Bismuth-based metal-organic framework materials and methods of making the same
Patent Information
- Application Number
- CN202210709354.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-06-22
- Publication Date
- 2026-09-15
- Estimated Expiration
- 2042-06-22
AI Technical Summary
[0002]传统技术中制备铋基金属有机框架材料的主要途径是溶剂热法，且必须使用有机溶剂作为反应体系，溶剂热法虽然操作简便，但在制备过程存在周期长、能耗高等问题
[0017] The method for preparing bismuth-based metal-organic frameworks (MOFs) of this invention utilizes the lone pair electrons in cationic surfactants to preferentially replace hydrogen ions on the carboxyl groups of polybasic acid organic ligands in aqueous systems. This overcomes the problem of incomplete deprotonation of polybasic acid organic ligands, enabling the polybasic acid organic ligands to effectively bind with bismuth ions. This method is beneficial for preparing bismuth-based MOFs with good crystallinity, smaller size, and more uniform mass distribution. Furthermore, this preparation method has advantages such as low energy consumption and short cycle time, which is conducive to the large-scale production and application of bismuth-based MOFs.
Smart Images
Figure CN115181281B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic-inorganic hybrid materials technology, and in particular to a bismuth-based metal-organic framework material and its preparation method. Background Technology
[0002] The main traditional method for preparing bismuth-based metal-organic framework materials is the solvothermal method, which requires the use of organic solvents as the reaction system. Although the solvothermal method is simple to operate, it has problems such as long cycle and high energy consumption in the preparation process.
[0003] Although bismuth-based metal-organic frameworks (MOFs) can be prepared in aqueous systems through multi-step reactions, the conventionally prepared MOFs still have spatial structural defects, which reduces the yield of MOFs. Summary of the Invention
[0004] Therefore, it is necessary to provide a bismuth-based metal-organic framework material and its preparation method to address the above problems. The preparation method utilizes cationic surfactants to prepare bismuth-based metal-organic framework materials with good crystallinity, smaller size, and more uniform mass distribution in an aqueous system. Furthermore, the preparation method has advantages such as low energy consumption and short cycle time, which is conducive to the large-scale production and application of bismuth-based metal-organic framework materials.
[0005] A method for preparing a bismuth-based metal-organic framework material includes the following steps:
[0006] A mixture was prepared by mixing bismuth salt, a polybasic acid organic ligand, and a cationic surfactant; and
[0007] The mixture was mixed with water and subjected to ultrasonic treatment to obtain a bismuth-based metal-organic framework material.
[0008] In one embodiment, the mass ratio of the bismuth salt to the cationic surfactant is 30:1-2:10.
[0009] In one embodiment, the cationic surfactant is selected from at least one of haloalkyl quaternary ammonium salts and higher amine salts.
[0010] In one embodiment, the haloalkyl quaternary ammonium salt is selected from at least one of hexadecyltrimethylammonium bromide and dodecyltrimethylammonium bromide.
[0011] In one embodiment, the higher amine salt is selected from at least one of alkyl primary amine salts, alkyl secondary amine salts, and alkyl tertiary amine salts.
[0012] In one embodiment, the mass ratio of the bismuth salt to the polybasic acid organic ligand is 1:1 to 1:10, and the mass ratio of the bismuth salt to the water is 10:1 to 10:3.
[0013] In one embodiment, the bismuth salt is selected from at least one of bismuth nitrate pentahydrate, bismuth acetate, and bismuth oxynitrate.
[0014] In one embodiment, the polybasic acid organic ligand is selected from at least one of 1,3,5-pyromellitic acid, triazine-2,4,6-triyl-tribenzoic acid, and biphenyl-3,3′,5,5′-tetracarboxylic acid.
[0015] In one embodiment, the ultrasonic treatment time is 1 min to 90 min, and the ultrasonic treatment frequency is 30 kHz to 90 kHz.
[0016] A bismuth-based metal-organic framework material prepared by the method described above.
[0017] The method for preparing bismuth-based metal-organic frameworks (MOFs) of this invention utilizes the lone pair electrons in cationic surfactants to preferentially replace hydrogen ions on the carboxyl groups of polybasic acid organic ligands in aqueous systems. This overcomes the problem of incomplete deprotonation of polybasic acid organic ligands, enabling the polybasic acid organic ligands to effectively bind with bismuth ions. This method is beneficial for preparing bismuth-based MOFs with good crystallinity, smaller size, and more uniform mass distribution. Furthermore, this preparation method has advantages such as low energy consumption and short cycle time, which is conducive to the large-scale production and application of bismuth-based MOFs. Attached Figure Description
[0018] Figure 1 This is a scanning electron microscope image of the bismuth-based metal-organic framework material prepared in Example 1;
[0019] Figure 2 The X-ray diffraction pattern of the bismuth-based metal-organic framework material prepared in Example 1 is shown below.
[0020] Figure 3 Scanning electron microscope (SEM) images of the products prepared in Comparative Examples 1, 2, and 3.
[0021] Figure 4 The X-ray diffraction patterns are of the products prepared in Comparative Examples 1, 2 and 3. Detailed Implementation
[0022] To facilitate understanding of the present invention, it will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. Rather, these embodiments or examples are provided to make the disclosure of the present invention more thorough and complete.
[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments or examples only and is not intended to be limiting of the invention.
[0024] Through long-term and in-depth research, the applicant discovered that in the synthesis of metal-organic frameworks (MOFs), organic ligands dissolved in solvent systems need to be deprotonated to facilitate bonding with metal ions and thus form a complete MOF framework. However, in aqueous systems, the deprotonation of polybasic acid organic ligands is incomplete, resulting in bismuth ions reacting only with partially deprotonated carboxyl groups, thus generating intermediates. In aqueous systems, these intermediates are difficult to grow completely to form a complete MOF framework.
[0025] Based on this, the present invention provides a method for preparing a bismuth-based metal-organic framework material, comprising the following steps:
[0026] S1, bismuth salt, polybasic acid organic ligand, and cationic surfactant are mixed to obtain a mixture; and
[0027] S2, the mixture is mixed with water and subjected to ultrasonic treatment to obtain a bismuth-based metal-organic framework material.
[0028] In step S1, since the cationic surfactant can effectively bind to the organic ligand of the polybasic acid, it is beneficial to improve the complete deprotonation of the organic ligand of the polybasic acid.
[0029] To ensure complete deprotonation of the polybasic acid organic ligand, the mass ratio of the bismuth salt to the cationic surfactant is 30:1-2:10, preferably 20:1-2:10, wherein the cationic surfactant is selected from at least one of haloalkyl quaternary ammonium salts and higher amine salts.
[0030] Specifically, the haloalkyl quaternary ammonium salt is selected from at least one of hexadecyltrimethylammonium bromide and dodecyltrimethylammonium bromide; the higher amine salt is selected from at least one of alkyl primary amine salt, alkyl secondary amine salt, and alkyl tertiary amine salt, wherein the alkyl primary amine salt is selected from dodecylamine hydrochloride, the alkyl secondary amine salt is selected from bis(octadecylamine) hydrochloride, and the alkyl tertiary amine salt is selected from N,N-dimethyloctadecylamine hydrochloride.
[0031] Since cationic surfactants can form micelles in solution, they can enrich bismuth ions and polybasic acid organic ligands, thereby promoting the synthesis of bismuth-based metal-organic framework materials. The cationic surfactant is preferably a haloalkyl quaternary ammonium salt, and more preferably hexadecyltrimethylammonium bromide.
[0032] To ensure the formation of bismuth-based metal-organic framework materials, the mass ratio of the bismuth salt to the polybasic acid organic ligand is controlled to be 1:1-1:10. Furthermore, to improve the product conversion rate, the mass ratio of the bismuth salt to the polybasic acid organic ligand is preferably 1:1-1:5.
[0033] Specifically, the bismuth salt is selected from at least one of bismuth nitrate pentahydrate, bismuth acetate, and bismuth oxynitrate, preferably bismuth nitrate pentahydrate; the polybasic acid organic ligand is selected from at least one of 1,3,5-pyromellitic acid, triazine-2,4,6-triyl-tribenzoic acid, and biphenyl-3,3′,5,5′-tetracarboxylic acid, preferably 1,3,5-pyromellitic acid.
[0034] Furthermore, the 1,3,5-pyromellitic acid can react with the bismuth salt to form CAU-7 and CAU-17, the triazine-2,4,6-triyl-tribenzoic acid can react with the bismuth salt to form CAU-35, and the biphenyl-3,3′,5,5′-tetracarboxylic acid can react with the bismuth salt to form NOTT-220. CAU-7, CAU-17, CAU-35, and NOTT-220 are bismuth-based metal-organic framework materials with different topological structures.
[0035] In step S2, in an aqueous solution at room temperature and pressure, the lone pair electrons contained in the cationic surfactant are used to enable the cationic surfactant to preferentially replace the hydrogen ions on the carboxyl groups on the surface of the polybasic acid organic ligand in the aqueous system. This overcomes the problem of incomplete deprotonation of the polybasic acid organic ligand and is beneficial to promoting the efficient bonding of the deprotonated polybasic acid organic ligand with bismuth ions.
[0036] To improve the product conversion rate, the mass ratio of the bismuth salt to the water is 10:1-10:3, preferably 20:3-5:1.
[0037] To further reduce the impact of micro-ions in the water on the reaction process, the water is preferably deionized water.
[0038] Because the water system contains a certain proportion of bismuth salt, polybasic acid organic ligands and cationic surfactants, when ultrasonic treatment is performed under certain ultrasonic frequency conditions, the cationic surfactant preferentially replaces the hydrogen ions on the carboxyl groups on the surface of the polybasic acid organic ligands, so that the polybasic acid organic ligands are completely deprotonated, which is conducive to the bonding of bismuth ions with the deprotonated polybasic acid organic ligands.
[0039] Meanwhile, due to the effect of ultrasonic treatment, bismuth ions and deprotonated polybasic acid organic ligands undergo intense intermolecular vibrations, which promote the generation of tiny gaps inside the molecules. These tiny gaps expand and close rapidly with the ultrasonic frequency, causing intense collisions between molecules. This further enhances the bonding between bismuth ions and deprotonated polybasic acid organic ligands, and efficiently promotes the crystal growth of bismuth-based organometallic frameworks. As a result, bismuth-based metal-organic framework materials have good crystallinity, smaller size, and more uniform mass distribution.
[0040] In some embodiments, the ultrasonic treatment time is 1 min to 90 min, and the ultrasonic treatment frequency is 30 kHz to 90 kHz; further, in order to reduce energy loss, improve preparation efficiency and shorten the preparation cycle, the ultrasonic treatment time is preferably 30 min to 60 min; and the ultrasonic treatment frequency is preferably 35 kHz to 50 kHz.
[0041] Therefore, this invention utilizes cationic surfactants to prepare bismuth-based metal-organic framework materials with good crystallinity, smaller size, and more uniform mass distribution in an aqueous system. Furthermore, this preparation method has advantages such as low energy consumption, short cycle time, mild and safe preparation process, and no pollution, which is conducive to the large-scale production and application of bismuth-based metal-organic framework materials.
[0042] In addition, the bismuth-based metal-organic framework material prepared by this invention has unique three-dimensional porous structural units, high specific surface area and high structural stability, and the pore size can be controlled. It can be widely used in carbon dioxide adsorption and reduction, adsorption of pollutants in water, and as a precursor for the preparation of BiVO4 materials with photocatalytic activity.
[0043] The present invention also provides a bismuth-based metal-organic framework material obtained by the above preparation method.
[0044] Compared with bismuth-based metal-organic frameworks prepared by traditional hydrothermal methods and multi-step methods in aqueous systems, the bismuth-based metal-organic frameworks prepared by the method provided in this invention have smaller and more uniform sizes.
[0045] Specifically, the bismuth-based metal-organic framework material is in the form of a short rod, and the length of the bismuth-based metal-organic framework material is 200 nm-2 μm, preferably 800 nm-1.5 μm.
[0046] The preparation method of the bismuth-based metal-organic framework material will be further described below through specific embodiments.
[0047] In the embodiments, the accelerating voltage during the scanning electron microscope (Zeiss vltra55) test was 0.5kV-30kV, and the magnification was 100,000-500,000 times.
[0048] In this embodiment, the X-ray powder diffractometer (Bruker D8) was used for testing under the conditions of 40mA scanning current and 40kV scanning voltage. The light source of the X-ray powder diffractometer was Cu-Kal, and the test angle was 5°-50°.
[0049] Example 1
[0050] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid, and 5 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 37 kHz for 40 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0051] Figure 1 Scanning electron microscope images of the fabricated bismuth-based metal-organic framework material, from Figure 1 It is known that the bismuth-based metal-organic framework material is in the shape of a short rod, with a length of 800 nm to 1.5 μm, and the size distribution is uniform.
[0052] Figure 2 The X-ray diffraction pattern of the prepared bismuth-based metal-organic framework material is shown in the figure. Figure 2 It is known that the bismuth-based metal-organic framework material has good crystallinity and exhibits the unique layered diffraction peaks of bismuth-based metal-organic framework materials in the diffraction angle range of 5°-50°. Furthermore, the positions of all diffraction peaks of the bismuth-based metal-organic framework material correspond one-to-one with the positions of diffraction peaks of the known CAU-17 crystal structure, indicating that the bismuth-based metal-organic framework material has the same crystal structure as CAU-17, that is, the bismuth-based metal-organic framework material is CAU-17.
[0053] Example 2
[0054] 100 mg of bismuth nitrate pentahydrate, 100 mg of 1,3,5-pyromellitic acid, and 5 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 37 kHz for 40 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0055] Example 3
[0056] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid, and 50 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 37 kHz for 40 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0057] Example 4
[0058] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid, and 100 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 37 kHz for 40 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0059] Example 5
[0060] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid, and 5 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at a working frequency of 50 kHz for 40 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0061] Example 6
[0062] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid, and 5 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 90 kHz for 40 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0063] Example 7
[0064] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid, and 5 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 37 kHz for 20 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0065] Example 8
[0066] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid, and 5 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 37 kHz for 90 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0067] Example 9
[0068] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid, and 5 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 30 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 37 kHz for 40 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0069] Example 10
[0070] 100 mg of bismuth acetate, 500 mg of 1,3,5-pyromellitic acid, and 5 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 37 kHz for 40 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0071] Example 11
[0072] 100 mg of bismuth nitrate pentahydrate, 500 mg of triazine-2,4,6-triyl-tribenzoic acid, and 5 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 37 kHz for 40 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0073] Example 12
[0074] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid, and 5 mg of dodecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 37 kHz for 40 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0075] Example 13
[0076] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid, and 5 mg of dioctadecylamine hydrochloride were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 15 mL of deionized water was added. The mixture was ultrasonically oscillated at an ultrasonic working frequency of 37 kHz for 40 min. The final product was transferred to a large beaker, deionized water was added, and the mixture was centrifuged and washed three times to obtain the bismuth-based metal-organic framework material.
[0077] Comparative Example 1
[0078] 100 mg of bismuth nitrate pentahydrate and 500 mg of 1,3,5-pyromellitic acid were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 20 mL of deionized water was added. The mixture was ultrasonically oscillated at a working frequency of 37 kHz for 40 min. After ultrasonic oscillation, a product was generated in the mixed solution. The product was washed three times with deionized water by centrifugation.
[0079] Figure 3 Including scanning electron microscope images of the obtained product, from Figure 3 (a) It can be seen that the product is in the form of micron-sized flakes, and the size distribution is uneven.
[0080] Figure 4 The X-ray diffraction pattern of the obtained product is included. Figure 4(a) It can be seen that the position of the diffraction peak of the product is different from the position of the diffraction peak of the known CAU-17 crystal structure, indicating that the product is not CAU-17.
[0081] Comparative Example 2
[0082] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid and 5 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. Then, 20 mL of deionized water was added and the container was left to stand at room temperature for 40 min. A product was generated in the mixed solution. The product was washed three times by centrifugation with deionized water.
[0083] Figure 3 Including scanning electron microscope images of the obtained product, from Figure 3 (b) It is known that the product is in the form of aggregated fragments, which are mixed with some fragments.
[0084] Figure 4 The X-ray diffraction pattern of the obtained product is included. Figure 4 (b) It can be seen that the position of the diffraction peak of the product is different from the position of the diffraction peak of the known CAU-17 crystal structure, indicating that the product is not CAU-17.
[0085] Comparative Example 3
[0086] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid and 5 mg of hexadecyltrimethylammonium bromide were mixed and stirred until homogeneous to obtain a mixture. Then, 20 mL of deionized water was added and the container was placed on a stirring table and stirred at room temperature for 40 min. A product was generated in the mixed solution. The product was washed three times by centrifugation with deionized water.
[0087] Figure 3 Including scanning electron microscope images of the obtained product, from Figure 3 (c) It can be seen that the product is in the form of micron-sized blocks with fragments distributed on its surface.
[0088] Figure 4 The X-ray diffraction pattern of the obtained product is included. Figure 4 (c) It can be seen that the position of the diffraction peak of the product is different from the position of the diffraction peak of the known CAU-17 crystal structure, indicating that the product is not CAU-17.
[0089] Comparative Example 4
[0090] 100 mg of bismuth nitrate pentahydrate, 500 mg of 1,3,5-pyromellitic acid, and 5 mg of sodium dodecyl sulfate were mixed and stirred until homogeneous to obtain a mixture. The container containing the mixture sample was placed in an ultrasonic oscillator, and then 20 mL of deionized water was added. The mixture was ultrasonically oscillated at a frequency of 37 kHz for 40 min. After ultrasonic oscillation, no product was formed in the mixed solution.
[0091] As can be seen from Examples 1-13 and Comparative Example 1, bismuth-based metal-organic framework materials cannot be prepared by simply placing bismuth salts and polybasic acid organic ligands into a dehydration reaction system without adding cationic surfactants and only performing ultrasonic oscillation reactions.
[0092] As can be seen from Examples 1-13 and Comparative Examples 2 and 3, bismuth-based metal-organic framework materials cannot be prepared by placing bismuth salts, polybasic acid organic ligands and cationic surfactants into an aqueous reaction system without ultrasonic vibration reaction.
[0093] As can be seen from Examples 1-13 and Comparative Example 4, no product is generated when sodium dodecyl sulfate is reacted with bismuth salt and polybasic acid organic ligands in an aqueous reaction system using ultrasonic oscillation.
[0094] In summary, in the preparation method of bismuth-based metal-organic framework materials proposed in this invention, cationic surfactants and ultrasonic treatment are necessary technical conditions for the preparation of bismuth-based metal-organic framework materials. Only when cationic surfactants are used in conjunction with ultrasonic treatment can bismuth-based metal-organic framework materials with good crystallinity, smaller size, and more uniform mass distribution be prepared.
[0095] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0096] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A method for preparing a bismuth-based metal-organic framework material, characterized in that, Includes the following steps: Bismuth nitrate pentahydrate, 1,3,5-pyromellitic acid, and hexadecyltrimethylammonium bromide were mixed to obtain a mixture, wherein the mass ratio of bismuth nitrate pentahydrate to hexadecyltrimethylammonium bromide was 20:1-2:1; and The mixture was mixed with water and subjected to ultrasonic treatment to obtain a bismuth-based metal-organic framework material.
2. The method for preparing bismuth-based metal-organic framework materials according to claim 1, characterized in that, The mass ratio of bismuth nitrate pentahydrate to 1,3,5-pyromellitic acid is 1:1 to 1:10, and the mass ratio of bismuth nitrate pentahydrate to water is 10:1 to 10:
3.
3. The method for preparing bismuth-based metal-organic framework materials according to claim 1, characterized in that, The ultrasonic treatment time is 1 min to 90 min, and the ultrasonic treatment frequency is 30 kHz to 90 kHz.
4. A bismuth-based metal-organic framework material prepared by the method for preparing bismuth-based metal-organic framework materials according to any one of claims 1-3.