A biochar-supported iron-manganese MOF derivative, and a preparation method and application thereof
By preparing a biochar-supported FeMn-MOFs@BC catalyst, which activates persulfate to generate a variety of reactive oxygen species, the problem of low removal efficiency of antibiotic pollutants in existing technologies is solved, achieving a highly efficient and environmentally friendly degradation effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LIAONING UNIVERSITY
- Filing Date
- 2024-07-05
- Publication Date
- 2026-06-16
Smart Images
Figure CN118874484B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalytic materials technology, specifically relating to a biochar-supported iron-manganese MOF derivative, its preparation method, and its application. Background Technology
[0002] Antibiotics are widely used to treat and prevent bacterial infections. However, due to inappropriate or excessive use, antibiotics enter ecosystems through various pathways, causing adverse effects on humans and animals. Therefore, they are listed as "emerging pollutants (ECs)."
[0003] Persulfate (PDS) based on advanced oxidation processes (PS-AOPs) is considered one of the most effective technologies for removing antibiotics. It is widely used to remove recalcitrant organic pollutants due to its stronger redox capabilities, longer half-life, and wider pH range.
[0004] Metal-organic frameworks are a class of porous coordination polymers that are self-assembled from inorganic metal ion centers and organic ligands. Due to their advantages such as large specific surface area, controllable pore size, and variable structure, they have attracted widespread attention in the field of heterogeneous catalysis.
[0005] Iron-based metal-organic frameworks (MOFs) have been applied to photocatalysis and PS activation for the degradation of organic pollutants, such as aromatic compounds, organic dyes, and pharmaceuticals, due to their low cost, abundant iron ore resources, and environmental friendliness. MIL-101(Fe) is one of the most representative materials in the MIL-n series (MIL: materials from the Lavoisier Institute). For PDS activation, Fe sites in iron-based MOFs are generally considered active centers. On the other hand, ligand doping is considered an effective means of modulating structural defects in MOFs, exposing more metal sites. Studies have shown that bimetallic doping can accelerate the generation of hydroxyl radicals, sulfate radicals, singlet oxygen, and a series of reactive oxygen species. The addition of biochar can act as a bridge for "electron shuttle," mediating electron transfer processes and thus improving the degradation efficiency of organic pollutants. Summary of the Invention
[0006] To improve the efficiency of catalyst activation of persulfate, this invention synthesizes a biochar-supported iron-manganese MOF derivative, FeMn-MOFs@BC, using hydrothermal synthesis and pyrolysis methods.
[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0008] A biochar-supported iron-manganese MOF derivative is a FeMn-MOFs@BC catalyst. The type of iron-manganese MOF is MIL-101, and the molar mass ratio of Fe:Mn is 1:5 to 5:1.
[0009] The preparation method of the above-mentioned biochar-supported iron-manganese MOF derivative includes the following steps:
[0010] 1) Anhydrous ferric chloride, manganese chloride, and terephthalic acid were added to a 50 mL beaker of N,N-dimethylformamide and the mixture was stirred at room temperature until it became clear. The resulting mixture was then transferred to a hydrothermal reactor for hydrothermal reaction. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, centrifuged, and dried to obtain an orange solid named FeMn-MOFs.
[0011] 2) Dissolve FeMn-MOFs and biochar in water, then stir the mixture thoroughly, sonicate, and dry it. Place the resulting sample in a tube furnace and calcine it at high temperature under nitrogen protection. After calcination, cool it to room temperature and wash the collected black solid with deionized water, which is the modified biochar. Continue washing until the eluent is close to neutral, then dry the modified biochar in a desiccator. Finally, grind the dried modified biochar with a mortar and pestle to obtain the FeMn-MOFs@BC catalyst.
[0012] Furthermore, in the above preparation method, in step 1), the hydrothermal reaction temperature is 120°C and the reaction time is 14 hours.
[0013] Furthermore, in the above preparation method, in step 1), the molar mass ratio of anhydrous ferric chloride to manganese chloride is 1:5 to 5:1.
[0014] Furthermore, in the above preparation method, step 2), the calcination temperature is 900℃ and the duration is 2h.
[0015] Furthermore, in the above preparation method, in step 2), the mass ratio of FeMn-MOFs to biochar is 1:1.
[0016] Furthermore, in the above preparation method, step 2), the types of biochar include wheat straw, corn straw, and rice straw.
[0017] The above-mentioned FeMn-MOFs@BC catalyst is used in the removal of organic pollutants from wastewater using advanced persulfate oxidation technology.
[0018] Further, the above application is carried out as follows: FeMn-MOFs@BC catalyst is added to 50 mL of wastewater containing organic pollutants, and persulfate is added to initiate the reaction and degrade the organic pollutants.
[0019] Furthermore, in the above application, the amount of FeMn-MOFs@BC catalyst added is 0.05-0.5 g / L; the pH of the wastewater is 2-9; the amount of persulfate is 0.25-10 mM; and the organic pollutant is sulfamethoxazole, with an initial concentration of 1-20 mg / L in the wastewater.
[0020] The beneficial effects of this invention are:
[0021] 1. The FeMn-MOFs@BC catalyst provided by this invention, wherein FeMn-MOFs belongs to the MIL-101(Fe) series of metal-organic frameworks, and the doping of manganese can not only adjust the structural defects of MIL-101(Fe) to expose more metal active sites, but also accelerate the electron transfer between interfaces, enhance the conductivity, and improve the electrochemical properties of the material to improve its catalytic performance.
[0022] 2. The FeMn-MOFs@BC catalyst provided by this invention is specifically prepared using a low-cost and low-energy hydrothermal synthesis method and a calcination method. The preparation process is simple, easy to operate, green and clean, and can be prepared on a large scale.
[0023] 3. The FeMn-MOFs@BC catalyst provided by this invention can rapidly activate persulfate to generate various reactive oxygen species and efficiently degrade organic pollutants. The combination of FeMn-MOFs and biochar further increases the specific surface area of the catalyst, shortening the distance between pollutants and active sites, thereby accelerating pollutant degradation. After 30 minutes of reaction, the degradation rate of SMX can reach 97.5%. Attached Figure Description
[0024] Figure 1 These are scanning electron microscope (SEM) images of the FeMn-MOFs precursor (a) and FeMn-MOFs@BC catalyst (b) prepared in this invention.
[0025] Figure 2 These are the XRD patterns of the FeMn-MOFs precursor and FeMn-MOFs@BC catalyst prepared in this invention.
[0026] Figure 3 The graph shows the degradation effect of the FeMn-MOFs@BC catalyst prepared in this invention on sulfamethoxazole (SMX) under different pH conditions.
[0027] Figure 4 This is a graph showing the degradation effect of the FeMn-MOFs@BC catalyst prepared in this invention on sulfamethoxazole (SMX) after recycling.
[0028] Figure 5This is a graph showing the degradation effect of the FeMn-MOFs@BC catalyst prepared in this invention on sulfamethoxazole (SMX) in actual water bodies. Detailed Implementation
[0029] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein. Those skilled in the art can make similar improvements without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0030] Example 1
[0031] (I) The preparation method is as follows:
[0032] 1) Add 2 mM anhydrous ferric chloride (FeCl3), 2 mM manganese chloride (MnCl2·4H2O), and 1 mM terephthalic acid (H2BDC) to a beaker containing 50 mL of N,N-dimethylformamide (DMF) and stir at room temperature for 2 hours until the mixture is clear; then transfer the mixture to a 70 mL hydrothermal reactor and react at 120 °C for 14 hours; after the reaction is complete, cool to room temperature, filter to obtain an orange solid product, wash the orange solid product twice with DMF and anhydrous ethanol respectively, and centrifuge; finally, dry the obtained product at 60 °C for 8 hours for later use, and name the orange solid FeMn-MOFs.
[0033] Anhydrous FeCl3 and MnCl2·4H2O were mixed in different molar ratios of 5:1, 3:1, 1:1, 1:3, and 1:5 to obtain a series of Fe... x Mn y -MOFs composite systems were named Fe5Mn1-MOFs, Fe3Mn1-MOFs, Fe1Mn1-MOFs, Fe1Mn3-MOFs, and Fe1Mn5-MOFs, respectively.
[0034] 2) Dissolve 1.0 g of FeMn-MOFs and 1.0 g of rice straw in 50 mL of water, then stir the mixture thoroughly for 30 minutes, sonicate, and dry in a drying oven at 60 °C for 14 hours; transfer the obtained sample to a tube furnace and calcine at 900 °C for 2 hours (nitrogen protection, heating rate 10 °C / min); after calcination, cool to room temperature, wash the collected black solid with deionized water to obtain modified biochar, until the eluent is nearly neutral, and then dry the modified biochar in a desiccator; finally, grind the dried modified biochar with a mortar and pestle to obtain the FeMn-MOFs@BC catalyst.
[0035] (II) Characterization
[0036] Figure 1 Figure 1 shows scanning electron microscope (SEM) images of the FeMn-MOFs precursor (a) and the FeMn-MOFs@BC catalyst (b) prepared in Example 1 of this invention. The morphology of the synthesized bimetallic FeMn-MOFs precursor is shown in Figure 1(a). The precursor surface has a smooth but irregular octahedral structure with a size ranging from 500 nm to 1000 nm. The morphology of the pyrolyzed Fe3Mn1-MOFs@BC is shown in Figure 1(b). FeMn-MOFs@BC exhibits a relatively smooth polyhedral surface successfully loaded onto shell-like biochar, with a size ranging from 500 nm to 1000 nm.
[0037] Figure 2 The XRD patterns of the FeMn-MOFs precursor and FeMn-MOFs@BC catalyst prepared in Example 1 of this invention are shown. Diffraction peaks were observed at 9.1°, 9.8°, 16.5°, 25.4°, and 33.1° for FeMn-MOFs, which are in good agreement with previous reports, confirming the formation of a MIL-101 type MOF structure. The XRD pattern of FeMn-MOFs@BC clearly shows an amorphous carbon phase, with a distinct peak between 20° and 23°, indicating that the material is a typical carbonaceous material and demonstrating the successful loading of MOFs onto biogenic carbon.
[0038] Example 2
[0039] The FeMn-MOFs@BC catalyst was prepared according to the preparation method in Example 1, except that the 1.0 g rice straw in the preparation step was replaced with 1.0 g corn straw and 1.0 g wheat straw, respectively. The rest of the preparation method remained unchanged.
[0040] Example 3
[0041] The three different types of FeMn-MOFs@BC catalysts prepared were used to degrade sulfamethoxazole (SMX) in a FeMn-MOFs@BC / PDS reaction system: 0.015 g of FeMn-MOFs@BC catalyst was added to a beaker containing 50 mL of wastewater containing 10 mg / L sulfamethoxazole, and 1 mM persulfate (PDS) was added to initiate the reaction and degrade sulfamethoxazole. The results are shown in Table 1.
[0042] Table 1. Degradation effect of FeMn-MOFs@BC catalysts of three different biochar types on sulfamethoxazole
[0043] Types of biochar rice straw corn stalks wheat straw Sulfamethoxazole degradation rate 95％ 93％ 92％
[0044] Example 4
[0045] The FeMn-MOFs@BC catalyst prepared in Example 1 was used to degrade sulfamethoxazole (SMX) in a FeMn-MOFs@BC / PDS reaction system: 0.015 g of FeMn-MOFs@BC catalyst was added to a beaker containing 50 mL of wastewater containing 10 mg / L sulfamethoxazole. The pH of the wastewater was 2-11. 1 mM persulfate (PDS) was added to initiate the reaction and degrade sulfamethoxazole.
[0046] Figure 3 This invention demonstrates the degradation effect of the FeMn-MOFs@BC catalyst on sulfamethoxazole under different pH conditions. The FeMn-MOFs@BC catalyst exhibits good catalytic performance over a wide pH range and shows good applicability in treating complex real-world aquatic environments.
[0047] Example 5
[0048] The cyclic performance of the FeMn-MOFs@BC catalyst prepared in Example 1 in the FeMn-MOFs@BC / PDS reaction system for the degradation of sulfamethoxazole (SMX) was investigated: 0.015 g of FeMn-MOFs@BC catalyst was added to a beaker containing 50 mL of wastewater containing 10 mg / L sulfamethoxazole, and 1 mM PDS was added to initiate the reaction and degrade sulfamethoxazole. After the reaction, the FeMn-MOFs@BC catalyst was filtered, dried, and the above steps were repeated.
[0049] Figure 4 The FeMn-MOFs@BC catalyst prepared in this invention was used for the degradation of sulfamethoxazole (SMX) after recycling. Even after four reuses, the sulfamethoxazole removal rate remained above 90%, demonstrating the stable catalytic activity of FeMn-MOFs@BC in the FeMn-MOFs@BC / PDS system. This indicates that FeMn-MOFs@BC has good reusability in the SMX degradation process.
[0050] Example 6
[0051] Actual water body test of the degradation of sulfamethoxazole (SMX) by the FeMn-MOFs@BC catalyst prepared in Example 1 in the FeMn-MOFs@BC / PDS reaction system: 0.015g of FeMn-MOFs@BC catalyst was added to a beaker containing 50mL of groundwater, Dingxiang Lake water and Liaohe River water (all containing 10mg / L sulfamethoxazole), and 1mM PDS was added to initiate the reaction to degrade sulfamethoxazole.
[0052] Figure 5The degradation of sulfamethoxazole by the FeMn-MOFs@BC catalyst prepared in this invention was demonstrated in actual water bodies. The degradation efficiency of sulfamethoxazole by FeMn-MOFs@BC remained around 95% in different actual water bodies, proving that FeMn-MOFs@BC exhibits strong anti-interference performance when exerting its co-catalytic effect, making it highly valuable for practical applications.
Claims
1. A biochar-supported iron-manganese MOF derivative, characterized in that, The biochar-supported iron-manganese MOF derivative is a FeMn-MOFs@BC catalyst, and the type of iron-manganese MOF is MIL-101; The method for preparing a biochar-supported iron-manganese MOF derivative includes the following steps: 1) Anhydrous FeCl3, MnCl2·4H2O, and terephthalic acid were added to a 50 mL beaker of N,N-dimethylformamide, and the mixture was stirred and clarified at room temperature. The resulting mixture was transferred to a hydrothermal reactor and hydrothermally reacted at 120 °C for 14 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, centrifuged, and dried to obtain an orange solid named FeMn-MOFs. Anhydrous FeCl3 and MnCl2·4H2O were mixed in different molar ratios of 5:1, 3:1, 1:1, 1:3, and 1:5, respectively. 2) Dissolve FeMn-MOFs and wheat straw, corn straw or rice straw in water, then stir the mixture thoroughly, sonicate and dry it; place the obtained sample in a tube furnace and calcine at 900℃ for 2h under nitrogen protection. After calcination, cool to room temperature and wash the collected black solid with deionized water to obtain modified biochar until the eluent is neutral. Then dry the modified biochar in a desiccator; finally, grind the dried modified biochar with a mortar and pestle to obtain FeMn-MOFs@BC catalyst.
2. The biochar-supported iron-manganese MOF derivative according to claim 1, characterized in that, In step 2), the mass ratio of FeMn-MOFs to wheat straw, corn straw, or rice straw is 1:
1.
3. The application of the biochar-supported iron-manganese MOF derivative as described in claim 1 in the removal of organic pollutants from wastewater using persulfate advanced oxidation technology.
4. The application according to claim 3, characterized in that, The method is as follows: FeMn-MOFs@BC catalyst is added to 50 mL of wastewater containing organic pollutants, and persulfate is added to initiate the reaction and degrade the organic pollutants.
5. The application according to claim 4, characterized in that, The FeMn-MOFs@BC catalyst is added at a rate of 0.05-0.5 g / L; the pH of the wastewater is 2-9; the amount of persulfate is 0.25-10 mM; and the organic pollutant is sulfamethoxazole, with an initial concentration of 1-20 mg / L in the wastewater.