An ionic liquid modified MOFs composite material and its preparation method and application

Abstract

The present invention relates to the field of adsorption material technology, and discloses an ionic liquid modified MOFs composite material, a preparation method thereof, and an application thereof. The BET specific surface area of ​​the composite material is 600-1500m 2 / g, and the total pore volume of the composite material is 0.25-0.6cm 3 / g; the composite material includes an activated MOFs material and an ionic liquid loaded on the activated MOFs material, wherein the loading amount of the ionic liquid is 9-60wt%; the activated MOFs material is obtained by subjecting the raw MOFs material to an activation treatment, and the MOFs material is selected from at least one of MOF-508, ZIF-8, MAF-7, and MAF-4. The ionic liquid-modified MOFs composite material provided by the present invention has the characteristics of large adsorption volume and high gas selectivity.

Description

Technical Field

[0001] The present invention relates to the technical field of adsorption materials, and in particular to an ionic liquid modified MOFs composite material and a preparation method and application thereof. Background Art

[0002] Hydrogen sulfide is highly harmful to the human body. Low concentrations can cause fever, dizziness, and breathing difficulties, while high concentrations can lead to asphyxiation. In industry, the acidity and corrosiveness of hydrogen sulfide can severely corrode equipment and pipelines, rendering most catalysts ineffective. The combustion products of hydrogen sulfide in natural gas and petroleum gas, when released into the atmosphere, can form acid rain.

[0003] Currently, H2S capture and removal technologies can be divided into two categories: dry and wet methods. Wet methods include alcoholamine solution absorption, ionic liquid methods, and biological desulfurization. Wet methods are mainly used in desulfurization applications with high sulfur content and large scale.

[0004] Therefore, it is particularly important to develop porous adsorption materials with stable pore structure, high specific surface area and unique surface chemical properties for deep removal of hydrogen sulfide.

[0005] Commonly used porous adsorption materials include activated carbon, zeolite molecular sieves, carbon nanotubes, metal oxides, etc. This type of adsorbent has good thermal stability, but has low processing capacity, long adsorption time, low adsorption efficiency, and poor adsorption selectivity.

[0006] Metal-organic frameworks (MOFs) are a new class of porous materials composed of metal ions or clusters and organic ligands. They possess tunable pore sizes, high specific surface areas and adsorption capacities, and excellent thermal stability and chemical resistance. These structures and properties hold great potential for MOFs in gas adsorption applications, but their selectivity for gas adsorption is limited.

[0007] Researchers have developed a variety of methods to enhance the selective adsorption ability of MOFs materials for mixed gases. For example, modifying the pores with alkaline molecules at unsaturated metal sites can effectively improve the adsorption rate and selectivity of MOFs materials.

[0008] CN108192109A discloses a method for enhancing the stability of metal-organic framework materials using ionic liquids. The method uses an ionic liquid solution as a precursor solution, and MOFs material is added to the precursor solution. The ionic liquid enters the pores of the MOFs material and covers the sites in the MOFs material that are easily reactive with water, preventing water molecules from directly contacting the metal-organic framework material, thereby reducing the hydrolysis rate of the metal-organic framework material and improving water stability.

[0009] However, since the ionic liquid in this method enters the pores of the MOFs material and occupies part of the pore volume, the resulting composite material has a larger loss of pore volume compared to the MOFs material, resulting in a significant reduction in gas adsorption capacity. Summary of the Invention

[0010] The purpose of the present invention is to solve the problem in the prior art that ionic liquid modified MOFs materials have small adsorption capacity and low adsorption selectivity for gases such as hydrogen sulfide.

[0011] During their research, the inventors discovered that modifying activated MOFs with a specific type of ionic liquid prevents the ionic liquid from entering the pores of the MOFs, preventing pore volume loss. This effectively preserves the gas adsorption capacity of the MOFs while also improving adsorption selectivity. Based on this discovery, the inventors developed this solution.

[0012] In order to achieve the above object, the present invention provides an ionic liquid modified MOFs composite material in the first aspect, wherein the BET specific surface area of ​​the composite material is 600-1500m 2 / g, and the total pore volume of the composite material is 0.25-0.6cm 3 / g;

[0013] The composite material comprises an activated MOFs material and an ionic liquid loaded on the activated MOFs material, wherein the loading amount of the ionic liquid is 9-60 wt %;

[0014] The activated MOFs material is obtained by subjecting a raw MOFs material to an activation treatment, and the raw MOFs material is selected from at least one of MOF-508, ZIF-8, MAF-7, and MAF-4;

[0015] The ionic liquid is selected from at least one of 1-hexyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium methanesulfonate, 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-octyl-3-methylimidazolium proline, N-butylpyridinium bis(trifluoromethanesulfonyl)imide, and trihexyltetradecylphosphine bis(trifluoromethylsulfonyl imide).

[0016] The second aspect of the present invention provides a method for preparing the ionic liquid modified MOFs composite material described in the first aspect, the method comprising:

[0017] (1) activating the raw MOFs material to obtain an activated MOFs material;

[0018] (2) contacting and mixing the activated MOFs material with an ionic liquid in the presence of solvent I to obtain a mixed solution;

[0019] (3) Drying the mixed solution.

[0020] The third aspect of the present invention provides the use of the ionic liquid modified MOFs composite material described in the first aspect in the adsorption and removal of hydrogen sulfide.

[0021] The present invention loads the ionic liquid on the activated MOFs material, thereby obtaining an ionic liquid-modified MOFs composite material with large adsorption capacity and high gas selectivity. DETAILED DESCRIPTION

[0022] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0023] In the present invention, unless otherwise specified, the room temperature or normal temperature refers to 25±2°C.

[0024] As mentioned above, the first aspect of the present invention provides an ionic liquid modified MOFs composite material, the BET specific surface area of ​​the composite material is 600-1500m 2 / g, and the total pore volume of the composite material is 0.25-0.6cm 3 / g;

[0025] The composite material comprises an activated MOFs material and an ionic liquid loaded on the activated MOFs material, wherein the loading amount of the ionic liquid is 9-60 wt %;

[0026] The activated MOFs material is obtained by subjecting a raw MOFs material to an activation treatment, and the raw MOFs material is selected from at least one of MOF-508, ZIF-8, MAF-7, and MAF-4;

[0027] The ionic liquid is selected from at least one of 1-hexyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium methanesulfonate, 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-octyl-3-methylimidazolium proline, 1-butyl-3-methylimidazolium hexafluorophosphate, N-butylpyridinium bis(trifluoromethanesulfonyl)imide, and trihexyltetradecylphosphine bis(trifluoromethylsulfonyl imide).

[0028] Preferably, the BET specific surface area of ​​the composite material is 800-1500m 2 / g, and the total pore volume of the composite material is 0.3-0.6cm 3 / g.

[0029] Preferably, the loading amount of the ionic liquid is 15-58 wt%.

[0030] In the present invention, the loading amount of the ionic liquid is calculated as follows: [mass of ionic liquid / (mass of MOFs material+mass of ionic liquid)]×100%.

[0031] The activation treatment conditions in the present invention at least include: vacuum degree of 0.05 MPa to 0.2 MPa, temperature of 120-150° C., and time of 2-5 hours.

[0032] According to a particularly preferred embodiment, the raw MOFs material is MAF-7 and / or MAF-4. The inventors have found that by adopting this preferred embodiment, the obtained composite material has a higher saturated adsorption capacity and selectivity for hydrogen sulfide.

[0033] The present invention has no particular requirements on the source of the raw MOFs material, which can be prepared by methods known in the art or purchased commercially. For example, the MOF-508 can be prepared by referring to the method provided in the literature (Angew. Chem., Int. Ed. 2006, 45, 1390), the ZIF-8 can be prepared by referring to the method provided in the literature (Proc. Natl. Acad. Sci. USA 2006, 103, 10186), and the MAF-7 and MAF-4 can be prepared by referring to the method provided in the literature (Microporous and Mesoporous Materials 157, 42-49).

[0034] According to a particularly preferred embodiment, the ionic liquid is 1-hexyl-3-methylimidazolium acetate and / or 1-butyl-3-methylimidazolium methanesulfonate. The inventors have found that in this preferred embodiment, a composite material with a higher saturated adsorption capacity for hydrogen sulfide can be prepared.

[0035] As mentioned above, the second aspect of the present invention provides a method for preparing the ionic liquid modified MOFs composite material described in the first aspect, the method comprising:

[0036] (1) activating the raw MOFs material to obtain an activated MOFs material;

[0037] (2) contacting and mixing the activated MOFs material with an ionic liquid in the presence of solvent I to obtain a mixed solution;

[0038] (3) Drying the mixed solution.

[0039] Preferably, in step (1), the activation treatment conditions include at least: vacuum degree of 0.05 MPa to 0.2 MPa, temperature of 120-150° C., and time of 2-5 hours.

[0040] More preferably, in step (1), the activation treatment conditions include at least: vacuum degree of 0.05 MPa to 0.2 MPa, temperature of 130-140° C., and time of 3-4 hours.

[0041] Preferably, in step (2), the concentration of the ionic liquid is 0.01-0.1 g / mL, more preferably 0.02-0.06 g / mL. The inventors have found that in this preferred embodiment, the obtained composite material has a higher saturated adsorption capacity for hydrogen sulfide.

[0042] Preferably, in step (2), the weight ratio of the activated MOFs material to the ionic liquid is 1:0.1-1.5, more preferably 1:0.2-1.2.

[0043] Preferably, in step (2), the solvent I is selected from at least one of methanol, ethanol, acetonitrile and acetone.

[0044] Preferably, in step (2), the method further comprises: prior to the contact mixing, subjecting the activated MOFs material and the ionic liquid to ultrasonic treatment.

[0045] Preferably, in step (2), the ultrasonic treatment conditions include at least: ultrasonic frequency of 30-50 kW, temperature of 20-40° C., and time of 20-60 min.

[0046] Preferably, in step (2), the contact mixing conditions include at least: a stirring speed of 200-1000 rpm, a temperature of 20-40° C., and a time of 3-8 hours.

[0047] Preferably, in step (3), the drying treatment conditions include at least: a temperature of 90-120° C. and a time of 10-24 hours.

[0048] As mentioned above, the third aspect of the present invention provides the use of the ionic liquid modified MOFs composite material described in the first aspect in the adsorption and removal of hydrogen sulfide.

[0049] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, all raw materials used are commercially available.

[0050] MAF-7 (hereinafter also referred to as "raw material MOFs material 1") was prepared as follows: an aqueous solution (300 mL) containing 8.4 g of 3-methyl-1,2,4-triazole was added dropwise to an aqueous ammonia solution (25 wt %, 400 mL) containing 14.85 g of Zn(NO3)2·6H2O at room temperature under stirring (stirring speed of 1000 rpm) to obtain a suspension, and the suspension was stirred at 1000 rpm for 7 hours, then filtered, washed with methanol, and dried in air at 80°C for 24 hours;

[0051] Raw material MOFs material 2: Cu-BTC material, purchased from Shanghai Kaishu Chemical Technology Co., Ltd.;

[0052] Ionic liquid 1: 1-hexyl-3-methylimidazolium acetate, purchased from Lanzhou Yulu Ionic Liquid Co., Ltd.

[0053] Ionic liquid 2: 1-butyl-3-methylimidazolium methanesulfonate, purchased from Shanghai Chengjie Chemical Co., Ltd.;

[0054] In the following examples, ethanol and acetonitrile were analytical grade reagents.

[0055] Example 1

[0056] This embodiment provides a method for preparing an ionic liquid modified MOFs composite material, the method comprising the following steps:

[0057] (1) 1 g of raw material MOFs material 1 was placed in a vacuum oven for activation treatment to obtain an activated MOFs material;

[0058] The activation treatment conditions are: vacuum degree of -0.1 MPa, temperature of 140°C, and time of 3 hours;

[0059] (2) adding 1.2 g of ionic liquid 1 to 20 mL of ethanol and stirring uniformly to obtain ionic liquid 1 with a concentration of 0.06 g / mL, then slowly adding the activated MOFs material obtained above to the ionic liquid 1 and performing ultrasonic treatment to obtain a uniform MOFs nanoparticle suspension, and contact mixing the MOFs nanoparticle suspension to obtain a mixed solution;

[0060] The ultrasonic treatment conditions are as follows: ultrasonic frequency of 40 kW, temperature of room temperature, and time of 30 min;

[0061] The contact mixing conditions were: stirring speed of 1000 rpm, temperature of 30°C, and time of 5 hours;

[0062] (3) placing the mixed solution in an oven for drying to obtain an ionic liquid modified MOFs composite material A1;

[0063] The drying conditions are as follows: temperature of 120° C. and time of 16 hours.

[0064] In the ionic liquid modified MOFs composite material A1, the loading amount of the ionic liquid is 55 wt%.

[0065] Example 2

[0066] This embodiment provides a method for preparing an ionic liquid modified MOFs composite material, the method comprising the following steps:

[0067] (1) 1 g of raw material MOFs material 1 was placed in a vacuum oven for activation treatment to obtain an activated MOFs material;

[0068] The activation treatment conditions are: vacuum degree of -0.1 MPa, temperature of 135°C, and time of 4 hours;

[0069] (2) adding 0.9 g of ionic liquid 1 to 22.5 mL of ethanol and stirring uniformly to obtain ionic liquid 1 with a concentration of 0.04 g / mL, then slowly adding the activated MOFs material obtained above to the ionic liquid 1 and performing ultrasonic treatment to obtain a uniform MOFs nanoparticle suspension, and contact mixing the MOFs nanoparticle suspension to obtain a mixed solution;

[0070] The ultrasonic treatment conditions are as follows: ultrasonic frequency of 40 kW, temperature of room temperature, and time of 30 min;

[0071] The contact mixing conditions were: stirring speed of 1000 rpm, temperature of 30°C, and time of 6 hours;

[0072] (3) placing the mixed solution in an oven for drying to obtain an ionic liquid modified MOFs composite material A2;

[0073] The drying conditions are as follows: temperature of 110° C. and time of 20 hours.

[0074] In the ionic liquid modified MOFs composite material A2, the loading amount of the ionic liquid is 47 wt %.

[0075] Example 3

[0076] This embodiment provides a method for preparing an ionic liquid modified MOFs composite material, the method comprising the following steps:

[0077] (1) 1 g of raw material MOFs material 1 was placed in a vacuum oven for activation treatment to obtain an activated MOFs material;

[0078] The activation treatment conditions are: vacuum degree of -0.1 MPa, temperature of 130°C, and time of 3.5 hours;

[0079] (2) adding 0.2 g of ionic liquid 2 to 10 mL of acetonitrile and stirring uniformly to obtain ionic liquid 2 with a concentration of 0.02 g / mL, then slowly adding the activated MOFs material obtained above to the ionic liquid 2 and performing ultrasonic treatment to obtain a uniform MOFs nanoparticle suspension, and contact mixing the MOFs nanoparticle suspension to obtain a mixed solution;

[0080] The ultrasonic treatment conditions are as follows: ultrasonic frequency of 40 kW, temperature of room temperature, and time of 30 min;

[0081] The contact mixing conditions were: stirring speed of 1000 rpm, temperature of 30°C, and time of 7 hours;

[0082] (3) placing the mixed solution in an oven for drying to obtain an ionic liquid modified MOFs composite material A3;

[0083] The drying conditions are as follows: temperature of 115° C. and time of 22 hours.

[0084] In the ionic liquid modified MOFs composite material A3, the loading amount of the ionic liquid is 17 wt %.

[0085] Example 4

[0086] In this example, an ionic liquid-modified MOFs composite material was prepared according to the method of Example 1, except that in step (2), 1.5 g of ionic liquid 1 was added to 25 mL of ethanol and stirred to obtain an ionic liquid 1 with a concentration of 0.06 g / mL.

[0087] The remaining steps were the same as those in Example 1 to obtain an ionic liquid modified MOFs composite material A4.

[0088] In the ionic liquid modified MOFs composite material A4, the loading amount of the ionic liquid is 60 wt %.

[0089] Example 5

[0090] In this example, an ionic liquid modified MOFs composite material was prepared according to the method of Example 1, except that in step (2), the ionic liquid used was 1-butyl-3-methylimidazolium hexafluorophosphate.

[0091] The remaining steps were the same as those in Example 1 to obtain the ionic liquid modified MOFs composite material A5.

[0092] In the ionic liquid modified MOFs composite material A5, the loading amount of the ionic liquid is 55 wt%.

[0093] Example 6

[0094] In this example, an ionic liquid-modified MOFs composite material was prepared according to the method of Example 1, except that in step (2), 1.2 g of ionic liquid 1 was added to 120 mL of ethanol and stirred to obtain an ionic liquid 1 with a concentration of 0.01 g / mL.

[0095] The remaining steps were the same as those in Example 1 to obtain the ionic liquid modified MOFs composite material A6.

[0096] In the ionic liquid modified MOFs composite material A6, the loading amount of the ionic liquid is 55 wt%.

[0097] Example 7

[0098] In this example, an ionic liquid modified MOFs composite material was prepared according to the method of Example 1, except that in step (1), the activation treatment temperature was 150°C.

[0099] The remaining steps were the same as those in Example 1 to obtain the ionic liquid modified MOFs composite material A7.

[0100] In the ionic liquid modified MOFs composite material A7, the loading amount of the ionic liquid is 55 wt%.

[0101] Comparative Example 1

[0102] In this comparative example, an ionic liquid modified MOFs composite material was prepared according to the method of Example 1, except that the raw material MOFs material 1 was not activated;

[0103] The specific steps include:

[0104] (1) adding 1.2 g of ionic liquid 1 to 20 mL of ethanol and stirring uniformly to obtain an ionic liquid 1 with a concentration of 0.06 g / mL, then slowly adding 1 g of raw material MOFs material 1 to the ionic liquid 1 and performing ultrasonic treatment to obtain a uniform MOFs nanoparticle suspension, and contact mixing the MOFs nanoparticle suspension to obtain a mixed solution;

[0105] The ultrasonic treatment conditions are as follows: ultrasonic frequency of 40 kW, temperature of room temperature, and time of 30 min;

[0106] The contact mixing conditions were: stirring speed of 1000 rpm, temperature of 30°C, and time of 5 hours;

[0107] (2) placing the mixed solution in an oven for drying to obtain an ionic liquid modified MOFs composite material DA1;

[0108] The drying conditions are as follows: temperature of 120° C. and time of 16 hours.

[0109] In the ionic liquid modified MOFs composite material DA1, the loading amount of the ionic liquid is 3.14 wt%.

[0110] Comparative Example 2

[0111] In this comparative example, an ionic liquid modified MOFs composite material was prepared according to the method of Example 1, except that in step (1), the raw material MOFs material 1 was replaced with an equal mass of Cu-BTC material;

[0112] The remaining steps were the same as in Example 1 to obtain the ionic liquid modified MOFs composite material DA2.

[0113] In the ionic liquid modified MOFs composite material DA2, the loading amount of the ionic liquid is 2.48 wt%.

[0114] Comparative Example 3

[0115] In this comparative example, an ionic liquid modified MOFs composite material was prepared according to the method of Example 1, except that in step (2), an equal mass of N-methylimidazole tetrafluoroborate was used to replace ionic liquid 1;

[0116] The remaining steps were the same as in Example 1 to obtain the ionic liquid modified MOFs composite material DA3.

[0117] In the ionic liquid modified MOFs composite material DA3, the loading amount of the ionic liquid is 1.55 wt%.

[0118] Test Case

[0119] The adsorption properties of the ionic liquid modified MOFs composite materials prepared in the examples and comparative examples were tested, including the hydrogen sulfide saturated adsorption capacity, specific surface area and pore volume, and the raw material MOFs material 1 was used as a control. The specific results are shown in Table 1.

[0120] Among them, the test method for the saturated adsorption amount of hydrogen sulfide is: use a multi-component competitive adsorption penetration curve analyzer (model BSD-PM, purchased from Beijing Best Instrument Technology Co., Ltd.) to measure the adsorption penetration curve of the sample for hydrogen sulfide gas, and calculate the saturated adsorption amount of hydrogen sulfide per gram of sample.

[0121] The specific operation process is as follows: first, weigh 1g of the sample and activate it at 150℃ for 3h. Then, place the activated sample in a penetration column with an inner diameter of 6mm and a loading height of 60mm. At a gas flow rate of 100ppm and a purge gas of 50ccm, the adsorption penetration curve of hydrogen sulfide on the ionic liquid modified MOFs composite material at normal pressure was obtained.

[0122] The saturated adsorption capacity of the sample for hydrogen sulfide is calculated by formula (I);

[0123]

[0124] In formula (I), q is the adsorption capacity of the adsorbent, mmol / g;

[0125] F is the adsorption gas velocity, L / min;

[0126] c0 is the mass concentration of adsorbate in the feed gas, mol / L;

[0127] t is the adsorption time, min;

[0128] c(t) is the mass concentration of the adsorbate in the tail gas at time t, mol / L;

[0129] m is the adsorbent loading mass, g;

[0130] The specific surface area was tested using a BSD-PM specific surface area and pore size analyzer from Beijing Best Instrument Technology Co., Ltd. The specific test method was as follows: vacuum degassing was performed at 150°C for 12 h, and the sample was transferred to the analysis station after weighing, and the N2 adsorption-desorption isotherm was measured at 77 K; the specific surface area of ​​the sample was calculated by the Brunauer-Emett-Teller (BET) method, and the pore volume of the sample was calculated by the HK (Original) method.

[0131] Table 1

[0132] Example No. Saturated adsorption capacity of hydrogen sulfide, mmol / g <![CDATA[Specific surface area, m 2 / g]]> Pore ​​volume, mL / g Example 1 21.78 826 0.33 Example 2 17.01 956 0.38 Example 3 14.67 1432 0.60 Example 4 11.04 702 0.27 Example 5 13.86 734 0.26 Example 6 3.79 813 0.34 Example 7 6.78 1073 0.40 Comparative Example 1 3.14 702 0.28 Comparative Example 2 2.48 592 0.21 Comparative Example 3 1.55 428 0.19 Raw material MOFs material 1 3.32 1803 0.72

[0133] It can be seen from the results in Table 1 that the saturated adsorption capacity of hydrogen sulfide by the ionic liquid modified MOFs composite material provided by the present invention is significantly increased.

[0134] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. An ionic liquid modified MOFs composite material, characterized in that: The BET specific surface area of ​​the composite material is 600-1500m 2 / g, and the total pore volume of the composite material is 0.25-0.6cm 3 / g; The composite material includes an activated MOFs material and an ionic liquid loaded on the activated MOFs material, wherein the loading amount of the ionic liquid is 9-60 wt %; The activated MOFs material is obtained by subjecting a raw MOFs material to an activation treatment, and the raw MOFs is MAF-7; The activation treatment conditions include at least: vacuum degree of 0.05 MPa to 0.2 MPa, temperature of 120-150° C., and time of 2-5 hours; The ionic liquid is 1-hexyl-3-methylimidazolium acetate and / or 1-butyl-3-methylimidazolium methanesulfonate.

2. The composite material according to claim 1, wherein The BET specific surface area of ​​the composite material is 800-1500 m 2 / g, and the total pore volume of the composite material is 0.3-0.6cm 3 / g.

3. The composite material according to claim 1 or 2, wherein The loading amount of the ionic liquid is 15-58 wt %.

4. A method for preparing the ionic liquid modified MOFs composite material according to any one of claims 1 to 3, characterized in that: The method includes: (1) Activating the raw MOFs material to obtain an activated MOFs material; (2) contacting and mixing the activated MOFs material with an ionic liquid in the presence of solvent I to obtain a mixed solution; (3) Drying the mixed solution.

5. The method according to claim 4, wherein In step (1), the activation treatment conditions include at least: vacuum degree of 0.05 MPa to 0.2 MPa, temperature of 130-140° C., and time of 3-4 hours.

6. The method according to claim 4 or 5, wherein: In step (2), the concentration of the ionic liquid is 0.01-0.1 g / mL.

7. The method according to claim 6, wherein: The concentration of the ionic liquid is 0.02-0.06 g / mL.

8. The method according to claim 4 or 5, wherein: In step (2), the weight ratio of the activated MOFs material to the ionic liquid is 1:0.1-1.

5.

9. The method according to claim 8, wherein In step (2), the weight ratio of the activated MOFs material to the ionic liquid is 1:0.2-1.

2.

10. The method according to claim 4 or 5, wherein: In step (2), the solvent I is selected from at least one of methanol, ethanol, acetonitrile and acetone.

11. The method according to claim 4 or 5, wherein: In step (2), the method further comprises: prior to the contact mixing, ultrasonically treating the activated MOFs material and the ionic liquid.

12. The method according to claim 11, wherein In step (2), the ultrasonic treatment conditions include at least: ultrasonic frequency of 30-50 kW, temperature of 20-40° C., and time of 20-60 min.

13. The method according to claim 4 or 5, wherein: In step (2), the contact mixing conditions include at least: a stirring speed of 200-1000 rpm, a temperature of 20-40° C., and a time of 3-8 hours.

14. The method according to claim 4 or 5, wherein: In step (3), the drying conditions include at least: a temperature of 90-120° C. and a drying time of 10-24 hours.

15. Use of the ionic liquid modified MOFs composite material according to any one of claims 1 to 3 in the adsorption and removal of hydrogen sulfide.

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