assembly If only one of the metal ion and the ligand is used, a metal-organic structure (MOF) is not formed, so that it is preferable to use a metal ion and a ligand together.

1, the ligand is located on the front surface of each LDH nanosheets, but the self-assembled metal-organic structure (MOF) using the ligand and metal ion as a precursor is formed on a part of the surface of each LDH nanosheet To form a three-dimensional structure by connecting two or more LDH nanosheets.

The metal ion is used in an amount of 5 to 200 parts by weight, preferably 5 to 100 parts by weight based on 1 part by weight of the metal double layer hydroxide (LDH) nanosheet stripped in the step (A). If the content of the metal ion is less than the lower limit based on the LDH nanosheet, the metal-organic structure (MOF) may not be formed by self-assembly. If the content exceeds the upper limit, the structure is not formed in three dimensions, A wide structure can not be manufactured.

The step (B) is carried out at 50 to 200 ° C, preferably at 100 to 150 ° C for 10 to 24 hours, preferably for 14 to 18 hours. When the temperature and time are out of the above range, a three-dimensional hybrid structure may not be formed.

The thus prepared three-dimensional hybrid structure can be used as a photocatalyst capable of decomposing water to produce hydrogen or oxygen.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

Manufacturing example  One. Zn - Cr LDH  synthesis

Zn - Cr LDH  powder

In order to prepare nanosheets, a nitrate form of pure Zn-Cr LDH is required. To synthesize the nanosheets, refer to the previously reported literature (Prevot, V .; Forano, C .; Besse, JP Inorg Chem. 1998, 37, 4293-4301). First, Zn ^{+ 2} at room temperature _{(Zn (NO 3) 2 ·} 6H 2 O, 0.66M), Cr 3 + (Cr (NO 3) 3 · 9H 2 O, 0.33M), NaNO the ₃ (1.98M) 2 molar ratio : 1: 3 in a polar solvent such as water. When coprecipitated, the solution was slowly adjusted to pH 5.5 ± 0.5 with 2M NaOH solution, and N ₂ gas was continuously flown to prevent the formation of LDH in the form of carbonate. After adjusting the pH, the temperature of the solution was maintained at 60 캜 and stirred vigorously for 24 hours. After completion of the reaction, the purple sample was separated through a centrifuge and washed several times to remove the remaining ions without reacting with distilled water. The separated wet powder was dried in an oven at &lt; RTI ID = 0.0 &gt; 60 C &lt; / RTI & Powder.

Zn - Cr LDH  Nanosheet synthesis

(Li, L .; Ma, R .; Ebina, Y .; Iyi, N .; Sasaki, R., et al.) For deriving the synthesized layered structure of Zn-Cr LDH powder into a single LDH nanosheet, T. Chem . Mater. 2005, 17, 4386-4391). LDH powder (0.5 g to 1 g / L) was subjected to vigorous stirring in a formamide solution under continuous bubbling of N 2 gas to obtain a Zn-Cr LDH nanosheet.

Manufacturing example  2. Not stripped  not Carbonate  Form ZnCr - LDH  Produce

In order to produce ZnCr-LDH not to be peeled off, Na ₂ CO ₃ was used instead of NaNO ₃ , and bubbling of N ₂ gas was not performed.

Manufacturing example  3. Ti -MOF manufacture

1.08 g of NH ₂ -BDC was added to and dissolved in 7 ml of a mixed solvent (anhydrous methanol: DMF = 1: 1 by weight), and then 0.51 ml of Ti (BuO) ₄ was added and the mixture was maintained in an oven at 150 ° C. for 16 hours And then cooled at room temperature to obtain a yellow crystalline product, which was then filtered to obtain Ti-MOF.

Example  1. Preparation of Ti-MOF @ ZnCr-LDH (30 mg) three-dimensional hybrid structure

1.08 g of NH ₂ -BDC and 30 mg of ZnCr-LDH nanosheet prepared in Preparation Example 1 were added to 7 ml of a mixed solvent (methanol anhydride: DMF = 1: 1 weight ratio) and sonicated for 2 hours to dissolve The undissolved particles precipitated and only the dissolved solution was transferred to the reactor separately. After to the solution was transferred to the reactor the addition of 0.51 ml of Ti (BuO) ₄ kept in an oven for 16 hours at 150 ℃ was cooled at room temperature, the resulting yellow crystalline product was then filtered. The obtained product was washed with DMF to remove unreacted material, washed with methanol and DMF, and then dried under vacuum to obtain Ti-MOF @ ZnCr-LDH three-dimensional hybrid structure 0.285 g was obtained.

Example  2. Preparation of Ti-MOF @ ZnCr-LDH (100 mg) three-dimensional hybrid structure

The same procedure as in Example 1 was carried out except that 100 mg of ZnCr-LDH was used to obtain a Ti-MOF @ ZnCr-LDH three-dimensional hybrid structure.

Comparative Example  1. General Zn - Cr LDH Fabrication of Three-Dimensional Hybrid Structure

The heterolayered ZCT nanohybrid was synthesized by mixing the unexposed ZnCr-LDH formamide dispersion prepared in Preparation Example 2 and the laminated titanium oxide nanosheet in an N ₂ atmosphere under constant stirring at room temperature . The re-deposited ZCT nanohybrid was recovered by centrifugation at 6,000 rpm, rinsed with formaldehyde and absolute ethanol, and finally vacuum-dried at 65 ° C for 24 hours. The molar ratio of Zn-Cr-LDH to the deposited titanium oxide was adjusted by adjusting the layered layer of the nanosheet based on charge balance (1: 0.91), area balance (1: 1.46) and intermediate composition (1: .

< Test Example >

In Comparative Example 1, the three-dimensional hybrid structure was not fabricated and the experiment was not conducted.

Test Example  One. SEM  shooting

FIG. 3A is a SEM photograph of the surface of a Ti-MOF @ ZnCr-LDH three-dimensional hybrid structure manufactured according to Example 1 of the present invention, and FIG. 3B is a cross- @ ZnCr-LDH The three-dimensional hybrid structure was photographed by SEM.

As shown in FIGS. 3A and 3B, the Ti-MOF @ ZnCr-LDH three-dimensional hybrid structure manufactured according to the first and second embodiments of the present invention is formed into a square plate having a size of several micrometers Respectively.

Test Example  2. Specific surface area  And pore volume measurement

The BET surface area (m ² / g) was measured in accordance with ASTM D3663-03 and the solvent used was 77 K of nitrogen. The straight portion of the BET plot was obtained at a relative pressure of 0.05 to 0.25 and the pore volume was determined from the adsorption branch of the isotherm at a relative pressure (P / Po) of 0.990. The samples were degassed with a dry nitrogen purge for at least 24 hours at 250 캜 before measurement. The micropores mean that the diameter is 0.1-1.9 nm, and the mesopores mean that the diameter is 2.0-50.0 nm.

division BET surface area (m ² / g) Total pore volume (cm ³ / g) Micro pore volume (cm ³ / g) Microporous ratio (%) Mesopore volume (cm ³ / g) Example 1 911 0.4520 0.3534 78.2 0.0986 Example 2 615 0.3075 0.2453 80.0 0.0622

As shown in Table 1 above, the BET surface area of the three-dimensional structure produced according to Examples 1 and 2 of the present invention is 166 m ² / g, which is the BET surface area of the exfoliated Zn-Cr LDH nanosheet prepared in Production Example 1, g, respectively.

Further, as a result of calculation of the micro-pore volume through the t-plot method, the micro-pores occupied 78 to 80% of the total pore volume of the three-dimensional structure manufactured according to Examples 1 and 2, .

Test Example 3. Nitrogen adsorption / desorption measurement

4 is a graph showing N ₂ adsorption-desorption isotherms of a Ti-MOF @ ZnCr-LDH three-dimensional hybrid structure produced according to Examples 1 and 2 of the present invention. The adsorption / desorption isotherms were measured according to ASTM D4222-03.

As shown in FIG. 4, it was confirmed that the Ti-MOF @ ZnCr-LDH three-dimensional hybrid structures of Examples 1 and 2 exhibited remarkable nitrogen adsorption and desorption at a low pressure region and at a high pressure region, and hysteresis, Did not occur.

Test Example 4. Micro pore measurement

FIG. 5 is a graph showing the size distribution of micro pores formed on the Ti-MOF @ ZnCr-LDH three-dimensional hybrid structure produced according to Examples 1 and 2 of the present invention. The size distribution of the micropores was estimated from the nitrogen adsorption experiment at 77K by the Horvath Kawazoe method.

As shown in FIG. 5, the three-dimensional hybrid structures of Example 1 had the largest pore sizes of 0.42 to 0.51 nm, and the three-dimensional hybrid structures of Example 2 had the largest pore sizes of 0.45 to 0.56 nm Respectively.

Test Example 5. Light energy absorption band gap

6A is a diffuse reflection UV-vis absorption spectrum graph of the Ti-MOF prepared according to Production Example 3 of the present invention and the Ti-MOF @ ZnCr-LDH three-dimensional hybrid structure produced according to Example 1 and Example 2, FIG. 6B is an enlarged graph of the absorption spectrum of FIG. 6A. FIG.

As shown in FIGS. 6A and 6B, it was confirmed that the three-dimensional hybrid structure synthesized according to Examples 1 and 2 had a light energy absorption bandgap different from that of Production Example 3 of Ti-MOF. In particular, as shown in FIG. 6B, it was confirmed that the three-dimensional hybrid structures of Examples 1 and 2 exhibited optical energy absorption although they could not absorb the light energy in the 1.8-2.2 eV interval from the Ti-MOF of Production Example 3.

Claims (17)

Two or more separated metal double-layer hydroxide (LDH) nanosheet surfaces are connected by a metal-organic structure (MOF) to form a three-dimensional structure,
The three-dimensional structure is formed by: i) removing the separated metal double layer hydroxide (LDH) nanosheet and a ligand to an organic solvent and performing ultrasonic treatment to prepare a separated metal double layer hydroxide (LDH) nanosheet having a ligand on the surface thereof ii) reacting the metal nanoparticles with a metal ion at a temperature ranging from 50 to 200 ° C to form a metal-organic structure (self-assembled) on the surface of the exfoliated metal double layer hydroxide (LDH) nanosheet MOF)
The organic solvent is selected from the group consisting of N, N-Dimethyl Formamide (DMF), formaldehyde (FA), N, N-Diethyl Formamide (DEF), dimethylacetamide , Methanol, MeOH, ethanol, EtOH, tetrahydrofuran, water, H ₂ O, 1-Methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO), and diethyl ether (Ether) are mixed at a weight ratio of 1: 1-20. delete The method of claim 1, wherein the 3-D hybrid structure is a three-dimensional hybrid structure characterized in that the mesopores of from 0.01 to 1.0 cm ³ / g and micro pores of 0.01 to 1.0 cm ³ / g of formed. ◈ Claim 4 is abandoned due to the registration fee. The three-dimensional hybrid structure according to claim 1, wherein the three-dimensional hybrid structure has micropores and mesopores in a volume ratio of 1: 0.01 to 1.0. ◈ Claim 5 is abandoned due to the registration fee. The three-dimensional hybrid structure according to claim 1, wherein the three-dimensional hybrid structure has a BET surface area of 500 to 2000 m ² / g. 2. The three-dimensional hybrid structure according to claim 1, wherein the exfoliated metal double layer hydroxide (LDH) nanosheet is a compound represented by the following Chemical Formula 1:
[Chemical Formula 1]
[M ^II _(1-x) M ^III _x (OH) ₂ ] [A ^n- ] _{x / n} .zH ₂ O;
In the general formula 1, M ^II is ^{Ca 2 +, Mg 2 +,} Zn 2 +, Ni 2 +, Mn 2 +, Co 2 +, Fe 2 +, Cu 2 + , and selected from the group consisting of mixed metal And,
M ^III is selected from ^{3 +} Fe, Al ^{+ 3,} Cr ^{+ 3,} Mn ^{+ 3,} Ga ^{+ 3,} Co ^{+ 3,} Ni ^{+ 3,} and the group consisting of mixed metal,
A ^n- is selected from the group consisting of hydroxide ions (OH ^- ), nitrate ions (NO ^{3 -} ), PO ₄ ^{3 -} , HPO ₄ ^{2 -} , H ₂ PO ^{4 -}
0 &lt; x &lt; 1, and z is a real number of 0.1 to 15. The method of claim 1, wherein the ligand is selected from the group consisting of 2-aminoterephthalic acid (NH ₂ -H ₂ BDC), terephthalic acid (H ₂ BDC), 2,5-dihydroxyterephthalic acid , the group consisting of _{5-dihydroxyterephthalic acid, H 2 DOBDC} ), trimethoxy siksan (trimesic acid, H ₃ BTC), imidazole (imidazole, IM) and 1-methyl-imidazole _{(1-methyl imidazole, CH 3} -IM) Wherein the three-dimensional hybrid structure is at least one selected from the group consisting of polyolefin and polyolefin. ◈ Claim 8 is abandoned due to the registration fee. The method of claim 1, wherein the metal ions are selected from the group consisting of Li ⁺ , Mg ²⁺ , Al ³⁺ , Ti ²⁺ , Ti ³⁺ , Ti ⁴⁺ , V ³⁺ , V ⁴⁺ , V ⁵⁺ , Cr ²⁺ , Cr ³⁺ , Mn ²⁺ , Mn ³⁺ , Mn ⁴⁺ , Mn ⁶⁺ , Mn ⁷⁺ , Fe ²⁺ , Fe ³⁺ , Co ²⁺ , Co ³⁺ , Ni ²⁺ , Cu ⁺ , Cu ²⁺ , Zn ²⁺ , Ag ^+, and mixed metal ions thereof. (A) adding an exfoliated metal double layer hydroxide (LDH) nanosheet and a ligand, which have a surface charge, to an organic solvent and sonication; And
(B) adding a metal oxide to the ultrasonic treated solution and performing a self-assembly by reacting at 50 to 200 ° C,
The organic solvent is selected from the group consisting of N, N-Dimethyl Formamide (DMF), formaldehyde (FA), N, N-Diethyl Formamide (DEF), dimethylacetamide , Methanol, MeOH, ethanol, EtOH, tetrahydrofuran, water, H ₂ O, 1-Methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO), and diethyl ether (Ether) are mixed at a weight ratio of 1: 1-20 to form two or more separated metal double layers A method for producing a three-dimensional hybrid structure in which a surface of a hydroxide (LDH) nanosheet is connected to a metal-organic structure (MOF) to form a three-dimensional structure. ◈ Claim 10 is abandoned due to the registration fee. 10. The method according to claim 9, wherein the metal double layer hydroxide (LDH) nanosheets and the ligand separated in the step (A) are mixed at a weight ratio of 1: 5 to 200. ◈ Claim 11 is abandoned due to registration fee. The method of claim 9, wherein the ligand in step (A) is selected from the group consisting of 2-aminoterephthalic acid (NH ₂ -H ₂ BDC), terephthalic acid (H ₂ BDC), 2,5- Imidazole (IM), and 1-methyl imidazole (CH ₃ - OH), as well as the reaction products of these compounds, such as 2,5-dihydroxyterephthalic acid (H ₂ DOBDC), trimesic acid (H ₃ BTC), imidazole IM). &Lt; / RTI &gt; delete ◈ Claim 13 is abandoned due to registration fee. The method according to claim 9, wherein the metal nanoparticles used in step (A) and metal ions used in step (B) are mixed in a weight ratio of 1: 5 to 200: Dimensional hybrid structure. ◈ Claim 14 is abandoned due to registration fee. 10. The method of claim 9, wherein the metal ion in the step (B) is ⁺ Li, Mg ^{+ 2,} Al ^{+ 3,} Ti ^{+ 2,} Ti ^{+ 3,} Ti ^4+, V ^{+ 3,} V ^{+ 4,} V ^{+ 5, Cr 2 +, Cr 3 +,} Mn 2 +, Mn 3 +, Mn 4 +, Mn 6 +, Mn 7 +, Fe 2 +, Fe 3 +, Co 2 +, Co 3 +, Ni 2+, Cu + , Cu ^{2 +} , Zn ^{2 +} , Ag ⁺ and mixed metal ions thereof. ◈ Claim 15 is abandoned due to registration fee. 10. The method according to claim 9, wherein the self-assembly is performed at 50 to 200 DEG C for 10 to 24 hours in the step (B). 9. A photocatalyst comprising a three-dimensional hybrid structure according to any one of claims 1 to 8. ◈ Claim 17 is abandoned due to registration fee. 17. The photocatalyst according to claim 16, wherein the photocatalyst is a photocatalyst which decomposes water to generate hydrogen.

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