Application of Fe-Co / COF photocatalyst in photocatalytic degradation of tetracycline
By introducing Fe and Co into the COF framework through Fe-Co/COF bimetallic site catalysts, the problem of insufficient activity of traditional photocatalysts is solved, and efficient enrichment and degradation of macrocyclic lactone antibiotics are achieved. The catalyst preparation is simple and has good stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NINGBO INST OF NORTHWESTERN POLYTECHNICAL UNIV
- Filing Date
- 2023-12-30
- Publication Date
- 2026-07-31
AI Technical Summary
Existing technologies are difficult to effectively enrich and degrade macrolide antibiotics, and traditional photocatalysts such as COF have insufficient activity. Single-metal site catalysts also face challenges in terms of photocatalytic activity and stability.
The Fe-Co/COF bimetallic site catalyst is used to improve the photoactivity and catalytic reaction efficiency of the catalyst by introducing Fe and Co into the COF framework structure and utilizing the synergistic effect of the bimetallic sites and optimizing the electronic structure.
It achieves efficient enrichment and rapid degradation of macrolide antibiotics. The catalyst preparation method is simple, the reaction conditions are mild, and the performance is superior to single-metal site catalysts.
Smart Images
Figure CN118022836B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photocatalyst technology, specifically to an Fe-Co / COF photocatalyst and its preparation method. Background Technology
[0002] Macrolide antibiotics, as a class of broad-spectrum antibiotics, have caused serious environmental problems in recent years due to their unregulated production and use, with erythromycin being a particularly typical example. Remediation of antibiotic-contaminated aquatic environments is now urgent. Current processes for antibiotic removal, such as precipitation, coagulation, adsorption separation, and advanced oxidation, cannot simultaneously achieve ideal enrichment and degradation functions. To further promote the removal of macrolide antibiotics from the aquatic environment, considering energy costs and process complexity, this invention designs and constructs a catalyst main structure from a microscopic perspective, selects activity-regulating components, and integrates multifunctional modules to construct a highly stable photocatalyst with both enrichment and degradation functions to achieve the removal of residual antibiotics in the aquatic environment.
[0003] To achieve the targeted and rapid capture and enrichment of macrolide antibiotics in aquatic environments, the catalyst host structure should possess a large specific surface area, good stability, and ultra-small pore size matching the substrate antibiotic molecules. Extensive literature review has revealed that COF materials, constructed from stable covalent bonds, possess globally periodic and precisely tunable ultra-small pore structures, and have been proven in recent years to achieve rapid enrichment of specific antibiotic molecules in aquatic environments. However, it is undeniable that the inherent non-metallic, purely organic framework of COFs leads to the absence of active components or insufficient performance; when used alone as photocatalysts, their photoactivity and catalytic activity are not satisfactory. Therefore, it is crucial to introduce active components into the COF framework structure using suitable methods to simultaneously improve the photoactivity and catalytic reaction rate of COF catalysts. Thus, attempting to improve the photoactivity and catalytic activity of COF catalysts by selecting appropriate building blocks and optimizing the methods for introducing active components into the COF framework structure, thereby synergistically addressing the aforementioned bottlenecks and constructing highly enriched and active COF catalysts, has significant practical implications.
[0004] Fe is widely used as a heterocatalyst due to its high abundance in nature, low cost, and low toxicity. Recent studies have confirmed that Fe porphyrin COFs have become a research hotspot in photocatalysis due to their excellent photoactivity. Previous work within our group revealed that the slow conversion of Fe(III) / Fe(II) and the strict pH requirements in the microscopic catalytic reaction process limit the photocatalytic activity of Fe-based catalysts to some extent. Our research found that the introduction of different active metals into the COF framework can effectively improve the catalyst's band gap structure, promote the separation efficiency of photogenerated charges and holes during the photocatalytic reaction, and enhance the catalyst's photocatalytic activity.
[0005] Because the single-metal site catalysts Fe / COF and Co / COF have fixed electronic structures, they are easily limited by the adsorption strength of key intermediates during catalysis, making it challenging to achieve high activity and stability. This invention employs a Fe-Co / COF bimetallic site catalyst with synergistic interatomic interactions and an optimizable electronic structure. This allows for effective regulation of intermediate adsorption and proton-electron transfer during catalysis, potentially leading to superior performance. Summary of the Invention
[0006] This invention provides a Fe-Co / COF photocatalyst with both enrichment and degradation functions and its preparation method. The catalyst is applied to the removal of antibiotics in the aquatic environment. The preparation method is simple and the reaction conditions are mild.
[0007] Specifically, it is implemented as follows: A Fe-Co / COF photocatalyst, characterized by the following structural formula:
[0008]
[0009] The preparation method of the above Fe-Co / COF photocatalyst includes the following steps:
[0010] (1) Using Fe-tetraaminoporphyrin and 2,2-bipyridine-5,5-dialdehyde as raw materials, and a mixture of o-dichlorobenzene, n-butanol and acetic acid as reaction solvent, the mixture was placed in a heat-resistant glass tube. The air in the system was removed by three liquid nitrogen freezing-evacuation methods, and finally the glass tube was sealed with high temperature.
[0011] (2) After sealing, heat the reaction tube to 100-150 °C and react for 3-7 days to obtain ordered Fe-COF crystals;
[0012] (3) Fe-COF crystals were immersed in cobalt acetate acetone solution to derivatize Fe-TABP-Co-COF, which was then washed with water and dried to obtain the finished product.
[0013] Furthermore, in step (1) of the preparation method, the molar ratio of Fe-tetraaminoporphyrin and 2,2-bipyridine-5,5-dialdehyde is 1:0.25-4.
[0014] Furthermore, in step (1) of the preparation method, the volume ratio of o-dichlorobenzene, n-butanol and acetic acid in the reaction solvent of the mixed system is 1:1:0.2-2.
[0015] Furthermore, in step (1) of the preparation method, the concentration of the raw material in the reaction solvent is 0.01-0.05 mmol / mL.
[0016] Furthermore, in step (1) of the preparation method, the glass tube is sealed by high temperature through flame calcination.
[0017] Furthermore, in step (3) of the preparation method, the concentration of the cobalt acetate acetone solution is 5-10 g / mL.
[0018] Advantages and effects of the present invention compared with the prior art:
[0019] 1. This invention provides a Fe-Co / COF composite photocatalyst with precise bimetallic sites and its preparation method. Specifically, a COF substrate material with a multi-metal coordination environment is constructed using porphyrin and bipyridine molecules. Fe porphyrin molecules, due to their excellent photosensitivity and stability, and bipyridine molecules, due to their nitrogen-rich structure, are ideal choices for catalyst framework construction units, facilitating post-modification with active metals. Imine bonds act as connecting bridges, ensuring the large extended conjugated structure of the COF framework and exhibiting high stability. A highly crystalline Fe-TABP-COF substrate material is prepared by a flame calcination and tube sealing reaction. Subsequently, Co is post-modified into the bipyridine sites within the Fe-TABP-COF framework using an impregnation method to obtain a bimetallic Fe-TABP-Co-COF photocatalyst with a precise coordination environment.
[0020] 2. The novel Fe-Co / COF photocatalyst obtained in this invention exhibits superior photocatalytic performance compared to bare COF, single-metal site Fe / COF, and Co / COF, based on the synergistic effect between Fe and Co bimetallic sites, and has broad application prospects.
[0021] 3. The Fe-Co / COF photocatalyst obtained by this invention has both strong enrichment and rapid degradation functions, which can be applied to the removal of antibiotics in the aquatic environment. The preparation method is simple and the reaction conditions are mild. Attached Figure Description
[0022] Figure 1 This is the XPS spectrum of Fe / Co successfully introduced into COF in Example 1.
[0023] Figure 2 The images show the ultraviolet absorption spectra of the products from Example 1 and Comparative Examples 1-3.
[0024] Figure 3 Impedance spectra of the products of Example 1 and Comparative Examples 1-2.
[0025] Figure 4 The photocurrent spectra of the products of Example 1 and Comparative Examples 1-2 are shown.
[0026] Figure 5 The graphs show the photodegradation performance of tetracycline in the products of Example 1 and Comparative Examples 1-2.
[0027] Figure 6 The XRD patterns are of the products from Examples 1-5. Detailed Implementation
[0028] Example 1
[0029] A method for preparing an Fe-Co / COF photocatalyst includes the following steps:
[0030] (1) Using 0.02 mmol Fe-tetraaminoporphyrin and 0.04 mmol 2,2-bipyridine-5,5-dialdehyde as raw materials, and a mixture of 0.5 mL o-dichlorobenzene, 0.5 mL n-butanol and 0.1 mL acetic acid as reaction solvent, the mixture was placed in a heat-resistant glass tube. The air in the system was removed by three liquid nitrogen freezing-evacuation methods, and the glass tube was finally sealed by flame calcination.
[0031] (2) After sealing, the reaction tube was heated to 150 °C and reacted for 7 days to obtain ordered Fe-COF crystals;
[0032] (3) Fe-COF crystals were immersed in a 10 g / mL cobalt acetate acetone solution to derivatize Fe-TABP-Co-COF, which was then washed with water and dried to obtain the finished product.
[0033] Comparative Example 1
[0034] A method for preparing an Fe / COF photocatalyst includes the following steps:
[0035] (1) Using 0.02 mmol Fe-tetraaminoporphyrin and 0.04 mmol 2,2-bipyridine-5,5-dialdehyde as raw materials, and a mixture of 0.5 mL o-dichlorobenzene, 0.5 mL n-butanol and 0.1 mL acetic acid as reaction solvent, the mixture was placed in a heat-resistant glass tube. The air in the system was removed by three liquid nitrogen freezing-evacuation methods, and the glass tube was finally sealed by flame calcination.
[0036] (2) After sealing, the reaction tube was heated to 150 °C and reacted for 7 days to obtain ordered Fe-COF crystals;
[0037] (3) Fe-COF crystals were immersed in acetone solution to derive Fe-TABP-COF.
[0038] Comparative Example 2
[0039] A method for preparing a Co / COF photocatalyst includes the following steps:
[0040] (1) Using 0.02 mmol Co-tetraaminoporphyrin and 0.04 mmol 2,2-bipyridine-5,5-dialdehyde as raw materials, and a mixture of 0.5 mL o-dichlorobenzene, 0.5 mL n-butanol and 0.1 mL acetic acid as reaction solvent, the mixture was placed in a heat-resistant glass tube. The air in the system was removed by three liquid nitrogen freezing-evacuation methods, and the glass tube was finally sealed by flame calcination.
[0041] (2) After sealing, the reaction tube was heated to 150 °C and reacted for 7 days to obtain ordered Co-COF crystals;
[0042] (3) Co-COF crystals were immersed in acetone solution to derive Co / Fe-COF.
[0043] Comparative Example 3: Commercially available COF photocatalysts
[0044] refer to Figure 1 In the preparation process of Example 1, the N1s spectrum is the binding energy of N in COF and Fe-COF. The binding energy shifted, proving the coordination of N with Fe (Fe-COF); the Fe spectrum is the binding energy of Fe in Fe-COF and Co / Fe-COF, proving the introduction of Fe into the COF system (Fe-COF); the Co spectrum is the binding energy of Co in Co / Fe-COF, proving the introduction of Co into the COF system (Fe / Co-COF).
[0045] refer to Figures 2-5 The bimetallic Fe-Co / COF composite photocatalyst prepared in Example 1, compared with COF, Fe-COF, and Co-COF catalysts, has a wider absorption range for visible light, higher light absorption efficiency, lower resistance, better conductivity, higher photoelectric conversion efficiency, and higher photodegradation efficiency for tetracycline.
[0046] Example 2
[0047] A method for preparing an Fe-Co / COF photocatalyst includes the following steps:
[0048] (1) Using 0.02 mmol Fe-tetraaminoporphyrin and 0.01 mmol 2,2-bipyridine-5,5-dialdehyde as raw materials, and a mixture of 0.5 mL o-dichlorobenzene, 0.5 mL n-butanol and 0.25 mL acetic acid as reaction solvent, the mixture was placed in a heat-resistant glass tube. The air in the system was removed by three liquid nitrogen freezing-evacuation methods, and the glass tube was finally sealed by flame calcination.
[0049] (2) After sealing, the reaction tube was heated to 150 °C and reacted for 5 days to obtain ordered Fe-COF crystals;
[0050] (3) Fe-COF crystals were immersed in a 10 g / mL cobalt acetate acetone solution to derivatize Fe-TABP-Co-COF, which was then washed with water and dried to obtain the finished product.
[0051] Example 3
[0052] A method for preparing an Fe-Co / COF photocatalyst includes the following steps:
[0053] (1) Using 0.02 mmol Fe-tetraaminoporphyrin and 0.005 mmol 2,2-bipyridine-5,5-dialdehyde as raw materials, and a mixture of 0.5 mL o-dichlorobenzene, 0.5 mL n-butanol and 0.5 mL acetic acid as reaction solvent, the mixture was placed in a heat-resistant glass tube. The air in the system was removed by three liquid nitrogen freezing-evacuation methods, and the glass tube was finally sealed by flame calcination.
[0054] (2) After sealing, the reaction tube was heated to 100 °C and reacted for 3 days to obtain ordered Fe-COF crystals;
[0055] (3) Fe-COF crystals were immersed in a 10 g / mL cobalt acetate acetone solution to derivatize Fe-TABP-Co-COF, which was then washed with water and dried to obtain the finished product.
[0056] Example 4
[0057] A method for preparing an Fe-Co / COF photocatalyst includes the following steps:
[0058] (1) Using 0.04 mmol Fe-tetraaminoporphyrin and 0.04 mmol 2,2-bipyridine-5,5-dialdehyde as raw materials, and a mixture of 0.5 mL o-dichlorobenzene, 0.5 mL n-butanol and 0.75 mL acetic acid as reaction solvent, the mixture was placed in a heat-resistant glass tube. The air in the system was removed by three liquid nitrogen freezing-evacuation methods, and the glass tube was finally sealed by flame calcination.
[0059] (2) After sealing, the reaction tube was heated to 120 °C and reacted for 4 days to obtain ordered Fe-COF crystals;
[0060] (3) Fe-COF crystals were immersed in a 5 g / mL cobalt acetate acetone solution to derivatize Fe-TABP-Co-COF, which was then washed with water and dried to obtain the finished product.
[0061] Example 5
[0062] A method for preparing an Fe-Co / COF photocatalyst includes the following steps:
[0063] (1) Using 0.02 mmol Fe-tetraaminoporphyrin and 0.08 mmol 2,2-bipyridine-5,5-dialdehyde as raw materials, and a mixture of 0.5 mL o-dichlorobenzene, 0.5 mL n-butanol and 1.0 mL acetic acid as reaction solvent, the mixture was placed in a heat-resistant glass tube. The air in the system was removed by three liquid nitrogen freezing-evacuation methods, and the glass tube was finally sealed by flame calcination.
[0064] (2) After sealing, the reaction tube was heated to 120 °C and reacted for 3 days to obtain ordered Fe-COF crystals;
[0065] (3) Fe-COF crystals were immersed in a cobalt acetate acetone solution of 8 g / mL to derivatize Fe-TABP-Co-COF, which was then washed with water and dried to obtain the finished product.
[0066] refer to Figure 6 Examples 1-5 all yielded the Fe-Co / COF photocatalyst of the present invention. Since temperature and time affect the efficiency of the aldehyde-amine condensation reaction, they determine the synthesis efficiency and crystal structure of COF. The performance of the Fe-Co / COF photocatalysts varies slightly, with the Fe-Co / COF photocatalyst prepared in Example 1 exhibiting the best performance.
Claims
1. An application of an Fe-Co / COF photocatalyst in the photocatalytic degradation of tetracycline, characterized in that, Its structural formula is: ； Its preparation method includes the following steps: (1) Using Fe-tetraaminoporphyrin and 2,2-bipyridine-5,5-dialdehyde as raw materials, and a mixture of o-dichlorobenzene, n-butanol and acetic acid as reaction solvent, the mixture was placed in a heat-resistant glass tube. The air in the system was removed by three liquid nitrogen freezing-evacuation methods, and finally the glass tube was sealed with high temperature. (2) After sealing, heat the reaction tube to 100-150 °C and react for 3-7 days to obtain ordered Fe-COF crystals; (3) Fe-COF crystals were immersed in cobalt acetate acetone solution to derivatize Fe-TABP-Co-COF, which was then washed with water and dried to obtain the finished product.
2. The application according to claim 1, characterized in that... In step (1), the molar ratio of Fe-tetraaminoporphyrin and 2,2-bipyridine-5,5-dialdehyde is 1:0.25-4.
3. The application according to claim 1, characterized in that... In step (1), the volume ratio of o-dichlorobenzene, n-butanol and acetic acid in the reaction solvent of the mixed system is 1:1:0.2-2.
4. The application according to claim 1, characterized in that... In step (1), the concentration of the raw material in the reaction solvent is 0.01-0.05 mmol / mL.
5. The application according to claim 1, characterized in that... In step (1), the glass tube is sealed by high temperature through flame calcination.
6. The application according to claim 1, characterized in that... In step (3), the concentration of the cobalt acetate acetone solution is 5-10 g / mL.
7. The application according to claim 1, characterized in that... The preparation method includes the following steps: (1) Fe-tetraaminoporphyrin and 2,2-bipyridine-5,5-dialdehyde in a molar ratio of 1:2 were used as raw materials, and a mixture of o-dichlorobenzene, n-butanol and acetic acid in a volume ratio of 1:1:0.2 was used as the reaction solvent. The mixture was placed in a heat-resistant glass tube, and the air in the system was removed by three liquid nitrogen freezing-evacuation methods. Finally, the glass tube was sealed by flame calcination. (2) After sealing, the reaction tube was heated to 150 °C and reacted for 7 days to obtain ordered Fe-COF crystals; (3) Fe-COF crystals were immersed in a 10 g / mL cobalt acetate acetone solution to derivatize Fe-TABP-Co-COF, which was then washed with water and dried to obtain the finished product.