A carbon dot-functionalized lanthanide metal-organic framework material that can be detected by permanganate ion in water.
By preparing carbon dot-functionalized lanthanide metal-organic framework materials, the problem of complex and time-consuming existing methods for permanganate ion detection has been solved, and rapid and accurate permanganate ion detection with high sensitivity and anti-interference ability has been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SICHUAN NORMAL UNIV
- Filing Date
- 2026-05-14
- Publication Date
- 2026-06-30
AI Technical Summary
Existing methods for detecting permanganate ions are complex and time-consuming, while traditional fluorescent probe detection methods suffer from large errors, making it difficult to achieve rapid and accurate trace detection.
A carbon dot-functionalized lanthanide metal-organic framework material was used to prepare carbon dots by using grapefruit peel as a biomass raw material. These carbon dots were then combined with the lanthanide metal-organic framework material to form a ratiometric fluorescent probe for the detection of permanganate ions in water.
It achieves high sensitivity and low error in the detection of permanganate ions, has rapid and simple detection capabilities, and can accurately identify and reduce environmental interference.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of carbon dot and lanthanide metal-organic framework (MOF) materials, specifically to the preparation and application of carbon dot-functionalized lanthanide MOF materials that can be detected by permanganate ions in water. Background Technology
[0002] Permanganate (MnO4) - MnO4 has strong oxidizing properties and is widely used in water treatment. It can treat not only drinking water but also groundwater and organic pollutants. However, long-term exposure to excessive amounts of MnO4... - It can irritate the human respiratory and nervous systems, posing significant harm to both the environment and human health. The U.S. Environmental Protection Agency (EPA) lists permanganate as a global threat. Therefore, high-speed and accurate detection of MnO4 is crucial. - This is of paramount importance. Currently, commonly used detection methods mainly include titration, electrochemical methods, spectrophotometry, gas chromatography, high-performance liquid chromatography, and Raman spectroscopy. However, these methods all have some limitations. Titration is more suitable for detecting high concentrations, while other methods are complex and time-consuming. In comparison, fluorescent probes have become a more popular detection method among researchers due to their speed, convenience, and high sensitivity.
[0003] Lanthanide metal-organic frameworks (Ln-MOFs), especially europium (Eu)-centered metal-organic frameworks, possess numerous advantages, such as strong visible light emission, abundant functional sites, stable emission, long decay lifetime, and large Stokes shift. The ligand tunability, substrate quenching, and "antenna effect" of metal ions in Ln-MOFs can generate fluorescence responses, demonstrating their suitability for constructing ratiometric fluorescence sensors. Carbon dots (CDs), as common guest molecules, are primarily composed of abundant functional groups / polymer chains and sp... 2 / sp 3Carbon dot matrix is composed of a carbon skeleton. Due to its small pore size and low toxicity, luminescent stability, and good solubility, it has attracted considerable attention from researchers. Currently, constructing carbon dots using biomass raw materials is a hot research area, not only significantly increasing the reuse rate of fruit peels and biowaste, but also being more environmentally friendly, hygienic, and safe. Furthermore, the unique structural properties of biomass carbon dots, with their surface rich in carboxyl groups (-COOH) and hydroxyl groups (-OH), provide an excellent platform for subsequent coordination. Using grapefruit peel as a precursor, biomass carbon dots employ a surface passivation strategy to improve their fluorescence stability and dispersibility. Simultaneously, functional group grafting modification introduces active groups, strengthening their interfacial binding ability with the metal-organic framework, laying the foundation for the construction of subsequent composite systems. A ratiometric fluorescence sensor with two emission peaks, compared to traditional fluorescence sensors with a single emission peak, can reduce detection errors and minimize environmental interference with the detection results. Ratiometric fluorescent probes have one more fluorophore than single-signal fluorescent probes; selecting the appropriate ratio helps achieve visual quantitative detection of target analytes, greatly improving detection accuracy and stability. Therefore, it is necessary to develop a sensitive, rapid, and convenient method for detecting trace amounts of MnO4. - Fluorescent methods for ion detection have attracted much attention. Summary of the Invention
[0004] To address the aforementioned problems, the present invention aims to provide the preparation and application of carbon dot-functionalized lanthanide metal-organic framework materials that can be detected by permanganate ions in water.
[0005] To achieve the above objectives, the present invention provides the following technical solution: Preparation and application of carbon dot-functionalized lanthanide metal-organic framework materials that can be detected by permanganate ions in water, comprising the following steps:
[0006] S1, Select raw materials: europium nitrate, pyromellitic acid, grapefruit peel;
[0007] S2, Dissolve pyromellitic acid in anhydrous ethanol and stir;
[0008] S3, Add europium nitrate solution to the solution obtained in S2 and stir;
[0009] S4, let stand, centrifuge to collect the white precipitate, wash and dry to obtain white lanthanide metal-organic framework material;
[0010] S5. After drying and crushing the grapefruit peel, add deionized water and transfer it to a high-pressure reactor for reaction.
[0011] S6. Centrifuge the solution obtained in S5, take the supernatant and filter it through a microporous filter membrane.
[0012] S7. The solution obtained in S6 is purified by dialysis to obtain a pale yellow carbon dot solution.
[0013] S8. The carbon dot solution obtained in S7 is mixed with the lanthanide metal-organic framework material in S4 to obtain carbon dot-functionalized lanthanide metal-organic framework material.
[0014] S9 uses the material obtained in S8 for the detection of permanganate ions in water.
[0015] Preferably, in both steps S2 and S3, the mixture is stirred at room temperature for 60 minutes.
[0016] Preferably, in step S4, the standing time is 24 hours, the drying temperature is 60 ℃, and the time is 24 hours.
[0017] Preferably, in step S5, the drying time is 24 hours, the drying temperature is 60 °C, the reaction temperature is 200 °C, and the reaction time is 24 hours.
[0018] Preferably, the microporous filter membrane size in step S6 is 0.22 µm.
[0019] Preferably, in step S7, a dialysis membrane with a molecular weight cutoff of 500 Da is used at a ratio of 1:100, and the reaction time is 24 hours.
[0020] Preferably, in step S8, the lanthanide metal-organic framework material is 50 mg, the carbon dot solution is 10 mL, the mixture is stirred at room temperature for 24 hours, the precipitate is collected by centrifugation, and then dried at 60 °C for 24 hours.
[0021] Preferably, the detection in step S9 is the selectivity, anti-interference ability, and sensitivity of the material for recognizing permanganate ions in water.
[0022] Compared with the prior art, the beneficial effects of the present invention are: the present invention uses lanthanide europium ions (Eu) 3+ Lanthanide metal-organic frameworks are formed using pyromellitic trimethylolpropionic acid (TMA), which has a symmetrical structure and multiple coordination sites, and then compounded with carbon dots to obtain ratiometric fluorescent probes, which can more sensitively and accurately identify and detect permanganate ions in water. Attached Figure Description
[0023] Figure 1 This is a schematic diagram illustrating the synthesis of carbon dot-functionalized lanthanide metal-organic framework materials that can be used for permanganate recognition in water bodies according to the present invention.
[0024] Figure 2XRD patterns of simulated single crystals of Y-CDs@Eu-MOFs, Eu-MOFs, and La(TMA)(H2O)6 in this invention (a); FT-IR spectra of Y-CDs@Eu-MOFs and Eu-MOFs (b); XPS full spectrum of Y-CDs@Eu-MOFs and Eu-MOFs (c); Zeta potential histograms of Eu-MOFs, Y-CDs, and Y-CDs@Eu-MOFs (d).
[0025] Figure 3 The excitation pattern (a) and emission pattern (b) of Y-CDs in this invention are shown in the inset, with the corresponding CIE diagrams; the excitation pattern (c) and emission pattern (d) of Eu-MOFs are shown in the inset, with the corresponding CIE diagrams.
[0026] Figure 4 The following are excitation spectra of Y-CDs and Eu-MOFs in this invention: (a); emission spectra of Y-CDs@Eu-MOFs samples at 306 nm, 310 nm, and 314 nm (b); emission spectra of Y-CDs@Eu-MOFs samples at different excitation wavelengths (Ex = 306 / 307 / 308 / 309 / 310 nm) (c); and emission spectrum of Y-CDs@Eu-MOFs samples at 308 nm (d).
[0027] Figure 5 The emission spectra of the Y-CDs@Eu-MOFs sample in different anion solutions are shown in (a); with the addition of MnO4 - Changes in the coordinates of Y-CDs@Eu-MOFs in the CIE chromaticity diagram before and after (b);
[0028] Figure 6 The ratio of fluorescence emission peaks of the Y-CDs@Eu-MOFs sample in different anion solutions in this invention (I) 616 / I 399 (a); Y-CDs@Eu-MOFs samples affect MnO4 in the presence of other interfering components. - The ratio of the response to the fluorescence emission peak (I) 616 / I 399 (b); Y-CDs@Eu-MOFs samples at different concentrations (10-2000 µM) of MnO4 - The corresponding fluorescence intensity I in the solution 616 and I 399 Heat map (c); MnO4 at different concentrations (10-2000 µM) for Y-CDs@Eu-MOFs samples. - The ratio of the fluorescence intensity in the solution to its corresponding fluorescence intensity (I) 616 / I 399The linear relationship between (d) and ( ). Detailed Implementation
[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030] Example 1:
[0031] See Figure 1 The preparation and application of a carbon dot-functionalized lanthanide metal-organic framework material that can be detected by permanganate ions in water are described below:
[0032] S1, Select raw materials: europium nitrate, pyromellitic acid, grapefruit peel;
[0033] S2, Dissolve pyromellitic acid in anhydrous ethanol and stir;
[0034] S3, Add europium nitrate solution to the solution obtained in S2 and stir;
[0035] S4, let stand, centrifuge to collect the white precipitate, wash and dry to obtain white lanthanide metal-organic framework material;
[0036] S5. After drying and crushing the grapefruit peel, add deionized water and transfer it to a high-pressure reactor for reaction.
[0037] S6. Centrifuge the solution obtained in S5, take the supernatant and filter it through a microporous filter membrane.
[0038] S7. The solution obtained in S6 is purified by dialysis to obtain a pale yellow carbon dot solution.
[0039] S8. The carbon dot solution obtained in S7 is mixed with the lanthanide metal-organic framework material in S4 to obtain carbon dot-functionalized lanthanide metal-organic framework material.
[0040] S9 uses the material obtained in S8 for the detection of permanganate ions in water.
[0041] Furthermore, in both steps S2 and S3, the mixture is stirred at room temperature for 60 minutes.
[0042] Furthermore, in step S4, the standing time is 24 hours, the drying temperature is 60 ℃, and the time is 24 hours.
[0043] Furthermore, in step S5, the drying time is 24 hours, the drying temperature is 60 °C, the reaction temperature is 200 °C, and the reaction time is 24 hours.
[0044] Furthermore, in step S6, the size of the microporous filter membrane is 0.22 µm.
[0045] Furthermore, in step S7, a dialysis membrane with a molecular weight cutoff of 500 Da is used at a ratio of 1:100, and the reaction time is 24 hours.
[0046] Furthermore, in step S8, the lanthanide metal-organic framework material is 50 mg, the carbon dot solution is 10 mL, the mixture is stirred at room temperature for 24 hours, the precipitate is collected by centrifugation, and then dried at 60 °C for 24 hours.
[0047] Furthermore, the detection in step S9 is the selectivity, anti-interference ability, and sensitivity of the material for recognizing permanganate ions in water.
[0048] Among them, the prepared carbon dot functionalized lanthanide metal-organic framework materials were used for selective testing of different anions in aqueous solution: at room temperature, 3 mg of Y-CDs@Eu-MOFs sample was weighed and dispersed in 4 mL of water, and 1 mL of 10% concentration was added. -2 mol / L anion solution (MnO4 - CO3 2- I - S 2- NO3 - S2O3 2- CH3COO - ,Br - SO4 2- F - HCO3 - NO2 - Cl - The mixture was then sonicated for 30 minutes to form a homogeneous and stable anion-containing solution, and the prepared solution was subjected to fluorescence testing.
[0049] The prepared carbon dot-functionalized lanthanide metal-organic framework (Y-CDs@Eu-MOFs) was used to test its anti-interference ability for the detection of permanganate in the presence of different anions: At room temperature, 3 mg of Y-CDs@Eu-MOFs sample was weighed and dispersed in 4 mL of water, and 1 mL of a 10% concentration of [unspecified substance] was added. -2 mol / L anion solution (MnO4 - CO3 2- I -S 2- NO3 - S2O3 2- CH3COO - ,Br - SO4 2- F - HCO3 - NO2 - Cl - ), then add a concentration of 10 -2 A mol / L aqueous solution of permanganate was prepared. The mixture was then sonicated for 30 minutes to form a homogeneous and stable solution containing anions. Finally, the prepared solution was subjected to fluorescence testing.
[0050] Sensitivity testing of the prepared carbon dot-functionalized lanthanide metal-organic framework (Y-CDs@Eu-MOFs) for permanganate detection: The experimental sensitivity was calculated by measuring the fluorescence intensity of permanganate at different concentrations in aqueous solution. 3 mg of Y-CDs@Eu-MOFs sample was dissolved in 4 mL of water, and 1 mL of the solution was filled with different concentrations of permanganate (0, 2 × 10⁻⁶, 2 × 10⁻⁶). -3 1.5×10 -3 10 -3 5×10 -4 5×10 -5 10 -5 The mixture was then placed in an aqueous solution (M) and sonicated for 30 minutes to form a homogeneous and stable anion-containing solution. Finally, the prepared solution was subjected to a fluorescence test.
[0051] The structure of the samples was characterized, and the samples were lanthanide metal-organic framework materials and carbon dot composite lanthanide metal-organic framework materials.
[0052] XRD spectral analysis: To confirm the successful composite material Y-CDs@Eu-MOFs, a series of structural characterizations were performed on the samples. First, XRD tests were conducted on Eu-MOFs and the composite material Y-CDs@Eu-MOFs. Figure 2 (a) It can be seen that the XRD peaks of the two materials, Y-CDs@Eu-MOFs and Eu-MOFs, almost correspond to the peaks of the simulated XRD of Eu-MOFs single crystal, with no other impurity peaks appearing, and the peak morphologies are also basically consistent without any irregularities, proving that the crystallinity of the material is quite good. This proves that the synthesized composite materials Y-CDs@Eu-MOFs and Eu-MOFs are both pure phases. At the same time, the internal structure of Eu-MOFs was not damaged after the addition of Y-CDs.
[0053] Infrared spectroscopy analysis: Figure 2 (b) It is clearly found that 3410 cm-1 The broad peak at 1610 and 1555 cm⁻¹ corresponds to the OH stretching vibration. The peak in Y-CDs@Eu-MOFs is even broader and stronger, indicating that the hydroxyl groups of Y-CDs form hydrogen bonds with the hydroxyl / oxygen sites of Eu-MOFs, proving a chemical interaction between them; -1 Belongs to the stretching vibration of the aromatic C=C skeleton, 1440, 1372 cm⁻¹ -1 Corresponding to the in-plane bending vibration of the aromatic ring CH, Y-CDs@Eu-MOFs at 1110 cm -1 The newly observed enhanced peak is attributed to the CO stretching vibration of oxidized functional groups such as epoxy groups (COC) on the surface of Y-CDs (this peak is absent in pure Eu-MOFs), directly proving that Y-CDs have been successfully introduced into the Eu-MOF matrix; 764, 530 cm⁻¹ -1 The out-of-plane bending vibration of the aromatic ring CH confirmed the synergistic existence of Eu-MOF ligands (such as benzene-containing organic ligands) and γ-CDs aromatic cores in the composite material. Simultaneously, at 530 cm⁻¹... -1 The peak belongs to the stretching vibration of Eu-O, thus indicating that the Eu atom and the carboxyl group are successfully coordinated.
[0054] XPS Analysis: Figure 2 (c) The composite material after the addition of Y-CDs shows that there are significantly more characteristic peaks of N 1s, which are characteristic peaks of Y-CDs, further proving the successful addition of Y-CDs.
[0055] Zeta potential test analysis: such as Figure 2 (d) Eu-MOFs (-10.8 mV), Y-CDs (-9.36 mV), and the Y-CDs@Eu-MOFs composite (-6.16 mV) are all negatively charged, and the absolute value of the negative potential of the composite is significantly lower than that of the single component. This is attributed to the fact that when Y-CDs and Eu-MOFs are combined, the negatively charged groups (such as carboxyl and hydroxyl groups) on the surface of both interact through electrostatic attraction or hydrogen bonding, partially shielding each other's effective negative charge; or that the specific surface area is reduced due to slight particle agglomeration, resulting in a decrease in the density of exposed negative charge, which ultimately causes the Zeta potential of the composite to shift towards zero potential.
[0056] Furthermore, the performance of the carbon dot functionalized lanthanide metal-organic framework material (Y-CDs@Eu-MOFs) of this invention was characterized.
[0057] Excitation and emission spectra of Y-CDs: Figure 3 (a) and (b) are the excitation and emission spectra of Y-CDs, respectively. The excitation peak of Y-CDs is at 331 nm, and its emission peak is at 422 nm. The CIE diagram in the inset clearly shows that Y-CDs is a blue-emitting carbon dot with coordinates (0.155, 0.089).
[0058] Excitation and emission spectra of Eu-MOFs: Figure 3 (c) is the excitation peak of Eu-MOFs at an emission wavelength of 616 nm. Figure 3 (d) shows its corresponding emission peak. When the excitation wavelength is 258 nm, the emission spectrum shows Eu... 3+ Characteristic peaks include sharp spectral lines at 536, 556, 591, 616, 650, and 691 nm. These spectral lines belong to... 5 D1→ 7 F1 and 5 D0→ 7 F J The (J = 0-4) transition confirms the Eu transition. 3+ Successful introduction and sensitization into the MOF framework. The corresponding CIE coordinates (0.468, 0.299) confirm its red light emission characteristics.
[0059] Optimal excitation wavelength selection for Y-CDs@Eu-MOFs: To determine the optimal excitation wavelength for the composite material in subsequent fluorescence studies, such as... Figure 4 (a) A clear intersection was observed between the excitation wavelengths of Y-CDs and Eu-MOFs at 300 nm. Considering that the peak value of Eu-MOFs at 616 nm is too strong when the excitation wavelength is ≤306 nm, exceeding a certain range, the overlap with Eu-MOFs to the right of the intersection was chosen as the initial monitoring excitation wavelength range, i.e., 306 nm, 310 nm, and 314 nm. Figure 4 (b) The results showed that the ratio I of the two peaks was... 616 / I 399 The values were 1.5316, 0.9174, and 0.5576, respectively. To find the optimal excitation wavelength for subsequent monitoring and fluorescence assays, the range of 306 nm to 310 nm was selected as the excitation wavelength for secondary monitoring. Figure 4 As shown in (c). Ultimately, the fluorescence intensity I was determined to be [value missing] when the excitation wavelength was 308 nm. 616 / I 399 A value of 1.2 was chosen as the optimal excitation wavelength for subsequent fluorescence assays, such as... Figure 4As shown in (d), when the excitation wavelength is 308 nm, there are obvious fluorescence peaks at 399 nm and 616 nm, corresponding to Y-CDs and Eu-MOFs, respectively. The inset shows the CIE chromaticity diagram of the composite material Y-CDs@Eu-MOFs, with coordinates at (0.2723, 0.2252), located between red and blue light, further proving that this is a typical blue-red dual-emission material. After the materials are composited, the light from the carbon dots is significantly blue-shifted from 422 nm to 399 nm. The introduction of electron-withdrawing functional groups and steric hindrance effects both disrupt the conjugated structure, resulting in a significant blue shift of the fluorescence peak.
[0060] Example 2
[0061] This invention utilizes carbon dot-functionalized lanthanide metal-organic framework materials as fluorescent probes for the detection of permanganate.
[0062] Selectivity: 1 mL of anion exchange solution (MnO4) was added sequentially to a 4 mL Y-CDs@Eu-MOFs sample suspension. - CO3 2- I - S 2- NO3 - S2O3 2- CH3COO - ,Br - SO4 2- F - HCO3 - NO2 - Cl - The fluorescence emission spectrum was detected using 308 nm as the excitation wavelength. Figure 5 As can be clearly seen in (a), the addition of MnO4 - After solution treatment, the emission peak of the Y-CDs@Eu-MOFs sample at 616 nm showed obvious quenching, while the fluorescence peak at 399 nm also showed a slight decrease, proving that this material is a typical "double-variable" ratiometric fluorescent probe. The fluorescence intensity of the probe did not change significantly after the addition of other anions. Figure 5 (b) is the addition of MnO4 - After solution treatment, the CIE chromaticity diagram shows a clear shift in coordinates towards the blue region, further confirming the presence of MnO4. - Solution leads to Eu in γ-CDs@Eu-MOFs 3+ Fluorescence quenching at 616 nm was observed. Simultaneously, significant color changes were observed in the composite material before and after identification. Figure 6 (a) It can be found that the Y-CDs@Eu-MOFs composite material is suitable for MnO4 -The solution exhibits a significant quenching phenomenon, with a quenching rate as high as 95.62%. However, after adding other anion solutions, the fluorescence intensity ratio (Ig) decreases. 616 / I 399 No change occurred.
[0063] Interference resistance: Interference resistance is an important indicator of fluorescent probes; therefore, we conducted interference resistance experiments on the Y-CDs@Eu-MOFs material. For example... Figure 6 (b) Add MnO4 to the composite material after adding other anionic solutions. - Solution, fluorescence intensity (I 616 / I 399 The presence of excellent quenching demonstrates that the composite material Y-CDs@Eu-MOFs can be used to identify MnO4. - The solution is unaffected by other anions and has good anti-interference properties.
[0064] Sensitivity: Sensitivity is another important indicator of a fluorescent probe, determining its practical application value. A good linear relationship is key to evaluating the sensitivity of a fluorescent probe. Before performing linearity testing, Figure 6 (c) shows Y-CDs@Eu-MOFs samples after the addition of different concentrations of 10-2000 μM MnO4. - Thermal plots of fluorescence intensity at 616 nm and 399 nm in solution. With MnO4... - As the concentration decreased, the fluorescence intensity of the composite material, especially at 616 nm, changed significantly, with the color of the thermogram changing from blue to red. Meanwhile, MnO4... - The fluorescence intensity of / Y-CDs@Eu-MOFs I 616 / I 399 and MnO4 - The concentration of the solution exhibits an excellent linear relationship, such as... Figure 6 As shown in (d), the linear equation I 616 / I 399 = -244.3143 [C] + 0.9882, where C is MnO4 - The concentration of the solution. The correlation coefficient R. 2 = 0.9965. MnO4 - The concentration range of the solution is 10-2000 μM.
[0065] To determine the sensitivity of carbon dot-functionalized lanthanide metal-organic framework materials to permanganate ions, the LOD value was calculated to be 0.5506 µM using the formula LOD = 3σ / k. This LOD value is significantly lower than that of MnO4 in the "Standards for Drinking Water Quality" (GB5749-2022). - The maximum permissible concentration is 3 mg / L.
[0066] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. Preparation and application of a carbon dot-functionalized lanthanide metal-organic framework material that can be detected by permanganate ions in water, characterized in that... The following are the operating steps: S1, Select raw materials: europium nitrate, pyromellitic acid, grapefruit peel; S2, Dissolve pyromellitic acid in anhydrous ethanol and stir; S3, Add europium nitrate solution to the solution obtained in S2 and stir; S4, let stand, centrifuge to collect the white precipitate, wash and dry to obtain white lanthanide metal-organic framework material; S5. After drying and crushing the grapefruit peel, add deionized water and transfer it to a high-pressure reactor for reaction. S6. Centrifuge the solution obtained in S5, take the supernatant and filter it through a microporous filter membrane. S7. The solution obtained in S6 is purified by dialysis to obtain a pale yellow carbon dot solution. S8. The carbon dot solution obtained in S7 is mixed with the lanthanide metal-organic framework material in S4 to obtain carbon dot-functionalized lanthanide metal-organic framework material. S9 uses the material obtained in S8 for the detection of permanganate ions in water.
2. The carbon dot-functionalized lanthanide metal-organic framework material for detecting permanganate ions in water as described in claim 1, characterized in that: In both steps S2 and S3, the mixture is stirred at room temperature for 60 minutes.
3. The carbon dot-functionalized lanthanide metal-organic framework material for detecting permanganate ions in water as described in claim 1, characterized in that: In step S4, the resting time is 24 hours, the drying temperature is 60 ℃, and the drying time is 24 hours.
4. The carbon dot-functionalized lanthanide metal-organic framework material for detecting permanganate ions in water as described in claim 1, characterized in that: In step S5, the drying time is 24 hours, the drying temperature is 60 °C, the reaction temperature is 200 °C, and the reaction time is 24 hours.
5. The carbon dot-functionalized lanthanide metal-organic framework material for detecting permanganate ions in water as described in claim 1, characterized in that: The microporous filter membrane size in step S6 is 0.22 µm.
6. The carbon dot-functionalized lanthanide metal-organic framework material for detecting permanganate ions in water as described in claim 1, characterized in that: In step S7, a dialysis membrane with a molecular weight cutoff of 500 Da is used at a ratio of 1:100, and the reaction time is 24 hours.
7. The carbon dot-functionalized lanthanide metal-organic framework material for detecting permanganate ions in water as described in claim 1, characterized in that: In step S8, the lanthanide metal-organic framework material is 50 mg, the carbon dot solution is 10 mL, the mixture is stirred at room temperature for 24 hours, the precipitate is collected by centrifugation, and then dried at 60 °C for 24 hours.
8. The carbon dot-functionalized lanthanide metal-organic framework material for detecting permanganate ions in water as described in claim 1, characterized in that: The detection in step S9 is to assess the material's selectivity, anti-interference ability, and sensitivity in recognizing permanganate ions in water.