A cof-tpbd / cof-tpma composite photocatalyst and a preparation method and application thereof
By in-situ growing COF-TpMA on COF-TpBD to form a composite photocatalyst, the problem of the difficulty in degrading tetracyclic antibiotics was solved, achieving high efficiency in photocatalytic degradation performance and stability, and improving the charge separation ability of the photocatalyst.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HARBIN UNIV OF SCI & TECH
- Filing Date
- 2024-01-24
- Publication Date
- 2026-05-26
AI Technical Summary
Tetracyclic antibiotics are difficult to degrade spontaneously in nature, and existing photocatalysts are insufficient in terms of photoinduced charge separation and degradation efficiency, which affects human health and ecological balance.
A COF-TpBD/COF-TpMA composite photocatalyst was used. By growing COF-TpMA in situ on COF-TpBD, a heterojunction was formed, which promoted charge separation and improved photocatalytic degradation performance.
The photocatalytic degradation efficiency of tetracyclic antibiotics was significantly improved. After 3 hours of xenon lamp irradiation, the degradation rate reached 86-87%, with maximum degradation rate constants of 1.0101 and 0.0115 min⁻¹, and the catalyst exhibited excellent stability.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of photocatalyst technology, and in particular to a COF-TpBD / COF-TpMA composite photocatalyst, its preparation method, and its application. Background Technology
[0002] Tetracyclic antibiotics are widely used in medicine, agriculture, aquaculture, and animal husbandry; however, their overuse poses a significant threat to human health and ecological balance. Tetracyclic antibiotics are difficult to degrade spontaneously in nature, and residues have been detected in many types of food, greatly threatening human health and safety. For tetracyclic antibiotic pollution in aquatic environments, constructing heterojunction photocatalyst systems is one effective way to achieve solar-driven decomposition of tetracyclic antibiotic pollutants. Effective photoinduced charge separation is crucial for achieving high photocatalytic activity in degrading organic pollutants.
[0003] Covalent organic frameworks (COFs) are crystalline solids composed of organic monomers linked by strong covalent bonds. They are porous framework materials with advantages such as large specific surface area, low framework density, high stability, programmable structure, and high carrier transport rate. The framework structure of COFs and their crystal properties similar to those of carbon nanomaterials allow them to carry sufficient active sites and precisely control the coordination environment between them and the active sites.
[0004] Among many covalent organic frameworks (COFs), COF-TpMA and COF-TpBD exhibit high photocatalytic activity due to their narrow band gap, low energy level, and good optical response characteristics. COF-TpMA has good photodegradation performance, while COF-TpBD forms a heterojunction with COF-TpMA, which can promote charge transfer. Summary of the Invention
[0005] The purpose of this invention is to provide a COF-TpBD / COF-TpMA composite photocatalyst, its preparation method, and its application.
[0006] To achieve the above objectives, the present invention provides the following solution:
[0007] This invention provides a composite photocatalyst for the degradation of tetracyclic antibiotics, wherein the composite photocatalyst is a COF-TpBD / COF-TpMA composite photocatalyst.
[0008] The present invention also provides a method for preparing the composite photocatalyst, comprising the following steps:
[0009] (1) Disperse COF-TpBD, trialdehyde-modified triphenol and acetic acid in a mixed solution and sonicate, then add melamine and sonicate.
[0010] (2) After passing nitrogen gas through the dispersion obtained in step (1) and evacuating it, the dispersion was degassed and heated by freezing and thawing to obtain the crude product.
[0011] (3) The crude product is filtered, washed and purified to obtain the composite photocatalyst.
[0012] Preferably, the preparation method of the COF-TpBD is as follows: trialdehyde-m-triphenol and benzidine are added to glycerol and stirred for 5 hours, then nitrogen gas is purged and vacuum is applied, followed by heating for 72 hours. The dispersion is then washed with anhydrous ethanol and dried at 80°C for 12 hours.
[0013] Preferably, the ratio of COF-TpBD, trialdehyde m-triphenol, and acetic acid is 2.86 mg: 17.73 mg: 0.4 ml.
[0014] Preferably, the mass ratio of melamine to COF-TpBD is 8:2.86.
[0015] Preferably, the concentration of the acetic acid is 4M.
[0016] Preferably, the mixed solution comprises mesitylene and 1,4-dioxane.
[0017] Preferably, the drying temperature is 120°C and the drying time is 72 hours.
[0018] Preferably, the filtration and washing is performed using anhydrous ethanol.
[0019] Preferably, the purification process specifically involves: Soxhlet extraction with anhydrous ethanol until the effluent is colorless; and vacuum drying of the obtained solid product at 80°C for 24 hours to obtain the COF-TpBD / COF-TpMA composite photocatalyst.
[0020] The present invention also provides the application of the composite photocatalyst in the preparation of products that degrade tetracyclic antibiotics.
[0021] Preferably, the tetracycline antibiotics include tetracycline and oxytetracycline.
[0022] The present invention also provides a product for degrading tetracyclic antibiotics, comprising the composite photocatalyst.
[0023] The present invention also provides a method for degrading tetracyclic antibiotics, which utilizes the composite photocatalyst or the product to perform photocatalytic degradation of tetracyclic antibiotics in the aquatic environment.
[0024] Based on the above technical solution, the present invention has the following technical effects:
[0025] This invention prepares a composite catalyst COF-TpBD / COF-TpMA. The preparation method is simple, efficient, and easy to operate, and has practical application significance. This invention prepares a composite photocatalyst by in-situ growth of COF-TpMA on COF-TpBD, which can effectively promote charge separation, thereby significantly improving photocatalytic degradation performance. After 3 hours of xenon lamp irradiation (780nm > λ > 350nm), the degradation rate of oxytetracycline and tetracycline reaches 86%-87%, with maximum degradation rate constants of 1.0101 and 0.0115 min, respectively. -1 Furthermore, the composite catalyst COF-TpBD / COF-TpMA prepared in this invention exhibits excellent degradation stability. Attached Figure Description
[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0027] Figure 1 XRD patterns of COF-TpBD, COF-TpMA and 10wt% COF-TpBD / COF-TpMA;
[0028] Figure 2 Infrared spectra of COF-TpBD, COF-TpMA, and 10wt% COF-TpBD / COF-TpMA;
[0029] Figure 3 The UV-Vis absorption spectra of COF-TpBD, COF-TpMA, and COF-TpBD / COF-TpMA are shown; where a is the absorption spectrum and b is the band gap energy diagram.
[0030] Figure 4 Scanning electron microscope (SEM) and transmission electron microscope (TEM) images of COF-TpBD, COF-TpMA, and 10wt%-COF-TpBD / COF-TpMA are shown below. Specifically, a is the SEM image of COF-TpBD, b is the SEM image of COF-TpMA, c and d are the SEM images of 10wt%-COF-TpBD / COF-TpMA, and e and f are the TEM images of 10wt%-COF-TpBD / COF-TpMA.
[0031] Figure 5 Electrochemical impedance spectroscopy for COF-TpMA and COF-TpBD / COF-TpMA;
[0032] Figure 6The graphs show the degradation dynamics and kinetic linear simulation curves of tetracycline by COF-TpBD / COF-TpMA under visible light; where a is the degradation dynamics curve, b is the kinetic linear simulation curve, and c is the degradation rate comparison graph.
[0033] Figure 7 The graphs show the degradation dynamics and kinetic linear simulation curves of tetracycline by the composite photocatalyst COF-TpBD / COF-TpMA under the full light range; where a is the degradation dynamics curve, b is the kinetic linear simulation curve, and c is the degradation rate comparison graph.
[0034] Figure 8 The graph shows the degradation dynamics of oxytetracycline by the composite photocatalyst COF-TpBD / COF-TpMA under visible light; where a is the degradation dynamics of oxytetracycline by the composite photocatalyst COF-TpBD / COF-TpMA under visible light, b is the kinetic linear simulation curve, and c is the degradation rate comparison graph.
[0035] Figure 9 The graphs show the degradation dynamics and kinetic linear simulation curves of the composite photocatalyst COF-TpBD / COF-TpMA under the full light range for the photodegradation of oxytetracycline; where a is the degradation dynamics curve, b is the kinetic linear simulation curve, and c is the degradation rate comparison graph.
[0036] Figure 10 Comparison of photocatalytic degradation rates of 10wt% COF-TpBD / COF-TpMA composite catalysts after 3 cycles Detailed Implementation
[0037] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0038] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0039] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0040] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.
[0041] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0042] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.
[0043] Example 1
[0044] 1. Preparation of COF-TpBD / COF-TpMA composite photocatalyst
[0045] 1.1 COF-TpBD was prepared by a solvothermal method. 21 mg of trialdehyde-modified triphenol and 27.63 mg of benzidine were added to a mixture of 15 ml benzidine and 0.5 ml acetic acid and stirred for 5 h. The degassed dispersion was placed in a 120 °C oven and reacted for 72 h. After the oven temperature dropped to room temperature, the test tube was removed to obtain the crude reaction product. The crude reaction product was filtered and washed with anhydrous ethanol, dried at 80 °C for 12 h, and then naturally cooled to obtain a dark red powder.
[0046] 1.2 COF-TpBD (2.86 mg), 17.73 mg of trialdehyde-reactive triphenol, and 0.4 mL of 4 M acetic acid were mixed and dispersed in a mixed solution of 1.5 mL of mesitylene and 1.5 mL of 1,4-dioxane and sonicated (42 kHz) for 30 min. Then 8 mg of melamine was added and sonicated (42 kHz) for 1 h. The dispersion was transferred to a Parker tube and subjected to nitrogen purging and vacuuming, followed by freeze-thaw degassing, repeated three times. The degassed dispersion was placed in a 120°C oven for 72 hours. After the oven temperature dropped to room temperature, the test tube was removed to obtain a crude reaction product. The crude reaction product was filtered and washed with anhydrous ethanol and air-dried to obtain a brown solid product. The solid product was subjected to Soxhlet extraction with anhydrous ethanol until the effluent was colorless. The obtained solid product was vacuum dried at 100°C for 24 hours to obtain the COF-TpBD / COF-TpMA composite photocatalyst (10wt% COF-TpBD / COF-TpMA).
[0047] Comparative Example 1
[0048] The difference from Example 1 is that in step 1.2, the mass of COF-TpBD is 1.45 mg, and the remaining steps are the same as in Example 1, finally obtaining COF-TpBD / COF-TpMA composite photocatalyst (5 wt% COF-TpBD / COF-TpMA).
[0049] Comparative Example 2
[0050] The difference from Example 1 is that the mass of COF-TpBD in step 1.2 is 6.43 mg, and the rest of the steps are the same as in Example 1, finally obtaining COF-TpBD / COF-TpMA composite photocatalyst (20 wt% COF-TpBD / COF-TpMA).
[0051] Comparative Example 3
[0052] The difference from Example 1 is that in step 1.2, the mass of COF-TpBD is 11.03 mg, and the remaining steps are the same as in Example 1, finally obtaining COF-TpBD / COF-TpMA composite photocatalyst (30 wt% COF-TpBD / COF-TpMA).
[0053] Example 2
[0054] 1. XRD, infrared spectroscopy and electron microscopy were performed on Example 1; UV-Vis absorption spectroscopy and electrochemical impedance spectroscopy were performed on the COF-TpBD / COF-TpMA composite photocatalysts 5wt%-COF-TpBD / COF-TpMA, 10wt%-COF-TpBD / COF-TpMA, 20wt%-COF-TpBD / COF-TpMA and 30wt%-COF-TpBD / COF-TpMA prepared in Examples 1 and Comparative Examples 1-3.
[0055] 2. Photocatalytic performance test:
[0056] To investigate the photocatalytic activity of the samples, tetracycline and oxytetracycline were degraded under irradiation with a 300W xenon lamp (filter cutoff wavelength 420nm). 4 mg of the synthesized sample was added to 40 mL of a 10 mg / L tetracycline and oxytetracycline reaction solution. The solution was stirred in the dark for 30 min without adjusting the pH. After adsorption equilibrium was reached, the lamp was turned on, and samples were taken every 30 minutes. The concentration of tetracycline was determined using a UV-Vis spectrophotometer (UV-1200) system.
[0057] The formula for calculating pollutant removal rate is:
[0058] Removal rate (%) = (1-C) t / C0)×100%;
[0059] Among them, C t Let Ct be the pollutant concentration at time t, and C0 be the initial pollutant concentration.
[0060] 3. Results Analysis:
[0061] 3.1 XRD patterns of COF-TpBD, COF-TpMA, and 10wt% COF-TpBD / COF-TpMA are shown below. Figure 1 As shown in the figure, the (100), (110), and (310) crystal planes of COF-TpMA correspond to characteristic diffraction peaks at 6.1°, 11.5°, and 27°. The (100) and (110) crystal planes of COF-TpBD correspond to characteristic diffraction peaks at 6.2° and 11.5°. The 10wt% COF-TpBD / COF-TpMA exhibits diffraction peaks at 6.2°, 11.5°, and 27°, demonstrating the successful composite formation of COF-TpMA on COF-TpBD, thus preparing the COF-TpBD / COF-TpMA composite catalyst.
[0062] 3.2 Infrared spectra of COF-TpBD, COF-TpMA, and 10wt% COF-TpBD / COF-TpMA are shown below. Figure 2 As shown in the figure, 3403cm can be observed. -11618cm -1 1451cm -1 and 1294cm -1 The vibrational peaks at these locations correspond to NH, C=O, C=C, and CN in COF-TpBD, and to 3465 cm⁻¹ in COF-TpMA, respectively. -1 The vibrational peak of NH is 1384 cm⁻¹. -1 Corresponding to the CN vibration peak in the triazine ring, the 10wt%-COF-TpBD / COF-TpMA material showed vibration peaks of both COF-TpBD and COF-TpMA, and the vibration peak of NH was weakened, proving that the 10wt%-COF-TpBD / COF-TpMA was successfully prepared.
[0063] 3.3 UV-Vis absorption spectra of COF-TpBD, COF-TpMA, and COF-TpBD / COF-TpMA with different mass percentages are shown in the figure. Figure 3 As shown in the figure, COF-TpMA can absorb some visible light. The 10wt% COF-TpBD / COF-TpMA composite photocatalyst exhibits the mixed absorption characteristics of COF-TpBD and COF-TpMA, enhancing visible light absorption and broadening the visible light absorption range. Calculations show that the 10wt% COF-TpBD / COF-TpMA composite photocatalyst has a smaller band gap, meaning that the synthesized 10wt% COF-TpBD / COF-TpMA composite photocatalyst more effectively extends light absorption than pure COF-TpMA.
[0064] 3.4 Scanning electron microscope (SEM) and transmission electron microscope (TEM) images of COF-TpBD, COF-TpMA, and 10wt% COF-TpBD / COF-TpMA composite catalysts are shown below. Figure 4 As shown in the figure, (a) is a scanning electron microscope (SEM) image of COF-TpBD, (b) is a scanning electron microscope (SEM) image of COF-TpMA, (c)-(d) are SEM images of 10wt% COF-TpBD / COF-TpMA, and (e)-(f) are transmission electron microscope (TEM) images of 10wt% COF-TpBD / COF-TpMA. Figures (c)-(d) show that the rod-like structure of COF-TpMA is distributed on the sheet-like structure of COF-TpBD, demonstrating the successful composite of the two COFs and the morphological characteristics of the composite.
[0065] Electrochemical impedance spectroscopy (EI) plots for 3.5 COF-TpMA and COF-TpBD / COF-TpMA with different mass percentages are shown below. Figure 5As shown, compared with the COF-TpMA electrode, the 10wt%-COF-TpBD / COF-TpMA electrode has a smaller EIS curve radius, indicating that the formation of the heterojunction of the 10wt%-COF-TpBD / COF-TpMA composite photocatalyst can effectively enhance electronic conductivity and accelerate charge transfer, thereby improving photocatalytic performance.
[0066] 3.6 The degradation dynamics and kinetic linear simulation curves of tetracycline under visible light by the composite photocatalyst COF-TpBD / COF-TpMA are shown in the figure. Figure 6 As shown, the 10wt% COF-TpBD / COF-TpMA composite photocatalyst sample exhibited the highest photocatalytic activity, achieving a 73% degradation rate of tetracycline after 3 hours of xenon lamp irradiation (780nm > λ > 420nm), which is 1.79 times the degradation efficiency of pure COF-TpMA. Furthermore, by employing the first-order reaction kinetic equation ln(C... t The rate constant k can be obtained by fitting the tetracycline degradation kinetic curves of different samples with / C0)=kt. The maximum degradation rate constant of tetracycline on the 10wt% COF-TpBD / COF-TpMA sample is 0.007 min. -1 The efficiency is 1.3 times that of pure COF-TpMA. These results all indicate that the composite photocatalyst COF-TpBD / COF-TpMA effectively improves the photocatalytic degradation performance.
[0067] 3.7 The degradation dynamic curves and kinetic linear simulation curves of tetracycline by the composite photocatalyst COF-TpBD / COF-TpMA under the full light range are shown in the figure. Figure 7 As shown, the 10wt% COF-TpBD / COF-TpMA composite photocatalyst sample exhibited the highest photocatalytic activity. After 3.5 hours of xenon lamp irradiation (780nm > λ > 350nm), the degradation rate of tetracycline reached 87%, which was 1.17 times that of COF-TpMA, and the maximum degradation rate constant was 0.0115 min. -1 It is 1.61 times that of COF-TpMA.
[0068] 3.8 The degradation dynamics and kinetic linear simulation curves of oxytetracycline by the composite photocatalyst COF-TpBD / COF-TpMA under visible light (780nm>λ>420nm) are shown in the figure. Figure 8 As shown, the results indicate that the composite photocatalyst 10wt%-COF-TpBD / COF-TpMA did not significantly improve the maximum degradation rate of oxytetracycline, remaining at 60%, which is 1.04 times that of COF-TpMA. However, the maximum degradation rate constant was significantly improved, reaching 0.0057 min. -1 It is 1.26 times that of COF-TpMA.
[0069] 3.9 The degradation dynamic curves and kinetic linear simulation curves of the composite photocatalyst COF-TpBD / COF-TpMA under the full light range for the photodegradation of oxytetracycline are shown in the figure. Figure 9 As shown, the 10wt% COF-TpBD / COF-TpMA composite photocatalyst sample exhibited the highest photocatalytic activity. After 3.5 hours of xenon lamp irradiation (780nm > λ > 350nm), the degradation rate of tetracycline reached 86%, which was 1.02 times that of COF-TpMA, and the maximum degradation rate constant was 0.0101 min. -1 It is 1.04 times that of COF-TpMA.
[0070] 3.10 Comparison of photocatalytic degradation rates of 10wt% COF-TpBD / COF-TpMA composite catalysts after 3 cycles is shown in the figure below. Figure 9 As shown, the sample showed very little loss after three cycles, indicating that the composite catalyst COF-TpMA / COF-TpBD-10wt% prepared in this invention has excellent degradation stability.
[0071] In summary, this invention prepared a composite catalyst, 10 wt% COF-TpBD / COF-TpMA, using a simple, efficient, and easy-to-operate method with practical application significance. This invention prepares a composite photocatalyst by in-situ growth of COF-TpMA on COF-TpBD, which effectively promotes charge separation, thereby significantly improving photocatalytic degradation performance. After 3 hours of xenon lamp irradiation (780 nm > λ > 350 nm), the degradation rates of oxytetracycline and tetracycline reached 86%-87%, with maximum degradation rate constants of 1.0101 and 0.0115 min, respectively. -1 Furthermore, the composite catalyst 10wt%-COF-TpBD / COF-TpMA prepared in this invention exhibits excellent degradation stability.
[0072] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. A composite photocatalyst for the degradation of tetracyclic antibiotics, characterized in that, The composite photocatalyst is a COF-TpBD / COF-TpMA composite photocatalyst, and the preparation method of the composite photocatalyst includes the following steps: (1) COF-TpBD, trialdehyde-modified triphenol and acetic acid were dispersed in a mixed solution and sonicated, followed by the addition of melamine and sonication reaction; (2) After passing nitrogen gas through the dispersion obtained in step (1) and evacuating it, the dispersion is degassed and heated by freezing and thawing to obtain the crude product; (3) The crude product is filtered, washed and purified to obtain the composite photocatalyst.
2. The preparation method of the composite photocatalyst as described in claim 1, characterized in that, Includes the following steps: (1) COF-TpBD, trialdehyde-modified triphenol and acetic acid were dispersed in a mixed solution and sonicated, followed by the addition of melamine and sonication reaction; (2) After passing nitrogen gas through the dispersion obtained in step (1) and evacuating it, the dispersion is degassed and heated by freezing and thawing to obtain the crude product; (3) The crude product is filtered, washed and purified to obtain the composite photocatalyst.
3. The preparation method according to claim 2, characterized in that, The preparation method of COF-TpBD is as follows: trialdehyde-m-triphenol and benzidine are added to glycerol and stirred for 5 h, then nitrogen gas is purged and vacuum is applied, followed by heating for 72 h. The dispersion is washed with anhydrous ethanol and dried at 80°C for 12 h.
4. The preparation method according to claim 2, characterized in that, The ratio of COF-TpBD, trialdehyde-reactive triphenol, and acetic acid was 2.86 mg: 17.73 mg: 0.4ml。 5. The preparation method according to claim 4, characterized in that, The mass ratio of COF-TpBD to melamine is 2.86:
8.
6. The application of the composite photocatalyst as described in claim 1 in the preparation of products that degrade tetracyclic antibiotics.
7. The application according to claim 6, characterized in that, The tetracyclic antibiotics include tetracycline and oxytetracycline.
8. A product for degrading tetracyclic antibiotics, characterized in that, Includes the composite photocatalyst as described in claim 1.
9. A method for degrading tetracyclic antibiotics, characterized in that, The composite photocatalyst of claim 1 or the product of claim 8 is used to perform photocatalytic degradation of tetracyclic antibiotics in the aquatic environment.