Carbon hollow sphere / metal organic framework composite material and preparation method thereof

Abstract

The present invention provides a hollow carbon sphere / metal organic framework composite material and a preparation method thereof. The preparation method of the hollow carbon sphere / metal organic framework composite material comprises the following steps: preparing hollow carbon spheres; adding the hollow carbon spheres and an amino modifier at a molar ratio of 500:(5-60) to an alcohol solution, stirring, filtering, washing, and vacuum drying to obtain amination hollow carbon spheres; taking a zirconium salt, an organic ligand, and an organic solvent at a molar ratio of 2:(25-30):(750-1500), adding the zirconium salt and the organic ligand to the organic solvent, then adding the amination hollow carbon spheres, and stirring at room temperature for 30-60 minutes to obtain a mixed solution; transferring the mixed solution to an autoclave, hydroheating at 100-120°C for 1-24 hours, cooling to room temperature, and centrifuging to obtain a powder; washing the powder with an organic solution, and vacuum drying to obtain the hollow carbon sphere / metal organic framework composite material.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and in particular to a carbon hollow sphere / metal organic framework composite material and a preparation method thereof. Background Art

[0002] Volatile organic compounds (VOCs) are gaining increasing attention. VOCs easily enter the human body through the skin, respiratory tract, and digestive tract mucosa, affecting the digestive system and central nervous system, and endangering human health. To reduce VOC emissions and alleviate smog, the development of efficient adsorbents to absorb VOCs is urgently needed.

[0003] Currently, the commonly used methods for treating VOCs include adsorption separation, catalytic combustion, photocatalysis, and biofiltration. Among them, adsorption separation has the advantages of simple process, strong operability, low energy consumption, safety, environmental protection, and easy industrialization.

[0004] In the adsorption separation method, adsorbents are usually used for adsorption, including activated carbon (AC), silica gel (SG), zeolite and metal organic framework (MOFs). Among them, MOFs, as a new type of crystalline porous nanomaterial, is composed of multifunctional ligands and metal ions. Due to its high specific surface area, controllable porosity and high stability, it has become a new functional material for environmental remediation. However, MOFs have low thermal stability, low mechanical properties and are easily affected by water and other chemical solvents. The MOF structure is extremely unstable after exposure to water, and the MOF structure will be partially or completely destroyed under humid or water-containing conditions. Summary of the Invention

[0005] The purpose of the present invention is to provide a carbon hollow sphere / metal organic framework composite material with good stability and a preparation method thereof, so as to solve the problems in the prior art.

[0006] To solve the above technical problems, the present invention provides a method for preparing a hollow carbon sphere / metal organic framework composite material and a preparation method thereof, comprising the following steps:

[0007] Hollow carbon spheres are prepared;

[0008] The hollow carbon spheres and the amino modifier are added to an alcohol solution at a molar ratio of 500:(5-60), stirred at room temperature for 8-12 hours, filtered and washed, and vacuum dried at 70-100° C. for 8-12 hours to obtain aminated hollow carbon spheres; the amino modifier has a structural formula comprising at least one benzene ring, at least one amino group, and at least one carboxyl group;

[0009] A zirconium salt, an organic ligand, and an organic solvent are prepared in a molar ratio of 2:(25-30):(750-1500), the zirconium salt and the organic ligand are added to the organic solvent, and then the aminated hollow carbon spheres are added. The mixture is stirred at room temperature for 30-60 min to obtain a mixed solution. The zirconium salt is tetravalent and can provide lone pairs of electrons, and the organic ligand has a structural formula that includes at least one benzene ring and at least one carboxyl group. The weight ratio of the zirconium salt to the aminated hollow carbon spheres is (2%-10%):1.

[0010] The mixed solution is transferred to a high-pressure reactor, hydroheated at 100-120° C. for 1-24 hours, then cooled to room temperature, and centrifuged to obtain a powder. The powder is washed with an organic solution and vacuum-dried at 40-60° C. for 8-12 hours to obtain a carbon hollow sphere / metal organic framework composite material.

[0011] In one embodiment, the amino modifier includes at least one of 2-aminoterephthalic acid, 4-aminobenzoic acid and 3-aminobenzoic acid.

[0012] In one embodiment, the zirconium salt includes at least one of zirconium tetrachloride, zirconium nitrate, zirconium oxide, zirconium propoxide, zirconium oxychloride and zirconium citrate.

[0013] In one embodiment, the organic ligand comprises at least one of terephthalic acid and benzoic acid;

[0014] The organic solvent includes at least one of N,N-dimethylformamide, diethylformamide and dimethyl sulfoxide.

[0015] In one embodiment, the pore size of the hollow carbon spheres is 5-20 nm, and the particle size is 300-500 nm.

[0016] In one embodiment, the steps of preparing the hollow carbon spheres include:

[0017] An organosilicon source is added to a mixed solution of ethanol, water and NH3·H2O, and after stirring at 10-40°C, resorcinol and formaldehyde are added to the solution, and stirring is continued for 20-24 hours. A precipitate is obtained by centrifugation, and the precipitate is washed several times with water and ethanol, and dried at 40-60°C for 8-12 hours to obtain a composite powder; wherein the molar ratio of organosilicon source: ethanol: water: NH3·H2O: resorcinol: formaldehyde is 10: (650-1800): (300-800): (1000-2200): (1.5-5): (12-20);

[0018] The composite powder is heated from room temperature to 500-1000° C. at a rate of 1-10° C. / min under a protective gas atmosphere, maintained for 3-10 hours, and then cooled to room temperature to obtain a carbonized powder;

[0019] The carbonized powder is dispersed in a solution with a concentration of 5% to 20% HF, stirred at room temperature for 12 to 24 hours, and then the product is collected by centrifugation, washed several times with ethanol and water, and dried at 40 to 60° C. for 8 to 12 hours to obtain the carbon hollow spheres.

[0020] In one embodiment, the organic silicon source includes at least one of tetrabutyl orthosilicate, tetramethoxysilane, tetramethylsilane and monosilane.

[0021] The present invention also provides a carbon hollow sphere / metal organic framework composite material, which is prepared by the above-mentioned method for preparing the carbon hollow sphere / metal organic framework composite material.

[0022] It can be seen from the above technical solution that the advantages and positive effects of the present invention are:

[0023] The carbon hollow sphere / metal organic framework composite material and its preparation method in the present invention first prepare amino-treated carbon hollow spheres, and then attach a coordination compound formed by metal ions and organic ligands to the amino-treated carbon hollow spheres to form a carbon hollow sphere / metal organic framework composite material, thereby improving the thermal stability of the entire composite material and making the composite material have excellent adsorption properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic flow chart of the preparation method of the carbon hollow sphere / metal skeleton composite material of the present invention.

[0025] Figure 2 1 and 2. These are the XRD patterns of the hollow carbon spheres, the aminated hollow carbon spheres, and the hollow carbon sphere / metal skeleton composite material in Example 1 of the present invention.

[0026] Figure 3 This is the SEM image of Example 1 of the present invention.

[0027] Figure 4 This is the SEM image of Example 2 of the present invention.

[0028] Figure 5 This is the SEM image of Example 3 of the present invention. DETAILED DESCRIPTION

[0029] Typical embodiments embodying the features and advantages of the present invention are described in detail in the following description. It should be understood that the present invention is capable of various variations in different embodiments without departing from the scope of the present invention, and that the descriptions and illustrations herein are intended to be illustrative rather than limiting.

[0030] In order to further illustrate the principle and structure of the present invention, preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0031] The present invention provides a carbon hollow sphere / metal organic framework composite material and a preparation method thereof. A coordination compound formed by metal ions and organic ligands is attached to the carbon hollow sphere to form a carbon hollow sphere / metal organic framework composite material, thereby improving the thermal stability of the entire composite material and making the composite material have excellent adsorption performance.

[0032] Figure 1 A schematic diagram showing a process for preparing a carbon hollow sphere / metal skeleton composite material is shown. Figure 1 , including the following steps:

[0033] S1. Prepare carbon hollow spheres.

[0034] Hollow carbon materials have good thermal and chemical stability, good thermal and electrical conductivity, sufficient mechanical strength and elasticity, low density, very high specific surface area and large pore volume. They also show better stability to water and corrosive gases such as H2S and SO2, and have better VOCs mass transfer capabilities than microporous carbon materials, and provide more abundant adsorption sites after amination.

[0035] The pore size of the carbon hollow sphere is 5-20 nm, and the particle size is 300-500 nm. The above pore size and particle size ensure the specific surface area and pore volume of the final carbon hollow sphere / metal skeleton composite material.

[0036] Specifically, the steps of preparing hollow carbon spheres include the following:

[0037] S11. Add an organosilicon source to a mixed solution of ethanol, water and NH3·H2O, stir evenly at 10-40°C, add resorcinol and formaldehyde to the solution, continue stirring for 20-24 hours, obtain a precipitate by centrifugal separation, wash it with water and ethanol several times, and dry it at 40-60°C for 8-12 hours to obtain a composite powder; wherein the molar ratio of organosilicon source: ethanol: water: NH3·H2O: resorcinol: formaldehyde is 10: (650-1800): (300-800): (1000-2200): (1.5-5): (12-20).

[0038] Specifically, the core-shell structure of resorcinol-formaldehyde (RF)@silica, namely RF@SiO2, is prepared in this step.

[0039] The organic silicon source includes at least one of tetrabutyl orthosilicate, tetramethoxysilane, tetramethylsilane and monosilane.

[0040] S12. In an atmosphere of protective gas, the composite powder is heated from room temperature to 500-1000° C. at a rate of 1-10° C. / min, maintained for 3-10 hours, and then cooled to room temperature to obtain carbonized powder.

[0041] Specifically, this step is used to carbonize RF to obtain C@SiO2.

[0042] S13. Disperse the carbonized powder in a solution with a concentration of 5% to 20% HF, stir at room temperature for 12 to 24 hours, then collect the product by centrifugation, wash it with ethanol and water several times, and dry it at 40 to 60° C. for 8 to 12 hours to obtain carbon hollow spheres.

[0043] Specifically, this step is used to etch away SiO2 to obtain carbon hollow spheres.

[0044] The HF solution penetrates the micropores on the surface of the carbon spheres and reacts with SiO2, thereby etching away SiO2.

[0045] S2. Adding hollow carbon spheres and an amino modifier in a molar ratio of 500:(5-60) to an alcohol solution, stirring at room temperature for 8-12 hours, filtering and washing, and vacuum drying at 70-100° C. for 8-12 hours to obtain aminated hollow carbon spheres; the structural formula of the amino modifier includes at least one benzene ring, at least one amino group, and at least one carboxyl group.

[0046] The amino and carboxyl groups in the amino modifier are used to form coordination atoms. There are a large number of hydroxyl groups on the surface of the hollow carbon spheres. The amino and carboxyl groups combine with the hydroxyl groups on the surface of the hollow carbon spheres, adsorbing the amino groups on the outer surface of the hollow carbon spheres, thereby forming functionalized hollow carbon spheres.

[0047] Specifically, the amino modifier includes at least one of 2-aminoterephthalic acid, 4-aminobenzoic acid, and 3-aminobenzoic acid.

[0048] S3. Take a zirconium salt, an organic ligand and an organic solvent in a molar ratio of 2:(25-30):(750-1500), add the zirconium salt and the organic ligand to the organic solvent, then add the amino-treated hollow carbon spheres, and stir at room temperature for 30-60 minutes to obtain a mixed solution; the zirconium salt is tetravalent and can provide lone pairs of electrons, and the structural formula of the organic ligand includes at least one benzene ring and at least one carboxyl group; the weight ratio of the zirconium salt to the amino-treated hollow carbon spheres is (2%-10%):1.

[0049] Specifically, the zirconium salt includes at least one of zirconium tetrachloride, zirconium nitrate, zirconium oxide, zirconium propoxide, zirconium oxychloride, and zirconium citrate.

[0050] The organic ligand includes at least one of terephthalic acid and benzoic acid.

[0051] The organic solvent includes at least one of N,N-dimethylformamide, diethylformamide and dimethyl sulfoxide, and has a polarity of about 2-10.

[0052] S4. Transfer the mixed solution to a high-pressure reactor, hydroheat it at 100-120° C. for 1-24 hours, then cool it to room temperature, and centrifuge to obtain a powder. Wash the powder with an organic solution, and vacuum dry it at 40-60° C. for 8-12 hours to obtain a carbon hollow sphere / metal organic framework composite material.

[0053] During the hydrothermal process, the amino groups on the surface of the carbon spheres, like the organic ligands, provide lone pairs of electrons to form coordination compounds with the empty orbitals provided by the metal ions and attach to the carbon hollow spheres, combining the advantages of the metal skeleton and the carbon hollow spheres, thereby improving the thermal stability of the composite material, increasing the specific surface area, pore volume and pore size, and giving the composite material excellent adsorption properties.

[0054] The present invention also provides a carbon hollow sphere / metal skeleton composite material, which is prepared by the above method for preparing the carbon hollow sphere / metal skeleton composite material.

[0055] The inventors of the present application have strictly designed the content of each component and the carbon hollow sphere / metal skeleton composite material with excellent adsorption performance in each step. The method is described below through various embodiments.

[0056] Example 1

[0057] The preparation method of the hollow carbon sphere / metal skeleton composite material in this embodiment comprises the following steps:

[0058] Sa1. Prepare carbon hollow spheres.

[0059] Tetrabutyl orthosilicate was added to a mixed solution of ethanol, water, and NH3·H2O. After stirring at 40°C, resorcinol and formaldehyde were added to the solution and stirred for 24 hours. The precipitate was separated by centrifugation, washed several times with water and ethanol, and dried at 60°C for 8 hours to obtain a composite powder. The molar ratio of tetrabutyl orthosilicate: ethanol: water: NH3·H2O: resorcinol: formaldehyde was 10:1800:800:2200:5:20.

[0060] The composite powder was heated from room temperature to 700°C at a rate of 10°C / min under a nitrogen atmosphere, maintained for 5 hours, and then cooled to room temperature to obtain carbonized powder.

[0061] The carbonized powder was dispersed in a 20% HF solution and stirred at room temperature for 12 h. The product was then collected by centrifugation, washed several times with ethanol and water, and dried at 60 °C for 8 h to obtain carbon hollow spheres.

[0062] Sa2. Add the hollow carbon spheres and the amino modifier 2-aminoterephthalic acid into the alcohol solution at a molar ratio of 500:60, stir at room temperature for 12 hours, filter and wash, and vacuum dry at 100°C for 8 hours to obtain amino-modified hollow carbon spheres.

[0063] Sa3. Zirconium tetrachloride, terephthalic acid, and N,N-dimethylamide in a molar ratio of 2:30:1500 are added to the N,N-dimethylamide, followed by the addition of the aminated hollow carbon spheres. The mixture is stirred at room temperature for 30 minutes to obtain a mixed solution. The weight ratio of zirconium tetrachloride to aminated hollow carbon spheres is 10%:1.

[0064] Sa4. Transfer the mixed solution to a high-pressure reactor, hydroheat it at 100°C for 24 hours, then cool it to room temperature, and centrifuge to obtain a powder. Wash the powder with an organic solution, and vacuum dry it at 60°C for 8 hours to obtain a carbon hollow sphere / metal organic framework composite material.

[0065] Example 2

[0066] The preparation method of the hollow carbon sphere / metal skeleton composite material in this embodiment comprises the following steps:

[0067] Sb1. Prepare carbon hollow spheres.

[0068] Tetramethoxysilane was added to a mixed solution of ethanol, water, and NH3·H2O. After stirring at 10°C, resorcinol and formaldehyde were added to the solution and stirring continued for 20 hours. The precipitate was separated by centrifugation, washed several times with water and ethanol, and dried at 40°C for 12 hours to obtain a composite powder. The molar ratio of tetramethoxysilane: ethanol: water: NH3·H2O: resorcinol: formaldehyde was 10:650:300:1000:1.5:12.

[0069] The composite powder was heated from room temperature to 500° C. at a rate of 1° C. / min under a nitrogen atmosphere, maintained for 10 h, and then cooled to room temperature to obtain carbonized powder.

[0070] The carbonized powder was dispersed in a 5% HF solution and stirred at room temperature for 24 h. The product was then collected by centrifugation, washed with ethanol and water several times, and dried at 40 °C for 12 h to obtain carbon hollow spheres.

[0071] Sb2. The carbon hollow spheres and the amino modifier 4-aminobenzoic acid were added to the alcohol solution at a molar ratio of 500:5, stirred at room temperature for 8 hours, filtered and washed, and vacuum dried at 70°C for 12 hours to obtain amino-modified carbon hollow spheres.

[0072] Sb3, zirconium nitrate, benzoic acid, and diethylformamide in a molar ratio of 2:25:750, the zirconium nitrate and benzoic acid are added to diethylformamide, and then the aminated hollow carbon spheres are added. After stirring at room temperature for 60 minutes, a mixed solution is obtained. The weight ratio of zirconium nitrate to aminated hollow carbon spheres is 2%:1.

[0073] Sb4. The mixed solution was transferred to a high-pressure reactor, hydroheated at 120°C for 1 hour, then cooled to room temperature, and centrifuged to obtain a powder. The powder was washed with an organic solution and vacuum-dried at 40°C for 12 hours to obtain a carbon hollow sphere / metal organic framework composite material.

[0074] Example 3

[0075] The preparation method of the hollow carbon sphere / metal skeleton composite material in this embodiment comprises the following steps:

[0076] Sc1. Prepare hollow carbon spheres.

[0077] Tetramethylsilane was added to a mixed solution of ethanol, water, and NH3·H2O. After stirring at 20°C, resorcinol and formaldehyde were added to the solution and stirred for 21 hours. The precipitate was separated by centrifugation, washed several times with water and ethanol, and dried at 50°C for 10 hours to obtain a composite powder. The molar ratio of tetramethylsilane: ethanol: water: NH3·H2O: resorcinol: formaldehyde was 10:1000:400:1500:3:16.

[0078] The composite powder was heated from room temperature to 800° C. at a rate of 5° C. / min under a nitrogen atmosphere, maintained for 6 h, and then cooled to room temperature to obtain carbonized powder.

[0079] The carbonized powder was dispersed in a 10% HF solution and stirred at room temperature for 16 h. The product was then collected by centrifugation, washed with ethanol and water several times, and dried at 50 °C for 10 h to obtain carbon hollow spheres.

[0080] Sc2. Add the hollow carbon spheres and the amino modifier 4-aminobenzoic acid at a molar ratio of 500:25 to the alcohol solution, stir at room temperature for 10 hours, filter and wash, and vacuum dry at 80° C. for 9 hours to obtain aminated hollow carbon spheres.

[0081] Sc3. Zirconium oxychloride, terephthalic acid, and dimethyl sulfoxide (DMSO) in a molar ratio of 2:28:800 are added to DMSO, followed by addition of the aminated hollow carbon spheres. The mixture is stirred at room temperature for 40 minutes to obtain a mixed solution. The weight ratio of zirconium oxychloride to aminated hollow carbon spheres is 5%:1.

[0082] Sc4. Transfer the mixed solution to a high-pressure reactor, hydroheat it at 110°C for 10 hours, then cool it to room temperature, and centrifuge to obtain a powder. Wash the powder with an organic solution and vacuum dry it at 50°C for 10 hours to obtain a carbon hollow sphere / metal organic framework composite material.

[0083] Example 4

[0084] The preparation method of the hollow carbon sphere / metal skeleton composite material in this embodiment comprises the following steps:

[0085] Sd1. Prepare carbon hollow spheres.

[0086] Monosilane was added to a mixed solution of ethanol, water, and NH3·H2O. After stirring at 30°C, resorcinol and formaldehyde were added to the solution and stirred for 23 hours. The precipitate was separated by centrifugation, washed several times with water and ethanol, and dried at 45°C for 11 hours to obtain a composite powder. The molar ratio of monosilane: ethanol: water: NH3·H2O: resorcinol: formaldehyde was 10:1200:600:1800:4:15.

[0087] The composite powder was heated from room temperature to 1000° C. at a rate of 8° C. / min under a nitrogen atmosphere, maintained for 3 h, and then cooled to room temperature to obtain carbonized powder.

[0088] The carbonized powder was dispersed in a 15% HF solution and stirred at room temperature for 20 h. The product was then collected by centrifugation, washed with ethanol and water several times, and dried at 55 °C for 9 h to obtain carbon hollow spheres.

[0089] Sd2. The carbon hollow spheres and the amino modifier 3-aminobenzoic acid were added to the alcohol solution at a molar ratio of 500:40, stirred at room temperature for 9 hours, filtered and washed, and vacuum dried at 80°C for 5 hours to obtain amino-modified carbon hollow spheres.

[0090] Sd3, zirconium propoxide, benzoic acid, and N,N-dimethylamide in a molar ratio of 2:26:1200, zirconium propoxide and benzoic acid were added to N,N-dimethylamide, and then the aminated hollow carbon spheres were added. After stirring at room temperature for 50 minutes, a mixed solution was obtained. The weight ratio of zirconium propoxide to aminated hollow carbon spheres was 8%:1.

[0091] Sd4. The mixed solution was transferred to a high-pressure reactor, hydroheated at 105°C for 15 hours, then cooled to room temperature, and centrifuged to obtain a powder. The powder was washed with an organic solution and vacuum-dried at 55°C for 11 hours to obtain a carbon hollow sphere / metal organic framework composite material.

[0092] Example 5

[0093] The preparation method of the hollow carbon sphere / metal skeleton composite material in this embodiment comprises the following steps:

[0094] Se1. Prepare carbon hollow spheres.

[0095] Tetrabutyl orthosilicate was added to a mixed solution of ethanol, water, and NH3·H2O. After stirring at 25°C, resorcinol and formaldehyde were added to the solution and stirring continued for 24 hours. The precipitate was separated by centrifugation, washed several times with water and ethanol, and dried at 60°C for 8 hours to obtain a composite powder. The molar ratio of tetrabutyl orthosilicate: ethanol: water: NH3·H2O: resorcinol: formaldehyde was 10:800:500:2000:3.5:18.

[0096] The composite powder was heated from room temperature to 900° C. at a rate of 6° C. / min under a nitrogen atmosphere, maintained for 4 h, and then cooled to room temperature to obtain carbonized powder.

[0097] The carbonized powder was dispersed in a solution with a concentration of 8% HF and stirred at room temperature for 15 h. The product was then collected by centrifugation, washed several times with ethanol and water, and dried at 60 °C for 8 h to obtain carbon hollow spheres.

[0098] Se2. Add the carbon hollow spheres and the amino modifier 2-aminoterephthalic acid into the alcohol solution at a molar ratio of 500:50, stir at room temperature for 12 hours, filter and wash, and vacuum dry at 100°C for 5 hours to obtain amino-modified carbon hollow spheres.

[0099] Se3, zirconium oxide, terephthalic acid, and N,N-dimethylamide in a molar ratio of 2:27:1000, zirconium oxide and terephthalic acid are added to N,N-dimethylamide, and then aminated hollow carbon spheres are added. After stirring at room temperature for 30-60 minutes, a mixed solution is obtained. The weight ratio of zirconium oxide to aminated hollow carbon spheres is 6%:1.

[0100] Se4. Transfer the mixed solution to a high-pressure reactor, hydroheat it at 100°C for 24 hours, then cool it to room temperature, and centrifuge to obtain a powder. Wash the powder with an organic solution and vacuum dry it at 60°C for 8 hours to obtain a carbon hollow sphere / metal organic framework composite material.

[0101] Example 6

[0102] The preparation method of the hollow carbon sphere / metal skeleton composite material in this embodiment comprises the following steps:

[0103] Sf1. Prepare carbon hollow spheres.

[0104] Tetrabutyl orthosilicate was added to a mixed solution of ethanol, water, and NH3·H2O. After stirring at 40°C, resorcinol and formaldehyde were added to the solution and stirring continued for 24 hours. The precipitate was separated by centrifugation, washed several times with water and ethanol, and dried at 60°C for 8 hours to obtain a composite powder. The molar ratio of tetrabutyl orthosilicate: ethanol: water: NH3·H2O: resorcinol: formaldehyde was 10:1800:800:2200:2:14.

[0105] The composite powder was heated from room temperature to 600° C. at a rate of 2° C. / min under a nitrogen atmosphere, maintained for 9 h, and then cooled to room temperature to obtain carbonized powder.

[0106] The carbonized powder was dispersed in a 12% HF solution and stirred at room temperature for 18 h. The product was then collected by centrifugation, washed with ethanol and water several times, and dried at 60 °C for 8 h to obtain carbon hollow spheres.

[0107] Sf2. Add the carbon hollow spheres and the amino modifier 2-aminoterephthalic acid into the alcohol solution at a molar ratio of 500:30, stir at room temperature for 12 hours, filter and wash, and vacuum dry at 100°C for 5 hours to obtain amino-modified carbon hollow spheres.

[0108] Sf3, zirconium citrate, terephthalic acid, and N,N-dimethylamide in a molar ratio of 2:29:900, the zirconium citrate and terephthalic acid are added to the N,N-dimethylamide, and then the aminated hollow carbon spheres are added. After stirring at room temperature for 35 minutes, a mixed solution is obtained. The weight ratio of zirconium citrate to aminated hollow carbon spheres is 4%:1.

[0109] Sf4. The mixed solution was transferred to a high-pressure reactor, hydroheated at 100°C for 24 hours, then cooled to room temperature, and centrifuged to obtain a powder. The powder was washed with an organic solution and vacuum-dried at 45°C for 12 hours to obtain a carbon hollow sphere / metal organic framework composite material.

[0110] Comparative Example 1

[0111] The preparation method of the metal organic framework material in this embodiment includes the following steps:

[0112] Zirconium tetrachloride, terephthalic acid and N,N-dimethylamide in a molar ratio of 2:30:1500 were added to N,N-dimethylamide, and stirred at room temperature for 30 minutes to obtain a mixed solution.

[0113] The mixed solution was transferred to a high-pressure reactor, hydroheated at 100°C for 24 hours, then cooled to room temperature, and centrifuged to obtain a powder. The powder was washed with an organic solution and vacuum-dried at 60°C for 8 hours to obtain a carbon hollow sphere / metal organic framework composite material.

[0114] The adsorption performance of the materials of Examples 1 to 6 and Comparative Example 1 was tested respectively, and the results are shown in Table 1.

[0115] The static adsorption test is performed as follows: a desiccant containing an appropriate amount of adsorbate (toluene) is placed in a constant-temperature water bath. A certain mass of pretreated adsorbent is weighed into a weighing bottle and placed above the desiccant partition. The desiccant lid is then closed to ensure full contact between the adsorbate and the adsorbent at 25°C for 24 hours. The change in mass of the adsorbate before and after adsorption is measured using an analytical balance, and the adsorption capacity of the adsorbent is then determined. The adsorption capacity of the adsorbent can be calculated using the following formula:

[0116]

[0117] Where X represents the adsorption capacity of the adsorbent, m1 and m2 represent the mass of the adsorbent before and after adsorption, respectively.

[0118] The dynamic adsorption test method is as follows: The dynamic adsorption experiment is measured using a plug flow experimental device. Approximately 0.3g of sample is placed in a fixed bed reactor. Before the adsorption experiment, the sample is pretreated overnight under vacuum conditions at 100°C to remove adsorbed water vapor and small molecular organic matter. Before the experiment, the flow rate of the mixed gas of air and n-hexane is adjusted to 0.03L / min, and the concentration of n-hexane is maintained at 0.25g / L. The adsorption amount is measured by gas chromatography (GC), and the dynamic adsorption capacity (q) is measured based on the breakthrough curve. The calculation formula is as follows:

[0119]

[0120] The time tq is calculated as follows:

[0121]

[0122] Among them C A and C0 represent the outlet and inlet concentrations respectively, t D is the dead time of the device and is also a correction factor representing the time during which the adsorbent is not adsorbed from the saturator valve of the detector.

[0123] Stability testing is performed as follows: After a single static adsorption run, the powder sample is placed in an uncovered weighing bottle (50 mm x 30 mm). The sample is heated to 100°C for at least 2 hours under a high vacuum of 0.9 mbar to remove impurities. After this, static adsorption is repeated, and regeneration is recorded. The number of regenerations can be determined.

[0124] Table 1 Properties of carbon hollow sphere / metal organic framework composites

[0125] Examples and Comparative Examples Static adsorption capacity Dynamic adsorption capacity stability Example 1 0.362g / g 0.284g / g Regeneration 4 times Example 2 1.034g / g 0.989g / g Regeneration 6 times Example 3 0.725g / g 0.685g / g Regeneration 8 times Example 4 0.568g / g 0.473g / g Regeneration 5 times Example 5 0.652g / g 0.601g / g Regeneration 5 times Example 6 0.879g / g 0.854g / g Regeneration 6 times Comparative Example 1 0.220g / g 0.14g / g Regeneration 3 times

[0126] From the test data in the above table, it can be seen that due to the addition of carbon hollow spheres, the adsorption capacity of UIO-66 has been improved to a certain extent, and the regeneration performance has also been improved.

[0127] Figure 2 These are the XRD patterns of HCNS, UIO-66, and HCNS-NH2 / UIO-66. It can be seen from the figure that the structure of UIO-66 is not destroyed with the addition of hollow carbon spheres.

[0128] Figure 3 、 Figure 4 and Figure 5 The SEM images of Example 1, Example 2 and Example 3 are shown respectively. Figure 3 It can be seen that the carbon hollow spheres were successfully synthesized. Figure 4 and Figure 5 It shows that when a certain amount of amino-modified carbon spheres are compounded with UIO-66, the adsorption capacity of UIO-66 is improved to a certain extent, and the regeneration performance is also improved.

[0129] While the present invention has been described with reference to several exemplary embodiments, it should be understood that the terms used are intended to be illustrative and exemplary rather than restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope of the appended claims. All changes and modifications that fall within the scope of the claims or their equivalents are intended to be covered by the appended claims.

Claims

1. A method for preparing a hollow carbon sphere / metal organic framework composite material, characterized in that: The following steps are involved: Hollow carbon spheres are prepared; the hollow carbon spheres have hydroxyl groups on their surfaces; The hollow carbon spheres and the amino modifier are added to an alcohol solution at a molar ratio of 500:(5-60), stirred at room temperature for 8-12 hours, filtered and washed, and vacuum dried at 70-100° C. for 8-12 hours to obtain aminated hollow carbon spheres; the amino modifier has a structural formula comprising at least one benzene ring, at least one amino group, and at least one carboxyl group; A zirconium salt, an organic ligand, and an organic solvent are prepared in a molar ratio of 2:(25-30):(750-1500), the zirconium salt and the organic ligand are added to the organic solvent, and then the aminated hollow carbon spheres are added. The mixture is stirred at room temperature for 30-60 min to obtain a mixed solution. The zirconium salt is tetravalent and can provide a lone pair of electrons. The structural formula of the organic ligand includes at least one benzene ring and at least one carboxyl group. The weight ratio of the zirconium salt to the aminated hollow carbon spheres is (2%-10%):1; The mixed solution was transferred to a high-pressure reactor, hydroheated at 100-120°C for 1-24 hours, then cooled to room temperature, and centrifuged to obtain a powder. The powder was washed with an organic solution and vacuum-dried at 40-60°C for 8-12 hours to obtain a carbon hollow sphere / metal organic framework composite material.

2. The method for preparing the hollow carbon sphere / metal organic framework composite material according to claim 1, characterized in that: The amino modifier includes at least one of 2-aminoterephthalic acid, 4-aminobenzoic acid, and 3-aminobenzoic acid.

3. The method for preparing the hollow carbon sphere / metal organic framework composite material according to claim 1, characterized in that: The zirconium salt includes at least one of zirconium tetrachloride, zirconium nitrate, zirconium oxide, zirconium propoxide, zirconium oxychloride and zirconium citrate.

4. The method for preparing the hollow carbon sphere / metal organic framework composite material according to claim 1, wherein: The organic ligand includes at least one of terephthalic acid and benzoic acid; The organic solvent includes at least one of N,N-dimethylformamide, diethylformamide and dimethyl sulfoxide.

5. The method for preparing the hollow carbon sphere / metal organic framework composite material according to claim 1, characterized in that: The pore diameter of the carbon hollow sphere is 5-20 nm, and the particle diameter is 300-500 nm.

6. The method for preparing the hollow carbon sphere / metal organic framework composite material according to claim 1, characterized in that: The steps of preparing the hollow carbon spheres include: An organosilicon source is added to a mixed solution of ethanol, water and NH3·H2O, and after stirring at 10-40°C, resorcinol and formaldehyde are added to the solution, and stirring is continued for 20-24 hours. A precipitate is obtained by centrifugation, and the precipitate is washed several times with water and ethanol, and dried at 40-60°C for 8-12 hours to obtain a composite powder; wherein the molar ratio of organosilicon source: ethanol: water: NH3·H2O: resorcinol: formaldehyde is 10: (650-1800): (300-800): (1000-2200): (1.5-5): (12-20); The composite powder is heated from room temperature to 500-1000° C. at a rate of 1-10° C. / min under a protective gas atmosphere, maintained for 3-10 hours, and then cooled to room temperature to obtain a carbonized powder; The carbonized powder was dispersed in a solution with a concentration of 5% to 20% HF, stirred at room temperature for 12 to 24 hours, and then the product was collected by centrifugation, washed several times with ethanol and water, and dried at 40 to 60 °C for 8 to 12 hours to obtain the carbon hollow spheres.

7. The method for preparing the hollow carbon sphere / metal organic framework composite material according to claim 6, characterized in that: The organic silicon source includes at least one of tetrabutyl orthosilicate, tetramethoxysilane, tetramethylsilane and monosilane.

8. A hollow carbon sphere / metal organic framework composite material, characterized in that: The hollow carbon sphere / metal organic framework composite material is prepared by the preparation method of the hollow carbon sphere / metal organic framework composite material according to any one of claims 1 to 7.

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