A morphology-controllable sulfur-functionalized metal-organic framework catalytic material, a preparation method therefor and an application thereof
By using 2,5-thiophene dicarboxylic acid and bismuth nitrate pentahydrate to prepare sulfur-functionalized metal-organic frameworks (S-MOFs) with controllable morphology, the problem of insufficient performance of existing MOF photocatalysts was solved, achieving efficient degradation of organic pollutants and reduction of heavy metals, simplifying the preparation process and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-29
- Publication Date
- 2026-04-07
AI Technical Summary
Existing MOF photocatalysts have insufficient performance in degrading organic pollutants and reducing heavy metals. Their stability and catalytic activity need to be improved, and their preparation process is complex and costly.
Using 2,5-thiophene dicarboxylic acid as a ligand and bismuth nitrate pentahydrate as a metal source, morphology-controllable sulfur-functionalized metal-organic frameworks (S-MOFs) were prepared by ultrasonic synthesis. The ratio of metal to ligand was adjusted to improve catalytic activity and stability.
This method improves the efficiency of photocatalytic degradation of organic pollutants and ultrasound-photosynergistic reduction of hexavalent chromium, simplifies the preparation process, reduces costs, and enhances the environmental friendliness of the material.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of catalytic materials technology, specifically to a morphology-controllable sulfur-functionalized metal-organic framework catalytic material and its applications. Background Technology
[0002] Photocatalysis, as a green, environmentally friendly, and low-cost catalytic technology, is considered one of the most efficient and promising oxidation technologies for treating water pollutants in the 21st century due to its effective utilization of solar energy. Under light irradiation, photocatalysts undergo a photocatalytic reaction similar to photosynthesis on their surface, forming highly oxidizing free hydroxyl groups and reactive oxygen species (ROS). This results in strong photo-oxidation and reduction properties, effectively oxidizing or reducing various organic and inorganic compounds into harmless water molecules and carbon dioxide or lower-valence metal ions. Therefore, photocatalysis technology has been widely applied in wastewater treatment, formaldehyde adsorption, heavy metal reduction, carbon dioxide reduction, and water splitting for hydrogen production.
[0003] Metal-organic frameworks (MOFs) are coordination polymers formed by the coupling of inorganic metal clusters and organic ligands through coordination reactions. Traditional inorganic materials suffer from wide band gaps, easy recombination of photogenerated electron-hole pairs, and the susceptibility of some catalysts to corrosion and degradation. Therefore, MOFs have attracted much attention due to their unique properties, such as high surface area, tunable pore size and shape, and diverse functions. Ultrasonic MOFs (U-MOFs) are a subclass of MOFs explored for ultrasonic catalysis. Due to the presence of polar groups, asymmetric units, or structural distortions within their frameworks, they exhibit ultrasonic catalytic properties. U-MOFs also possess other advantages in ultrasonic catalysis, such as high porosity, large surface area, and abundant active sites. MOFs can have their porosity, specific surface area, and chemical properties altered by changing the types of metal clusters or ligands. In the field of photocatalysis, MOFs, as structurally tunable porous materials, have achieved some success. However, the performance and stability of currently prepared MOF photocatalysts in degrading organic pollutants do not yet meet the requirements of this technological field.
[0004] Therefore, providing a photocatalytic material with simple preparation method, high catalytic performance, good stability, low cost and environmental friendliness, and its preparation method is a problem that needs to be solved by those skilled in the art. Summary of the Invention
[0005] To address the problems of existing technologies, the present invention aims to propose a sulfur-functionalized metal-organic framework catalytic material with controllable morphology, its preparation method, and its application. This material features simple preparation, high catalytic performance, high stability, low cost, and environmental friendliness.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A sulfur-functionalized metal-organic framework catalytic material with controllable morphology, wherein the ligand of the catalytic material is 2,5-thiophene dicarboxylic acid and the metal source is bismuth salt;
[0008] The molar ratio of the ligand to the metal is 1:0.5-2.
[0009] Compared to the electron barriers formed by O and N atoms between the metal center and organic molecules, S atoms can lower the energy of the lowest unoccupied molecular orbital (LUMO) and increase the energy of the highest occupied molecular orbital (HOMO) of the ligands, thereby promoting photocatalytic activity by reducing the band gap. Simultaneously, the diffusion of lone pair electrons from S atoms can promote electron transfer, solving the problem of easy recombination of photogenerated electron-hole pairs, thus improving catalytic activity. Furthermore, MOF materials containing S exhibit photosensitivity, increasing the utilization efficiency of visible light.
[0010] Preferably, the bismuth salt is bismuth nitrate pentahydrate.
[0011] Preferably, the structure of the catalytic material is any one of micron-shaped flower spheres, spider webs, and micron-shaped flowers, and different morphologies of catalytic materials can be obtained by adjusting the ratio of the ligand to the metal.
[0012] Preferably, the molar ratio of the ligand to the metal is 1:0.5, which is a micron-sized flower-like structure; 1:1, which is a spider web-like structure; and 1:2, which is a micron-sized flower-like sphere-like structure.
[0013] The preparation method of the morphology-controllable sulfur-functionalized metal-organic framework catalytic material as described above includes the following specific steps:
[0014] Thiophene-2,5-dicarboxylic acid, bismuth salt, and polyvinylpyrrolidone are added to a solvent and mixed evenly. The mixture is then subjected to ultrasonic reaction, and the resulting product is a sulfur-functionalized metal-organic framework catalytic material with controllable morphology.
[0015] This invention utilizes thiophene-2,5-dicarboxylic acid as an S-atom-containing organic ligand and bismuth nitrate pentahydrate as a metal source to prepare a series of morphology-controllable sulfur-functionalized metal-organic frameworks (S-MOFs) through ultrasonic synthesis. These materials can effectively photocatalytically degrade organic pollutants and perform ultrasonic-photosynergistic catalytic reduction of hexavalent chromium.
[0016] Preferably, the mass ratio of the 2,5-thiophene dicarboxylic acid to the polyvinylpyrrolidone is 1-2:10;
[0017] The ultrasonic power is 600W, the reaction temperature is 60-80℃, and the time is 90min.
[0018] PVP acts as an organic carbon surfactant and pore size regulator, exhibiting a good effect in reducing reaction energy barriers. Other substances, such as CTAB (hexadecyltrimethylammonium bromide) and CTAC (hexadecyltrimethylammonium chloride), have anions such as Br and Cl that compete with the ligand thiophene-2,5-dicarboxylic acid for coordination, generating BiOBr or BiOCl impurities.
[0019] Preferably, the solvent is methanol and N,N-dimethylformamide in a volume ratio of 3:1.
[0020] A fixed solvent ratio helps to discover different morphologies caused by different metal and ligand ratios, and helps to control the morphology.
[0021] The above describes the application of a morphology-controllable sulfur-functionalized metal-organic framework catalytic material in the degradation of organic pollutants.
[0022] Preferably, the organic pollutant is Rhodamine B.
[0023] The above describes the application of a morphology-controllable sulfur-functionalized metal-organic framework catalytic material in the reduction of hexavalent chromium.
[0024] Preferably, the catalytic material employs ultrasonic-photocatalytic synergy in the reduction of hexavalent chromium.
[0025] Compared with the prior art, the present invention has the following beneficial effects:
[0026] Compared to most reported MOFs ultrasonic / photocatalysts, the ultrasonic / photocatalytic materials of a series of morphology-controllable sulfur-functionalized metal-organic frameworks (S-MOFs) prepared in this invention show significantly improved performance, while the preparation process is simple. Bismuth-based S-MOFs can increase the proportion of unsaturated metal active sites exposed on the material surface by different control of the metal-ligand ratio, thereby improving the redox activity of the metal center. In addition, S-MOFs are photosensitized, increasing the utilization efficiency of visible light. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings in this description are merely embodiments of the present invention.
[0028] Figure 1 The flowcharts are for the Bi-TDC prepared in Examples 1-3;
[0029] Figure 2 Scanning electron microscope images of the catalysts prepared in Examples 1-3;
[0030] Figure 3The graph shows the performance of the catalyst in photocatalytic degradation of RhB solution.
[0031] Figure 4 The performance diagram of the catalyst in catalytic reduction of hexavalent chromium in solvent and the UV-Vis absorption spectrum of the solvent are shown.
[0032] Figure 5 Here are the XRD and FT-IR plots of the BixTxUP. Detailed Implementation
[0033] Embodiments of the present invention are described below, examples of which are shown in the accompanying drawings. The embodiments described with reference to the drawings are exemplary and intended to explain the present invention, but are not to be construed as limiting the present invention.
[0034] Example 1
[0035] like Figure 1 A method for preparing a sulfur-functionalized metal-organic framework catalytic material with controllable morphology, specifically including the following steps:
[0036] A mixture of methanol and N,N-dimethylformamide in a volume ratio of 3:1 was used as a solvent. 2,5-thiophene dicarboxylic acid organic ligand, bismuth nitrate pentahydrate, and polyvinylpyrrolidone were added. The molar ratio of 2,5-thiophene dicarboxylic acid organic ligand to bismuth nitrate pentahydrate was 1:2, the mass ratio of 2,5-thiophene dicarboxylic acid to polyvinylpyrrolidone was 2:10, and the mass ratio of N,N-dimethylformamide to 2,5-thiophene dicarboxylic acid was 100:4. After stirring at room temperature for 30 min, the mixture was transferred to a 50 mL beaker and reacted at 60 °C for 90 min in a 600 W (40 kHz) ultrasonic cleaner. After the reaction was complete, the product was centrifuged and washed multiple times with N,N-dimethylformamide and methanol, respectively. The resulting product was then dried in a forced-air oven at 60 °C for 24 h to obtain a micron-sized flower-shaped (B1T2UP) sulfur-functionalized metal-organic framework (S-MOF) catalyst.
[0037] Example 2
[0038] like Figure 1 A method for preparing a sulfur-functionalized metal-organic framework catalytic material with controllable morphology, specifically including the following steps:
[0039] A mixture of methanol and N,N-dimethylformamide in a volume ratio of 3:1 was used as a catalyst. 2,5-thiophene dicarboxylic acid organic ligand, bismuth nitrate pentahydrate, and polyvinylpyrrolidone were added. The molar ratio of 2,5-thiophene dicarboxylic acid organic ligand to bismuth nitrate pentahydrate was 1:1, the mass ratio of 2,5-thiophene dicarboxylic acid to polyvinylpyrrolidone was 1:10, and the mass ratio of N,N-dimethylformamide to 2,5-thiophene dicarboxylic acid was 100:4. After stirring at room temperature for 30 min, the mixture was transferred to a 50 mL beaker and reacted at 60 °C for 90 min in a 600 W (40 kHz) ultrasonic cleaner. After the reaction was complete, the product was centrifuged and washed multiple times with N,N-dimethylformamide and methanol, respectively. The resulting product was then dried in a forced-air oven at 60 °C for 24 h to obtain a spiderweb-like (B1T1UP) sulfur-functionalized metal-organic framework (S-MOF) catalyst.
[0040] Example 3
[0041] like Figure 1 A method for preparing a sulfur-functionalized metal-organic framework catalytic material with controllable morphology, specifically including the following steps:
[0042] A mixture of methanol and N,N-dimethylformamide in a volume ratio of 3:1 was used as a catalyst. 2,5-thiophene dicarboxylic acid organic ligand, bismuth nitrate pentahydrate, and polyvinylpyrrolidone were added. The molar ratio of 2,5-thiophene dicarboxylic acid organic ligand to bismuth nitrate pentahydrate was 1:0.5, the mass ratio of 2,5-thiophene dicarboxylic acid to polyvinylpyrrolidone was 1:10, and the mass ratio of N,N-dimethylformamide to 2,5-thiophene dicarboxylic acid was 100:4. After stirring at room temperature for 30 min, the mixture was transferred to a 50 mL beaker and reacted at 60 °C for 90 min in a 600 W (40 kHz) ultrasonic cleaner. After the reaction was complete, the product was centrifuged and washed multiple times with N,N-dimethylformamide and methanol, respectively. The resulting product was then dried in a forced-air oven at 60 °C for 24 h to obtain a micron-shaped (B2T1UP) sulfur-functionalized metal-organic framework (S-MOF) catalyst.
[0043] Example 4
[0044] like Figure 1 A method for preparing a sulfur-functionalized metal-organic framework catalytic material with controllable morphology, specifically including the following steps:
[0045] A mixture of methanol and N,N-dimethylformamide (volume ratio 3:1) was prepared, and 2,5-thiophene dicarboxylic acid organic ligand, bismuth nitrate pentahydrate, and polyvinylpyrrolidone were added. The molar ratio of 2,5-thiophene dicarboxylic acid organic ligand to bismuth nitrate pentahydrate was 1:2, the mass ratio of 2,5-thiophene dicarboxylic acid to polyvinylpyrrolidone was 2:10, and the mass ratio of N,N-dimethylformamide to 2,5-thiophene dicarboxylic acid was 100:4. After stirring at room temperature for 30 min, the mixture was transferred to a 50 mL beaker and reacted at 70 °C for 90 min in a 600 W (40 kHz) ultrasonic cleaner. After the reaction was completed, the product was centrifuged and washed multiple times with N,N-dimethylformamide and methanol, respectively. The resulting product was then dried in a forced-air oven at 60 °C for 24 h to obtain a micron-sized flower-shaped (B1T2UP) sulfur-functionalized metal-organic framework (S-MOF) catalyst.
[0046] Example 5
[0047] like Figure 1 A method for preparing a sulfur-functionalized metal-organic framework catalytic material with controllable morphology, specifically including the following steps:
[0048] A mixture of methanol and N,N-dimethylformamide in a volume ratio of 3:1 was used as a catalyst. 2,5-thiophene dicarboxylic acid organic ligand, bismuth nitrate pentahydrate, and polyvinylpyrrolidone were added. The molar ratio of 2,5-thiophene dicarboxylic acid organic ligand to bismuth nitrate pentahydrate was 1:1, the mass ratio of 2,5-thiophene dicarboxylic acid to polyvinylpyrrolidone was 1:10, and the mass ratio of N,N-dimethylformamide to 2,5-thiophene dicarboxylic acid was 100:4. After stirring at room temperature for 30 min, the mixture was transferred to a 50 mL beaker and reacted at 70 °C for 90 min in a 600 W (40 kHz) ultrasonic cleaner. After the reaction was complete, the product was centrifuged and washed multiple times with N,N-dimethylformamide and methanol, respectively. The resulting product was then dried in a forced-air oven at 60 °C for 24 h to obtain a spiderweb-like (B1T1UP) sulfur-functionalized metal-organic framework (S-MOF) catalyst.
[0049] Example 6
[0050] like Figure 1 A method for preparing a sulfur-functionalized metal-organic framework catalytic material with controllable morphology, specifically including the following steps:
[0051] A mixture of methanol and N,N-dimethylformamide (volume ratio 3:1) was prepared, and 2,5-thiophene dicarboxylic acid organic ligand, bismuth nitrate pentahydrate, and polyvinylpyrrolidone were added. The molar ratio of 2,5-thiophene dicarboxylic acid organic ligand to bismuth nitrate pentahydrate was 1:0.5, the mass ratio of 2,5-thiophene dicarboxylic acid to polyvinylpyrrolidone was 1:10, and the mass ratio of N,N-dimethylformamide to 2,5-thiophene dicarboxylic acid was 100:4. After stirring at room temperature for 30 min, the mixture was transferred to a 50 mL beaker and reacted at 70 °C for 90 min in a 600 W (40 kHz) ultrasonic cleaner. After the reaction was completed, the product was centrifuged and washed multiple times with N,N-dimethylformamide and methanol, respectively. The resulting product was then dried in a forced-air oven at 60 °C for 24 h to obtain a micron-shaped (B2T1UP) sulfur-functionalized metal-organic framework (S-MOF) catalyst.
[0052] Example 7
[0053] like Figure 1 A method for preparing a sulfur-functionalized metal-organic framework catalytic material with controllable morphology, specifically including the following steps:
[0054] A mixture of methanol and N,N-dimethylformamide in a volume ratio of 3:1 was used as a solvent. 2,5-thiophene dicarboxylic acid organic ligand, bismuth nitrate pentahydrate, and polyvinylpyrrolidone were added. The molar ratio of 2,5-thiophene dicarboxylic acid organic ligand to bismuth nitrate pentahydrate was 1:2, the mass ratio of 2,5-thiophene dicarboxylic acid to polyvinylpyrrolidone was 2:10, and the mass ratio of N,N-dimethylformamide to 2,5-thiophene dicarboxylic acid was 100:4. After stirring at room temperature for 30 min, the mixture was transferred to a 50 mL beaker and reacted at 80 °C for 90 min in a 600 W (40 kHz) ultrasonic cleaner. After the reaction was complete, the product was centrifuged and washed multiple times with N,N-dimethylformamide and methanol, respectively. The resulting product was then dried in a forced-air oven at 60 °C for 24 h to obtain a micron-sized flower-shaped (B1T2UP) sulfur-functionalized metal-organic framework (S-MOF) catalyst.
[0055] Example 8
[0056] like Figure 1 A method for preparing a sulfur-functionalized metal-organic framework catalytic material with controllable morphology, specifically including the following steps:
[0057] A mixture of methanol and N,N-dimethylformamide in a volume ratio of 3:1 was used as a catalyst. 2,5-thiophene dicarboxylic acid organic ligand, bismuth nitrate pentahydrate, and polyvinylpyrrolidone were added. The molar ratio of 2,5-thiophene dicarboxylic acid organic ligand to bismuth nitrate pentahydrate was 1:1, the mass ratio of 2,5-thiophene dicarboxylic acid to polyvinylpyrrolidone was 1:10, and the mass ratio of N,N-dimethylformamide to 2,5-thiophene dicarboxylic acid was 100:4. After stirring at room temperature for 30 min, the mixture was transferred to a 50 mL beaker and reacted at 80 °C for 90 min in a 600 W (40 kHz) ultrasonic cleaner. After the reaction was complete, the product was centrifuged and washed multiple times with N,N-dimethylformamide and methanol, respectively. The resulting product was then dried in a forced-air oven at 60 °C for 24 h to obtain a micron-sized flower-shaped (B1T2UP) sulfur-functionalized metal-organic framework (S-MOF) catalyst.
[0058] Example 9
[0059] like Figure 1 A method for preparing a sulfur-functionalized metal-organic framework catalytic material with controllable morphology, specifically including the following steps:
[0060] A mixture of methanol and N,N-dimethylformamide in a volume ratio of 3:1 was used as a catalyst. 2,5-thiophene dicarboxylic acid organic ligand, bismuth nitrate pentahydrate, and polyvinylpyrrolidone were added. The molar ratio of 2,5-thiophene dicarboxylic acid organic ligand to bismuth nitrate pentahydrate was 1:0.5, the mass ratio of 2,5-thiophene dicarboxylic acid to polyvinylpyrrolidone was 1:10, and the mass ratio of N,N-dimethylformamide to 2,5-thiophene dicarboxylic acid was 100:4. After stirring at room temperature for 30 min, the mixture was transferred to a 50 mL beaker and reacted at 80 °C for 90 min in a 600 W (40 kHz) ultrasonic cleaner. After the reaction was complete, the product was centrifuged and washed multiple times with N,N-dimethylformamide and methanol, respectively. The resulting product was then dried in a forced-air oven at 60 °C for 24 h to obtain a micron-sized flower-shaped (B1T2UP) sulfur-functionalized metal-organic framework (S-MOF) catalyst.
[0061] Figure 2 The images show scanning electron microscope images of the Bi-TDC catalysts prepared in Examples 4-6, where (a) is B1T1UP, (b) is B1T2UP, and (c) is B2T1UP. As can be seen from the images, Bi-TDC exhibits a series of micron-shaped flower-like (B1T2UP), spider web-like (B1T1UP), and micron-shaped flower-like (B2T1UP) structures with controllable morphology.
[0062] Application Example 1
[0063] The catalyst prepared in Example 4 was used in the photocatalytic degradation of Rhodamine (RhB) experiment.
[0064] The specific experimental procedure was as follows: 10 mg of catalyst was added to 100 mL of 5 mg / L RhB dye. An adsorption-desorption reaction was first carried out under dark conditions for 40 min. After adsorption equilibrium was reached, a 300 W xenon lamp with a 420 nm filter was used for illumination. During the illumination process, 3 mL of dye solution was drawn every 10 min using a 5 mL syringe. The concentration of the RhB solution at different time intervals was measured using a UV-Vis spectrophotometer (554 nm). The results are shown in [Figure number missing]. Figure 3 ;
[0065] Figure 3 The graph shows the performance of photocatalytic degradation of RhB solution using sulfur-functionalized metal-organic frameworks in Example 1. (a) is the degradation concentration curve, (b) is the first-order reaction kinetics fitting curve, and (c) is a double bar graph of first-order reaction kinetic rate constant and degradation efficiency. As can be seen from the graph, RhB was fully degraded under light irradiation.
[0066] Application Example 2
[0067] The catalyst prepared in Example 4 was used to conduct a photocatalytic reduction experiment of hexavalent chromium Cr(VI).
[0068] The specific experimental procedure was as follows: 15 mg of catalyst was added to 100 mL of a 10 mg / L Cr(VI) solution. An adsorption-desorption reaction was first carried out under dark conditions for 40 min. After adsorption equilibrium was reached, a 300 W xenon lamp with a 420 nm filter was used to begin the photocatalytic experiment. During the experiment, 3 mL of solution was drawn every 10 min using a 5 mL syringe. The diphenylcarbazide method was used for colorimetric analysis. The concentration of Cr(VI) solution at different time intervals was measured using a UV-Vis spectrophotometer (540 nm). The results are shown in [Figure number missing]. Figure 4 (ad), where (a) is the degradation concentration curve, (b) is the first-order reaction kinetic fitting curve, (c) is the first-order reaction kinetic rate constant and degradation efficiency double bar chart, and (d) is the ultraviolet absorption spectrum.
[0069] Application Example 3
[0070] The catalyst prepared in Example 4 was subjected to an ultrasonic-photosynergistic reduction experiment of hexavalent chromium Cr(VI).
[0071] The specific experimental procedure was as follows: 15 mg of catalyst was added to 100 mL of a 10 mg / L Cr(VI) solution. An adsorption-desorption reaction was first carried out under dark conditions for 40 min. After adsorption equilibrium was reached, an ultrasonic catalytic experiment was conducted using a 300 W (40 kHz) ultrasonic cleaner. During the experiment, 3 mL of solution was drawn every 10 min using a 5 mL syringe. The diphenylcarbazide method was used for colorimetric analysis. The concentration of Cr(VI) solution at different time intervals was measured using a UV-Vis spectrophotometer (540 nm). The results are shown in [Figure number missing]. Figure 4 (eh);
[0072] Application Example 4
[0073] The catalyst prepared in Example 4 was subjected to an experiment involving the ultrasonic-photocatalytic reduction of hexavalent chromium Cr(VI).
[0074] The specific experimental procedure was as follows: 15 mg of catalyst was added to 100 mL of a 10 mg / L Cr(VI) solution. An adsorption-desorption reaction was first carried out under dark conditions for 40 min. After adsorption equilibrium was reached, an ultrasonic-photocatalytic experiment was conducted using a 300 W xenon lamp with a 420 nm filter and a 300 W (40 kHz) ultrasonic cleaner. During the experiment, 3 mL of solution was drawn every 10 min using a 5 mL syringe. The colorimetric method used was the diphenylcarbazide method. The concentration of Cr(VI) solution at different time intervals was measured using a UV-Vis spectrophotometer (540 nm). The results are shown in [Figure number missing]. Figure 4 (il);
[0075] Figure 4 The figures show the performance of the sulfur-functionalized metal-organic framework ultrasonic-photocatalyst for reducing hexavalent chromium in application examples 2-4, and the liquid UV absorption spectrum of B1T1UP. As can be seen from the figures, B1T1UP exhibits the best photocatalytic (50 min, 99.44%), ultrasonic catalytic (50 min, 77.36%), and ultrasonic-photocatalytic (10 min, 99.45%) activities in reducing hexavalent chromium. The high efficiency of photocatalysis can be attributed to the incorporation of sulfur, which gives B1T1UP photosensitivity. The high efficiency of ultrasonic catalysis can be attributed to the appropriate control of the metal-to-ligand ratio, which enables ultrasonic catalytic activity. The performance of the other two samples shows that neither excessive metal nor excessive ligand can achieve the performance of the B1T1UP sample. Therefore, for ultrasonically synthesized Bi-TDC, a 1:1 metal-to-ligand ratio is considered the optimal catalytic activity.
[0076] Figure 5 The infrared spectrum of sulfur-functionalized metal-organic frameworks, (a) 500-4000 cm⁻¹ -1(b) is 500-2000cm -1 (c) is the XRD pattern (2θ = 10⁻⁵⁰). The FT-IR spectrum shows the disappearance of the hydroxyl peak in thiophene-2,5-dicarboxylic acid and the shift of C=O to lower wavenumbers, which proves that Bi 3+ It underwent a coordination reaction with thiophene-2,5-dicarboxylic acid; the XRD pattern showed a different peak shape than that of the commonly hydrothermally synthesized Bi-TDC (CCDC:1545100), which can be attributed to the different chemical environment resulting from the different synthetic methods.
[0077] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A sulfur-functionalized metal-organic framework catalytic material with controllable morphology, characterized in that, The ligand of the catalytic material is 2,5-thiophene dicarboxylic acid, and the metal source is bismuth salt; The molar ratio of the ligand to the metal is 1:1; The preparation method of the catalytic material includes the following specific steps: Thiophene-2,5-dicarboxylic acid, bismuth salt and polyvinylpyrrolidone are added to a solvent and mixed evenly, and then subjected to ultrasonic reaction. The resulting product is a sulfur-functionalized metal-organic framework catalytic material with controllable morphology. The solvent is methanol and N,N-dimethylformamide in a volume ratio of 3:1; The mass ratio of the 2,5-thiophene dicarboxylic acid to the polyvinylpyrrolidone is 1-2:10; The ultrasonic power is 600W, the reaction temperature is 60-70℃, and the time is 90min; The catalytic material has a spiderweb-like structure.
2. The morphology-controllable sulfur-functionalized metal-organic framework catalytic material according to claim 1, characterized in that, The bismuth salt is bismuth nitrate pentahydrate.
3. The application of a morphology-controllable sulfur-functionalized metal-organic framework catalytic material as described in any one of claims 1-2 in the degradation of organic pollutants.
4. The application according to claim 3, characterized in that, The organic pollutant is Rhodamine B.
5. The application of a morphology-controllable sulfur-functionalized metal-organic framework catalytic material as described in any one of claims 1-2 in the reduction of hexavalent chromium.
6. The application according to claim 5, characterized in that, The catalytic material employs ultrasonic-photocatalytic synergy in the reduction of hexavalent chromium.