Tetraazinyl covalent organic framework material, preparation method thereof and application of tetraazinyl covalent organic framework material in photocatalytic production of hydrogen peroxide
By modifying tetrazine by using the in-situ synthesis of COFs using the inverse Diels-Alder reaction to obtain the TP-EDDA-DMTZ photocatalyst, the existing photocatalysts have solved the problem of poor visible light absorption performance and low stability during catalytic hydrogen peroxide production, and efficient and stable hydrogen peroxide production is achieved.
Patent Information
- Application Number
- CN202510194028.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-21
- Publication Date
- 2025-05-27
AI Technical Summary
The existing photocatalysts have problems with poor visible light absorption performance and low stability when catalyzing hydrogen peroxide production, and the post-modification process of tetrazine-based covalent organic frame materials is complex and inefficient.
The tetrazine is modified during the in-situ synthesis of COFs by inverse Diels-Alder reaction (IEDDA) to obtain a TP-EDDA-DMTZ photocatalyst, which utilizes a covalent organic framework connected by imine bonds to improve photocatalytic activity.
The TP-EDDA-DMTZ photocatalyst significantly improves the catalytic hydrogen peroxide production activity under visible light, and the activity is increased by about 4.5 times. At the same time, the structure is stable, achieving low energy consumption, low cost and no secondary pollution.
Smart Images
Figure CN120037982A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of photocatalytic production of hydrogen peroxide, and relates to a method for producing hydrogen peroxide, specifically to a tetrazine-based covalent organic framework material, a preparation method thereof, and an application in photocatalytic production of hydrogen peroxide. Background Art
[0002] Hydrogen peroxide is a high-value and multifunctional chemical, which is widely used in fields such as wastewater treatment, chemical synthesis, medical disinfection, and clean energy, and has attracted much attention due to its environmentally friendly characteristics. Currently, hydrogen peroxide is mainly produced industrially by the anthraquinone oxidation method, but this process has problems such as high energy consumption, complex process, and accompanied by the emission of harmful wastes. Therefore, it is of great significance to develop a greener and lower-energy production method. The photocatalytic synthesis of hydrogen peroxide from water and oxygen using semiconductor photocatalysts shows the potential to replace the traditional anthraquinone process due to its low energy consumption, pollution-free, and high safety characteristics. Although inorganic semiconductor photocatalysts such as TiO 2 , ZnO, and BiVO 4 exhibit certain ability for photocatalytic preparation of hydrogen peroxide, they generally have the disadvantages of poor visible light absorption performance and low stability. In recent years, the rise of organic semiconductor photocatalysts has brought new opportunities to this field, including materials such as polymeric carbon nitride, covalent triazine frameworks, and covalent organic frameworks (COFs). Compared with inorganic materials, organic semiconductor materials have advantages such as multifunctionality, rich active sites, and environmental friendliness, thus attracting extensive attention. Among them, covalent organic framework materials are considered to be promising photocatalysts in the field of chemical transformation due to their highly tunable structure, rich active sites, and porous characteristics. Tetrazine has attracted much attention due to its strong electron-withdrawing ability, excellent chemical and thermal stability, promotion of π-π stacking, and formation of porous structures. However, there are certain limitations in the post-modification process of tetrazine, such as complex process, low efficiency, possible destruction of the original structure of COFs, and simultaneous reduction of the chemical activity of COFs, thus limiting its application in COF modification. How to develop tetrazine-modified COF materials with high activity and good stability has become the focus of current research. Through exploring various modification methods, tetrazine-modified COFs have shown broad application prospects in the catalytic field. Summary of the Invention
[0003] The object of the present invention is to overcome the deficiencies of the current technology and provide a method for producing a novel covalent organic framework photocatalyst for hydrogen peroxide production by modifying tetrazine using the inverse Diels-Alder reaction (IEDDA) during the in-situ synthesis of COFs.
[0004] To achieve the above object, the technical solution adopted by the present invention is: a tetrazine-based covalent organic framework material TP-EDDA-DMTZ photocatalyst, and the TP-EDDA-DMTZ photocatalyst is a covalent organic framework connected by imine bonds.
[0005] The preparation method of the above-mentioned tetrazine-based covalent organic framework material TP-EDDA-DMTZ photocatalyst includes the following steps:
[0006] 1) Add an appropriate amount of phloroglucinol trialdehyde TP, bis(4-aminophenyl)acetylene EDDA, and dimethyl-1,2,4,5-tetrazine DMTZ to a mortar and grind them.
[0007] 2) For the ground solid, add N,N-dimethylformamide DMF and acetic acid for solvothermal reaction, centrifuge the resulting reactant, wash the obtained solid with acetone and tetrahydrofuran, and dry it under vacuum to obtain the target product.
[0008] In the above preparation method, the molar ratio of TP, EDDA, and DMTZ in step 1) is 1:1.5:2.25.
[0009] In the above preparation method, in step 2), the volume ratio of the DMF solution of the covalent organic framework connected by imine bonds to acetic acid is 1:0.1, and the concentration of acetic acid is 3M.
[0010] In the above preparation method, in step 2), the solvothermal reaction is carried out at 120 °C for 72 h.
[0011] The above-mentioned TP-EDDA-DMTZ photocatalyst is used in the photocatalytic production of hydrogen peroxide from water.
[0012] The above application includes the following steps: Mix the above-mentioned TP-EDDA-DMTZ photocatalyst with ultrapure water and carry out photocatalytic reaction under visible light irradiation conditions to complete the production of hydrogen peroxide.
[0013] In the above application, the above-mentioned TP-EDDA-DMTZ photocatalyst: ultrapure water = 1 mg: 3 mL.
[0014] In the above application, during the photocatalytic reaction process, oxygen is also introduced into the reaction system; the photocatalytic reaction time is 30 min to 120 min, and the supernatant in the reaction pool is filtered to obtain a hydrogen peroxide solution and a photocatalytic material.
[0015] In the above application, the filter membrane material used for filtration is a hydrophilic polyethersulfone filter membrane; the pore size of the hydrophilic polyethersulfone filter membrane is 0.22 μm to 0.45 μm.
[0016] The beneficial effects of the present invention are as follows: The present invention uses in-situ synthesis method to modify the trialdehyde phloroglucinol-bis(4-aminophenyl)acetylene covalent organic framework (TP-EDDA) photocatalyst. Using DMTZ as the modifying molecule, the modified TP-EDDA-DMTZ photocatalyst is obtained by a one-pot method. This catalyst can efficiently catalyze the production of hydrogen peroxide under visible light. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 is the powder X-ray diffraction pattern of the TP-EDDA-DMTZ photocatalyst.
[0018] Figure 2 are the scanning electron microscope images (a), (b) of the TP-EDDA-DMTZ photocatalyst.
[0019] Figure 3 is the comparison chart of hydrogen peroxide production catalyzed by the TP-EDDA photocatalyst and the TP-EDDA-DMTZ photocatalyst under visible light (λ≥420nm). DETAILED DESCRIPTION OF THE INVENTION
[0020] Example 1
[0021] (I) Preparation of the TP-EDDA-DMTZ photocatalyst:
[0022] 21 mg of TP, 31 mg of EDDA and 25 mg of DMTZ were ground and dissolved in a pyrex tube containing 1 mL of DMF solution, and ultrasonicated for 20 min. Then, 100 μL of 3M acetic acid was added, sealed, and left standing at 120 °C for 72 h. The product was centrifuged, washed repeatedly with acetone and tetrahydrofuran, and finally dried in vacuo at 60 °C for 12 h to obtain the TP-EDDA-DMTZ photocatalyst. (II) Preparation of the TP-EDDA photocatalyst
[0023] 21 mg of TP and 31 mg of EDDA were dissolved in a pyrex tube containing 1 mL of DMF solution, and ultrasonicated for 20 min. Then, 100 μL of 3M acetic acid was added, sealed, and left standing at 120 °C for 72 h. The product was centrifuged, washed repeatedly with acetone and tetrahydrofuran, and finally dried in vacuo at 60 °C for 12 h to obtain the TP-EDDA photocatalyst.
[0024] (III) Test results
[0025] Figure 1 is the powder X-ray diffraction pattern of the TP-EDDA-DMTZ photocatalyst. It can be seen from Figure 1 that the covalent organic framework material of the TP-EDDA-DMTZ photocatalytic hydrogen peroxide production has good crystallinity.
[0026] Figure 2These are the scanning electron microscope images (a) and (b) of the TP-EDDA-DMTZ photocatalyst. From Figure 2 It can be seen from (a) and (b) that the TP-EDDA-DMTZ photocatalyst is a structure formed by linear coiling.
[0027] Example 2 Production of hydrogen peroxide catalyzed by the TP-EDDA-DMTZ photocatalyst
[0028] The method is as follows: The reaction is carried out in a quartz reactor, and a 300W xenon lamp is used as a light source to simulate sunlight. The catalyst TP-EDDA-DMTZ (5mg) is ultrasonically dispersed in 15mL of ultrapure water, and high-purity oxygen is introduced into the reaction system for 30 minutes, and then the reaction is carried out under visible light (λ≥420nm) irradiation for 2h. During the reaction, the supernatant is taken out from the quartz reactor every 30 minutes, and the supernatant in the reaction pool is filtered to obtain a hydrogen peroxide solution and a photocatalytic material. The filter membrane material used for filtration is a hydrophilic polyethersulfone filter membrane; the pore size of the hydrophilic polyethersulfone filter membrane is 0.22μm - 0.45μm. Ammonium molybdate and potassium iodide are added for color development, and the amount of hydrogen peroxide generated is detected every 30 minutes using an ultraviolet spectrophotometer. In the reference experiment, TP-EDDA is used as the catalyst respectively.
[0029] The experimental results are as Figure 3 When TP-EDDA is used as the catalyst, the amount of hydrogen peroxide produced in 2h is 0.56mmol·g -1 ; while when the TP-EDDA-DMTZ photocatalyst is used as the catalyst, the catalytic activity is significantly improved, and the amount of hydrogen peroxide produced increases with the increase of the reaction time. The total amount of hydrogen peroxide produced in 2h reaches 2.552mmol·g -1 . It can be seen that when DMTZ combines with TP-EDDA to form a covalent organic framework photocatalyst, the separation efficiency of its electron-hole pairs is improved and the photocatalytic activity is enhanced, making the hydrogen peroxide production activity of TP-EDDA-DMTZ about 4.5 times higher than that of TP-EDDA. The TP-EDDA-DMTZ photocatalyst has high catalytic activity and stable structure. It is a photocatalyst that can efficiently produce hydrogen peroxide under visible light conditions without a hole sacrificial agent, with the significant advantages of low energy consumption, low cost, and no secondary pollution, and has good application prospects in the field of photocatalytic hydrogen peroxide production.
Claims
1. A tetrazine-based covalent organic framework material TP-EDDA-DMTZ photocatalyst, characterized in that: The TP-EDDA-DMTZ photocatalyst is a covalent organic framework connected by imine bonds.
2. The method for preparing a tetrazine-based covalent organic framework material TP-EDDA-DMTZ photocatalyst according to claim 1, characterized in that: The steps include: 1) adding appropriate amounts of trialdehyde phloroglucinol TP, bis(4-aminophenyl)acetylene EDDA and dimethyl-1,2,4,5-tetrazine DMTZ into a mortar and grinding; 2) Add N,N-dimethylformamide (DMF) and acetic acid to the ground solid for solvothermal reaction. Centrifuge the resulting reactant. Wash the resulting solid with acetone and tetrahydrofuran and dry in vacuo to obtain the target product.
3. The preparation method according to claim 2, characterized in that: The molar ratio of TP, EDDA and DMTZ in step 1) is 1:1.5:2.
25.
4. The preparation method according to claim 2, characterized in that: In step 2), the volume ratio of the DMF solution of the imine bond-connected covalent organic framework to acetic acid is 1:0.1, and the concentration of acetic acid is 3M.
5. The preparation method according to claim 2, characterized in that: In step 2), the solvent thermal reaction is carried out at 120° C. for 72 hours.
6. Use of the TP-EDDA-DMTZ photocatalyst according to claim 1 in photocatalytic water production of hydrogen peroxide.
7. The use according to claim 6, characterized in that: The method comprises the following steps: mixing the TP-EDDA-DMTZ photocatalyst described in claim 1 with ultrapure water, carrying out a photocatalytic reaction under visible light conditions, and completing the production of hydrogen peroxide.
8. The use according to claim 7, characterized in that: The TP-EDDA-DMTZ photocatalyst according to claim 1: ultrapure water = 1 mg: 3 mL.
9. The use according to claim 7, characterized in that: The photocatalytic reaction process also includes oxygenating the reaction system; the photocatalytic reaction time is 30 minutes to 120 minutes, and the supernatant in the reaction tank is filtered to obtain a hydrogen peroxide solution and a photocatalytic material.
10. The use according to claim 8, characterized in that: The filter membrane material used for filtration is a water-based polyethersulfone filter membrane; the pore size of the water-based polyethersulfone filter membrane is 0.22 μm to 0.45 μm.