MOFs material, preparation method thereof and application of MOFs material to adsorption and detection of PFOS
By preparing Ce-MOF materials rich in amino functional groups and Ce3+ active sites, highly sensitive detection and efficient removal of PFOS were achieved, solving the problem of PFOS detection and removal in existing technologies, and making them suitable for environmental pollution control and human health protection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- KUNMING UNIV OF SCI & TECH
- Filing Date
- 2026-03-13
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies are insufficient for the economical and rapid detection and removal of perfluorooctane sulfonic acid (PFOS), especially in field environments. Furthermore, traditional methods are costly and require specialized operation, making rapid screening and timely treatment difficult.
Metal-organic framework compounds (Ce-MOFs) rich in amino functional groups and Ce3+ active sites were prepared, and high-sensitivity detection was achieved through fluorescence quenching effect, while PFOS was removed through selective adsorption.
It achieves visualized and highly sensitive detection of PFOS, with a detection limit of 16 ppb and an adsorption capacity of 724.6 mg/g. The detection results are highly accurate, the operation is simple, and it is suitable for rapid on-site detection and purification.
Smart Images
Figure CN122011419A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of functional materials technology, and relates to a MOF material, its preparation method, and its application in PFOS adsorption and detection. Background Technology
[0002] Metal-organic frameworks (MOFs) are a class of crystalline porous materials with a periodic network structure, formed by the self-assembly of inorganic metal centers (metal ions or metal clusters) and bridging organic ligands. MOFs are organic-inorganic hybrid materials, also known as coordination polymers. They differ from both inorganic porous materials and typical organic complexes, possessing both the rigidity of inorganic materials and the flexibility of organic materials, thus demonstrating enormous potential in modern materials research.
[0003] Perfluorooctane sulfonic acid (PFOS), a typical long-chain perfluoroalkyl acid, is the most abundant polyfluoroalkyl substance (PFAS) in the environment. PFOS is characterized by high mobility, high persistence, and high potential toxicity, making it a prevalent environmental pollutant. Currently, PFOS detection mainly relies on techniques such as liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). While these methods offer high accuracy, the instruments are expensive, and the operations require specialized knowledge, typically limiting them to laboratory settings and hindering rapid on-site screening and timely treatment. Therefore, economical and rapid detection and removal of PFOS is crucial for environmental pollution control and human health protection.
[0004] Therefore, it is necessary to provide a metal-organic framework compound material, its preparation method, and its application to achieve economical and rapid detection and removal of perfluorooctane sulfonic acid. Summary of the Invention
[0005] To overcome the problems in the prior art, the present invention prepares a product rich in amino functional groups and Ce. 3+ Metal-organic framework materials with active sites (Ce-MOF) generate fluorescence and fluorescence quenching effect through the interaction between Ce-MOF and PFOS, enabling visualized, highly sensitive, and selective detection of PFOS. At the same time, PFOS can be effectively removed by selectively adsorbing PFOS in a large capacity.
[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: In one aspect, this invention proposes a MOF (Metal-Oxide-Factory) material, wherein the organic ligand of the MOF material is 2-aminoterephthalic acid and the inorganic metal center is Ce. 3+ .
[0007] In another aspect, this invention provides a method for preparing the above-mentioned MOFs material, the method comprising the following steps: (1) 2-Aminoterephthalic acid and Ce(NO3)3·6H2O were added to N,N-dimethylformamide (DMF) in sequence and ultrasonically treated to fully dissolve 2-aminoterephthalic acid and Ce(NO3)3·6H2O in N,N-dimethylformamide to obtain a reaction solution.
[0008] (2) The reaction solution is subjected to a solvothermal reaction.
[0009] (3) The reaction products were centrifuged and washed in sequence, then soaked in methanol and dried to obtain MOFs materials.
[0010] Preferably, in step (1), the molar ratio of 2-aminoterephthalic acid to Ce(NO3)3·6H2O is 2-aminoterephthalic acid:Ce(NO3)3·6H2O=5:1.
[0011] In step (1), DMF is used only as a solvent to provide the reaction environment. The amount used is sufficient to completely dissolve 2-aminoterephthalic acid and Ce(NO3)3·6H2O. It can be used in excess. Excess DMF will not affect the performance of the final product or the reaction process.
[0012] Preferably, in step (2), the temperature of the solvothermal reaction is 110-130℃ and the reaction time is 22-26h.
[0013] Preferably, in step (1), the ultrasonic frequency is 55-65Hz.
[0014] Preferably, in step (3), the centrifugation speed is 4000-5000 rpm and the centrifugation time is 4-5 min.
[0015] Preferably, in step (3), the solid product obtained after centrifugation is washed three times with DMF and then washed three times with methanol.
[0016] Preferably, in step (3), after soaking in methanol for 22-26 hours, fresh methanol is used to soak the product for another 22-26 hours before drying.
[0017] Preferably, in step (3), the drying temperature is 55-65℃ and the drying time is 12-16h.
[0018] The beneficial effects of this invention are: 1. The metal-organic framework compound material of the present invention has excellent optical properties, and the luminescence is driven by the intramolecular charge transfer process dominated by ligands. It has high selectivity for PFOS, strong resistance to interference from other substances and PFAS, and can achieve visual and high-sensitivity detection of PFOS with a detection limit of 16 ppb.
[0019] 2. The metal-organic framework compound material of the present invention has the same high selective adsorption performance for PFOS, thus it can effectively remove PFOS, and the adsorption capacity can reach 724.6 mg / g.
[0020] 3. The detection results of this invention have high accuracy, precision, and stability, with a recovery rate of 95.31%-101.4% and an RSD of no more than 4.1%.
[0021] 4. The metal-organic framework compound material detection process of this invention is simple to operate and requires little professional expertise. It can fully meet the needs of on-site economic, rapid, and high-precision detection of PFOS and timely purification of PFOS, making it suitable for industrial promotion and application. Attached Figure Description
[0022] Figure 1 This is a SEM image of the Ce-MOF of the present invention; Figure 2 This is the Fourier transform infrared image of the Ce-MOF of this invention; Figure 3 This is a fluorescence effect diagram of Ce-MOF visualization for PFOS detection in this invention; Figure 4 This is a linear relationship between the fluorescence effect of Ce-MOF in this invention and the PFOS content; Figure 5 This is a graph showing the adsorption kinetics of Ce-MOF for PFOS according to the present invention. Figure 6 The diagram shows the pseudo-second-order kinetic fitting and thermodynamic analysis of Ce-MOF adsorption of PFOS based on a first-order model in this invention. Figure 7 This is a Langmuir model fitting diagram of Ce-MOF adsorption of PFOS according to the present invention. Detailed Implementation
[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the content described.
[0024] Example 1 This embodiment prepares Ce-MOF through the following steps: (1) Weigh 0.45g of 2-aminoterephthalic acid and dissolve it in 30mL of DMF. Then add 0.22g of Ce(NO3)3·6H2O. Under normal temperature conditions, sonicate at a frequency of 60Hz for 15min. 2-aminoterephthalic acid and Ce(NO3)3·6H2O are completely dissolved in DMF to obtain the reaction solution.
[0025] (2) The reaction solution was transferred to a 50 mL polytetrafluoroethylene-lined autoclave and reacted at 120 °C for 24 h. The reaction was completed and the reaction product was obtained.
[0026] (3) After the autoclave cools down, take out the reaction product and centrifuge the reaction product at 4000 rpm for 5 min. Collect the solid product and wash it three times each with DMF and methanol. Then soak the solid product in methanol for 48 h. Replace with fresh methanol after soaking for 24 h and continue soaking for 24 h. Finally, place the solid product in a vacuum oven and dry it at 60 °C for 12 h to obtain Ce-MOF.
[0027] Scanning electron microscopy (SEM) experiments were performed on the Ce-MOF prepared in Example 1, and the results are as follows: Figure 1 As shown.
[0028] pass Figure 1 It can be seen that Ce-MOF has a spherical crystal structure, and carbon, nitrogen, oxygen and cerium elements are distributed in the Ce-MOF structure.
[0029] Ce-MOF was detected using Fourier transform infrared spectroscopy, and the results are as follows: Figure 2 As shown.
[0030] pass Figure 2 It can be seen that in Ce-MOF, the ligands have been deprotonated and coordinate with Ce ions in the form of carboxylate groups.
[0031] Example 1 This example demonstrates the performance of Ce-MOF visualization in detecting PFOS using the following methods: (1) Disperse the dried Ce-MOF powder in ultrapure water to achieve a final concentration of 500 ug / mL.
[0032] (2) Prepare 15 Ce-MOF solutions and add different amounts of PFOS to the Ce-MOF solutions respectively, so that the PFOS concentration in the Ce-MOF solutions is different, namely 0.1, 0.2, 0.3, 0.4, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 and 5 ppm. One Ce-MOF solution is not added with PFOS. After adding PFOS, adjust the pH of all Ce-MOF solutions to neutral and then incubate at 25°C for 10 min.
[0033] The fluorescence spectrum of the Ce-MOF was measured using a fluorescence spectrometer under the conditions of excitation wavelength 330 nm and emission wavelength 350–550 nm, as shown in the figure. Figure 3 As shown.
[0034] pass Figure 3 As can be seen, the emission intensity at 426 nm gradually decreases as the PFOS concentration increases from 0 to 5 ppm, confirming that the Ce-MOF of this invention interacts with PFOS to produce fluorescence, and that Ce-MOF can serve as a fluorescent probe for PFOS in solution.
[0035] pass Figure 4 It can be seen that PFOS concentration and Ce-MOF fluorescence effect show a linear relationship. Within the PFOS concentration range of 0-1 ppm, lg(F / F0) shows an inverse linear relationship with PFOS concentration, indicating a good linear correlation. The fitted linear regression equation is lg(F / F0) = -0.00329 - 0.09272 × C, where F is the actual fluorescence emission intensity after adding PFOS, F0 is the fluorescence emission intensity of the Ce-MOF solution without PFOS, and C is the PFOS concentration. The correlation coefficient is 0.9955.
[0036] The limit of detection (LOD) of Ce-MOF is calculated using the formula LOD = 3Sb / K, where Sb represents the standard deviation of the blank measurement and K is the slope of the linear fit. The calculated LOD is 16 ppb.
[0037] pass Figure 4 It can also be seen that in the range of PFOS concentration from 1 ppm to 5 ppm, the PFOS concentration and Ce-MOF fluorescence intensity satisfy the linear regression fitting equation lg(F / F0) = -0.0872 - 0.0388 × C, with a correlation coefficient of 0.9597.
[0038] Example 2 This example demonstrates the performance of Ce-MOF in removing PFOS through the following methods: (1) Mix 20 mg Ce-MOF with 32 mL of deionized water and sonicate for 5 min to make Ce-MOF uniformly dispersed in deionized water to prepare adsorbent mother liquor.
[0039] (2) Add 8 mL of PFOS standard solution with a concentration of 1 mg / L to the adsorbent mother liquor to obtain the experimental liquid.
[0040] The experimental liquid was stirred at 25℃, and samples were taken at 0, 1, 5, 10, 15, 30, 60, and 180 min, respectively. Each sample was 1 mL, filtered through a 0.22 μm filter membrane, and the PFOS concentration was determined by HPLC. The results are shown below. Figure 5 As shown.
[0041] pass Figure 5 It can be seen that Ce-MOF adsorbs PFOS very rapidly in the initial stage, reaching more than 90% of the adsorption equilibrium within 60 minutes. This indicates that PFOS molecules can quickly diffuse into the pores of Ce-MOF and bind to the active sites, proving that Ce-MOF has a highly efficient selective removal performance for PFOS.
[0042] Seven identical adsorption stock solutions were prepared. Eight mL of PFOS standard solutions with concentrations of 1, 10, 20, 50, 100, 200, and 400 mg / L were added to each stock solution. The solutions were stirred at 25°C for 2 hours until equilibrium was reached. One mL samples were taken from each of the seven solutions, filtered through a 0.22 μm filter, and the PFOS concentration was measured. Adsorption isotherm tests were performed, and the results are shown below. Figure 6 , 7 As shown.
[0043] pass Figure 6 It can be seen that the adsorption kinetics of Ce-MOF for PFOS conforms to the pseudo-second-order model (R0). 2 =0.9954), indicating that the adsorption of PFOS by Ce-MOF is likely mainly chemisorption.
[0044] pass Figure 7 It can be seen that there are homogeneous monolayer adsorption sites on the Ce-MOF surface, and the maximum theoretical adsorption capacity of Ce-MOF for PFOS can be measured to be 724.6 mg / g.
[0045] Example 2 This embodiment prepares Ce-MOF through the following steps: (1) Weigh 0.45g of 2-aminoterephthalic acid and dissolve it in 30mL of DMF. Then add 0.22g of Ce(NO3)3·6H2O. Under normal temperature conditions, sonicate at a frequency of 55Hz for 15min. 2-aminoterephthalic acid and Ce(NO3)3·6H2O are completely dissolved in DMF to obtain the reaction solution.
[0046] (2) The reaction solution was transferred to a 50 mL high-pressure reactor lined with polytetrafluoroethylene and reacted at 110 °C for 26 h. The reaction was completed and the reaction product was obtained.
[0047] (3) After the autoclave cools down, take out the reaction product and centrifuge the reaction product at 5000 rpm for 4 min. Collect the solid product and wash the solid product three times each with DMF and methanol. Then soak the solid product in methanol for 22 h. After soaking for 22 h, replace with fresh methanol and continue soaking for 22 h. Finally, place the solid product in a vacuum oven and dry at 55 °C for 16 h to obtain Ce-MOF.
[0048] The Ce-MOF prepared in this embodiment has similar performance to that of Example 1.
[0049] Example 3 This embodiment prepares Ce-MOF through the following steps: (1) Weigh 0.45g of 2-aminoterephthalic acid and dissolve it in 30mL of DMF. Then add 0.22g of Ce(NO3)3·6H2O. Under normal temperature conditions, sonicate at a frequency of 65Hz for 15min. 2-aminoterephthalic acid and Ce(NO3)3·6H2O are completely dissolved in DMF to obtain the reaction solution.
[0050] (2) The reaction solution was transferred to a 50 mL high-pressure reactor lined with polytetrafluoroethylene and reacted at 130 °C for 22 h. The reaction was completed and the reaction product was obtained.
[0051] (3) After the autoclave cools down, take out the reaction product and centrifuge the reaction product at 4500 rpm for 4.5 min. Collect the solid product and wash it three times each with DMF and methanol. Then soak the solid product in methanol for 26 h. After soaking for 26 h, replace it with fresh methanol and continue soaking for 26 h. Finally, place the solid product in a vacuum oven and dry it at 65 °C for 14 h to obtain Ce-MOF.
[0052] The Ce-MOF prepared in this embodiment has similar performance to that of Example 1.
[0053] In summary, this invention successfully prepared a product rich in amino functional groups and Ce. 3+Metal-organic framework materials with active sites enable the visualization, high sensitivity, and high accuracy detection of PFOS, with high reliability and good detection stability. They can also achieve highly selective adsorption and removal of PFOS, which is of great significance for environmental pollution control.
[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.
Claims
1. A MOFs material, characterized in that: The organic ligand of the MOF material is 2-aminoterephthalic acid, and the inorganic metal center is Ce. 3+ .
2. The method for preparing MOFs material according to claim 1, characterized in that: The preparation method includes the following steps: (1) 2-aminoterephthalic acid and Ce(NO3)3·6H2O were added to N,N-dimethylformamide in sequence and ultrasonically treated to fully dissolve 2-aminoterephthalic acid and Ce(NO3)3·6H2O in N,N-dimethylformamide to obtain a reaction solution; (2) The reaction solution is subjected to a solvothermal reaction; (3) The reaction products were centrifuged and washed in sequence, then soaked in methanol and dried under vacuum to obtain MOFs materials.
3. The preparation method according to claim 2, characterized in that: In step (1), the molar ratio of 2-aminoterephthalic acid to Ce(NO3)3·6H2O is 5:
1.
4. The preparation method according to claim 2, characterized in that: In step (2), the temperature of the solvothermal reaction is 110-130℃ and the reaction time is 22-26h.
5. The application of the metal-organic framework compound material of claim 1 in the visual detection of perfluorooctane sulfonic acid.
6. The application of the metal-organic framework chemical material of claim 1 in the removal of perfluorooctane sulfonic acid contaminants.