Synthesis method and application of D-A-A motif cation edge engineering 1D sp2 carbon conjugated covalent organic framework

Abstract

The invention discloses a synthesis method and application of a D-A-A motif cation edge engineering 1D sp2 carbon conjugated covalent organic framework, and belongs to the technical field of adsorption material synthesis, and the synthesis method comprises the following steps: S1, preparing a reaction mixed solution I; s2, preparing a uniform mixed solution I; s3, preparing a product mixed solution I; s4, preparing a 1D sp2 carbon conjugate covalent organic framework of a D-A-A motif; s5, preparing a reaction mixed solution II; s6, preparing a product mixed solution II; s7, preparing a cation edge engineering 1D sp2 carbon conjugated covalent organic framework of a D-A-A motif; the synthesized D-A-A motif cation edge engineering 1D sp2 carbon conjugated covalent organic framework is simple in method, stable in structure and environment-friendly, and has efficient light collection performance and spatially resolved active sites, so that efficient charge separation / transmission is achieved, the reaction efficiency and optical activity can be improved, and the application prospect is wide. Therefore, the ultrafast removal of bisphenol A and chloropalladate ions is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of synthesis of adsorption materials, and specifically relates to a synthesis method and application of a cationic edge engineering 1D sp 2 carbon-conjugated covalent organic framework with a D-A-A motif. Background Art

[0002] Bisphenol A is an important raw material for manufacturing products such as epoxy resins, polycarbonates, polysulfones, polyarylate, and phenolic resins. However, due to its environmental persistence and bioaccumulation, it has posed a serious threat to the global water-soil ecosystem.

[0003] Currently, the methods for treating bisphenol A include adsorption, biological treatment, and photocatalytic degradation. Among them, the adsorption method is widely used due to its simple operation and environmental friendliness.

[0004] The adsorbents used in the current adsorption method include activated carbon, MOFs, carbon nanotubes, graphene oxide, and photocatalysts, etc. Among them, covalent organic frameworks are widely used due to their customizable pore structures and functional groups. However, the current applications of covalent organic frameworks still have the following problems: the interlayer π-π stacking of traditional two-dimensional covalent organic frameworks results in more than 90% of the active sites being buried in the basal plane, with low interfacial charge transfer efficiency. Although one-dimensional covalent organic frameworks are rich in edge active sites, their short-range π conjugation (<5 nm) leads to ultrafast charge recombination (τ < 1 ps), with a photon utilization rate of less than 5%, resulting in low removal efficiency of bisphenol A. At the same time, most of them focus on removing single pollutants and it is difficult to synchronously recover strategic metals including palladium in wastewater.

[0005] In view of this, a synthesis method and application of a cationic edge engineering 1D sp 2 carbon-conjugated covalent organic framework with a D-A-A motif are designed to solve the above problems. Summary of the Invention

[0006] To solve the problems raised in the above background art, the present invention provides a synthesis method and application of a cationic edge engineering 1D sp 2 carbon-conjugated covalent organic framework with a D-A-A motif, which has high π-conjugation and fast charge separation / transport, and realizes the characteristics of ultrafast removal of bisphenol A and chloropalladate ions.

[0007] Another object of the present invention is to provide an application of a synthesis method of a cationic edge engineering 1D sp 2 carbon-conjugated covalent organic framework with a D-A-A motif.

[0008] To achieve the above object, the present invention provides the following technical solution: A cationic edge engineering 1Dsp 2Synthesis method of carbon-conjugated covalent organic framework, comprising the following steps:

[0009] S1: Using Ir(ppy)2(CHO)2, 2,2',2”,2”'-(pyrene-1,3,6,8-tetrayltetra(benzene-4,1-diyl))tetraacetonitrile and 5,5'-diamino-2,2'-bipyridine as reaction monomers, adding 1,4-dioxane and potassium hydroxide thereto, and performing ultrasonic treatment to obtain reaction mixture 1;

[0010] S2: Loading reaction mixture 1 into a quartz tube, placing the quartz tube containing reaction mixture 1 in a liquid nitrogen bath for cooling, then removing the gas through three freeze-pump-thaw cycles and flame-sealing, and performing ultrasonic treatment to obtain homogeneous mixture 1;

[0011] S3: Stirring homogeneous mixture 1 at 110 °C for 3 d to obtain product mixture 1;

[0012] S4: Centrifuging product mixture 1 to separate out the solid, washing the solid and performing vacuum drying, to obtain a 1D sp of D-A-A motif 2 carbon-conjugated covalent organic framework;

[0013] S5: Adding the 1D sp 2 carbon-conjugated covalent organic framework of D-A-A motif to 1,2-dibromoethane and acetonitrile to obtain reaction mixture 2;

[0014] S6: Under nitrogen protection, heating reaction mixture 2 under reflux at 82 °C for 24 h to obtain product mixture 2;

[0015] S7: Centrifuging product mixture 2 to separate out the solid, washing the solid and performing vacuum drying, to obtain a cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework of D-A-A motif.

[0016] Further, in step S1, the molar ratio of addition of Ir(ppy)2(CHO)2, 2,2',2”,2”'-(pyrene-1,3,6,8-tetrayltetra(benzene-4,1-diyl))tetraacetonitrile and 5,5'-diamino-2,2'-bipyridine is 3:5:7.

[0017] Further, in step S1, the addition amount of 1,4-dioxane is 1-3 mL.

[0018] Further, in step S4, the solid is washed successively with tetrahydrofuran and acetone. <tmp

[0019] Further, in step S5, the addition amount of 1,2-dibromoethane is 2-10 mL, and the addition amount of acetonitrile is 30-50 mL.

[0020] Further, in the step S7, the solid is washed with ether.

[0021] Synthesis method of a cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework synthesized by the synthesis method of a cationic edge-engineered 1D sp 2 Application of the carbon-conjugated covalent organic framework in degrading bisphenol A and photocatalytically removing chloropalladate ions.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] The method for synthesizing the cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework of the present invention is simple, has a stable structure and is environmentally friendly. At the same time, it has high-efficiency light collection performance and spatially resolved active sites, so it has efficient charge separation / transport, thereby improving optical activity and photocatalytic reaction efficiency, and thus realizing the ultrafast removal of bisphenol A and chloropalladate ions. Description of the Drawings

[0024] Figure 1 Synthesis schematic diagram of the present invention;

[0025] Figure 2 Infrared spectrum of the embodiment of the present invention;

[0026] Figure 3 Infrared spectrum of the embodiment of the present invention.

[0027] Figure 4 XRD pattern of the embodiment of the present invention.

[0028] Figure 5 UV-visible absorption spectrum of the embodiment of the present invention.

[0029] <C Figure 6 Transient photocurrent response diagram of the embodiment of the present invention.

[0030] Figure 7 Adsorption isotherm diagram of the embodiment of the present invention for palladium(II).

[0031] Figure 8 Adsorption kinetics diagram of the embodiment of the present invention for palladium(II).

[0032] Figure 9 Adsorption kinetics diagram of the embodiment of the present invention for bisphenol A. Detailed Embodiments

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] The present invention provides the following technical solution: A synthesis method of a cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework, comprising the following steps:

[0035] S1: Using Ir(ppy)2(CHO)2, 2,2',2”,2”'-(pyrene-1,3,6,8-tetrayltetra(benzene-4,1-diyl))tetraacetonitrile and 5,5'-diamino-2,2'-bipyridine as reaction monomers, adding 1,4-dioxane and potassium hydroxide thereto, and performing ultrasonic treatment to obtain a first reaction mixture;

[0036] S2: Loading the first reaction mixture into a quartz tube, cooling the quartz tube containing the first reaction mixture in a liquid nitrogen bath, and then removing the gas through three freeze-pump-thaw cycles and flame-sealing it, and performing ultrasonic treatment to obtain a first homogeneous mixture;

[0037] S3: Stirring the first homogeneous mixture at 110 °C for 3 days to obtain a first product mixture;

[0038] S4: Centrifuging the first product mixture to separate the solid, washing the solid and performing vacuum drying to obtain a 1D sp 2 carbon-conjugated covalent organic framework with a D-A-A motif;

[0039] S5: Adding the 1D sp 2 carbon-conjugated covalent organic framework with a D-A-A motif to 1,2-dibromoethane and acetonitrile to obtain a second reaction mixture;

[0040] S6: Under nitrogen protection, heating and refluxing the second reaction mixture at 82 °C for 24 h to obtain a second product mixture;

[0041] S7: Centrifuging the second product mixture to separate the solid, washing the solid and performing vacuum drying to obtain a cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework with a D-A-A motif.

[0042] Specifically, in step S1, the molar ratio of Ir(ppy)2(CHO)2, 2,2',2”,2”'-(pyrene-1,3,6,8-tetrayltetra(benzene-4,1-diyl))tetraacetonitrile, and 5,5'-diamino-2,2'-bipyridine is 3:5:7.

[0043] Specifically, in step S1, the addition amount of 1,4-dioxane is 1 - 3 mL.

[0044] Specifically, in step S4, the solid is washed successively with tetrahydrofuran and acetone.

[0045] Specifically, in step S5, the addition amount of 1,2-dibromoethane is 2 - 10 mL, and the addition amount of acetonitrile is 30 - 50 mL.

[0046] Specifically, in step S7, the solid is washed with ether.

[0047] Example 1

[0048] As shown in the appendix Figure 1 8.56 mg (0.012 mmol) of Ir(ppy)2(CHO)2, 13.25 mg (0.02 mmol) of 2,2',2”,2”'-(pyrene-1,3,6,8-tetrayltetra(benzene-4,1-diyl))tetraacetonitrile (PyTT-CN), and 5.94 mg (0.028 mmol) of 5,5'-diamino-2,2'-bipyridine (BpyA) are used as reaction monomers. 2.0 mL of 1,4-dioxane and 0.1 mL (4 mol / L -1 ) of potassium hydroxide are added thereto, and the mixture is ultrasonically treated to obtain reaction mixture 1;

[0049] Reaction mixture 1 is placed in a 10 mL quartz tube. The quartz tube containing reaction mixture 1 is cooled in a liquid nitrogen bath, and then the gas is removed by three freeze-pump-thaw cycles and flame-sealed, and ultrasonically treated to obtain homogeneous mixture 1;

[0050] Homogeneous mixture 1 is stirred at 110 °C for 3 days to obtain product mixture 1;

[0051] The solid is separated from product mixture 1 by centrifugation, washed, and vacuum-dried to obtain a 1D sp 2 carbon-conjugated covalent organic framework Ole Ir-COF with a D-A-A motif;

[0052] The 1D sp 2 carbon-conjugated covalent organic framework with a D-A-A motif is added to 5.0 mL of 1,2-dibromoethane and 45.0 mL of acetonitrile to obtain reaction mixture 2;

[0053] Under nitrogen protection, the reaction mixture II was heated under reflux at 82 °C for 24 h to obtain the product mixture II;

[0054] The product mixture II was centrifuged to separate the solid, and after washing and vacuum drying the solid, the cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework Ole Ir-COF 2+ was obtained;

[0055] Ir(ppy)2(CHO)2, 2,2',2”,2”'-(pyrene-1,3,6,8-tetrayltetra(benzene-4,1-diyl))tetraacetonitrile (PyTT-CN) and 5,5'-diamino-2,2'-bipyridine (BpyA) were characterized by infrared spectroscopy, and the results are as shown in the appendix Figure 2 as follows;

[0056] The 1D sp 2 carbon-conjugated covalent organic framework Ole Ir-COF with D-A-A motif and the cationic edge-engineered 1D sp2 carbon-conjugated covalent organic framework Ole Ir-COF with D-A-A motif 2+ were characterized, as shown in the appendix Figure 3 as follows;

[0057] Ir(ppy)2(CHO)2, 2,2',2”,2”'-(pyrene-1,3,6,8-tetrayltetra(benzene-4,1-diyl))tetraacetonitrile (PyTT-CN), 5,5'-diamino-2,2'-bipyridine (BpyA) and the 1D sp 2 carbon-conjugated covalent organic framework Ole Ir-COF with D-A-A motif 2+ were characterized by X-ray diffraction (XRD), and the results are as shown in the appendix Figure 4 as follows, indicating good crystallinity;

[0058] The optoelectronic properties of the cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework Ole Ir-COF 2+ were detected by ultraviolet-visible absorption spectroscopy and transient photocurrent response spectra, and the results are as shown in the appendix Figure 5 and 6 as follows.

[0059] Example 2

[0060] Application of the cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework in the degradation of bisphenol A:

[0061] A solution to be treated of bisphenol A with an ion concentration of 50 mg / L was prepared;

[0062] The pH value of the solution to be treated containing bisphenol A is adjusted to 2 - 13 with a pH regulator, and 5 is selected in this example;

[0063] 0.1 - 1.0 g / L of the cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework is added to the solution to be treated containing bisphenol A, and 0.2 g / L is selected in this example, to obtain a suspension;

[0064] The adsorbed suspension is filtered through a 0.22 μm nylon membrane filter.

[0065] Example Three

[0066] Application of the cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework with D - A - A motif in photocatalytic removal of chloropalladate ions:

[0067] Prepare a solution to be treated containing palladium(II) with a palladium content of 1000 ppm;

[0068] The pH value of the solution to be treated containing palladium(II) is adjusted to 2 - 6 with a pH regulator, and 5 is selected in this example;

[0069] Under light illumination, 0.0625 - 0.375 g / L of the cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework with D - A - A motif is added to the solution to be treated containing palladium(II), and 0.2 g / L is selected in this example, to obtain a suspension, and the soluble palladium(II) in the suspension is reduced to insoluble palladium(0);

[0070] The adsorbed suspension is filtered through a 0.22 μm microporous membrane filter.

[0071] Ole Ir-COF 2+ The adsorption isotherm of PdCl4 - is as shown in the appendix Figure 7 and the results show that under light illumination, OleIr-COF 2+ has an adsorption capacity of 1778 mg / g for PdCl4 - (1000 mg / L), which is due to the defect-tolerant exciton migration path and spatially orthogonal functional domains of OleIr-COF 2+ , thus greatly improving the utilization efficiency of photo-generated charges and significantly enhancing the adsorption capacity for PdCl4 - ;

[0072] Ole Ir-COF 2+ for PdCl4- The adsorption kinetics of Figure 8 is shown as follows. The results show that Ole Ir-COF 2+ reaches dynamic equilibrium for the adsorption of PdCl4 - within 30 min in the dark, and 95% of PdCl4 can be removed within 80 min under light illumination. - This is because Ole Ir-COF 2+ has the characteristics of a strong built-in electric field of the D-A-A type and cascaded energy transfer, thus promoting the rapid separation / transport of electrons and holes, and thus greatly improving the degradation efficiency of PdCl4. - ;

[0073] The removal kinetics of bisphenol A by Ole Ir-COF 2+ is shown as follows. The results show that in the absence of a photocatalyst, the concentration of bisphenol A remains basically unchanged. Secondly, when only Ole Ir-COF Figure 9 is added, the adsorption of bisphenol A reaches dynamic equilibrium within 30 min in the dark, and 64% of bisphenol A can be removed within 60 min under light illumination. Furthermore, when palladium(II) is added, Ole Ir-COF 2+ can promote the removal of bisphenol A (the removal rate is increased by 24%). This is because the cationic edge-functionalized Ole Ir-COF 2+ has spatially orthogonal functional domains, and the quaternary ammonium group realizes strong chemical adsorption of PdCl4 2+ through ion exchange and is rapidly reduced to insoluble palladium(0) by photogenerated electrons here. The terminal of the electron-deficient iridium complex can serve as a hole reservoir for the oxidation of bisphenol A, thus greatly improving the degradation efficiency of bisphenol A. - ;

[0074] In summary, the present application has excellent photocatalytic performance, can efficiently remove palladium(II) and rapidly degrade bisphenol A, and can be used as a multifunctional catalyst for complex reaction cascades.

[0075] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made in these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A synthetic method of a cationic edge-engineering 1D sp 2 carbon-conjugated covalent organic framework with a D-A-A motif, characterized in that It includes the following steps: S1: Using Ir(ppy)2(CHO)2, 2,2',2”,2”'-(pyrene-1,3,6,8-tetrayltetra(benzene-4,1-diyl))tetraacetonitrile and 5,5'-diamino-2,2'-bipyridine as reaction monomers, adding 1,4-dioxane and potassium hydroxide thereto, and performing ultrasonic treatment to obtain a first reaction mixture; S2: Loading the first reaction mixture into a quartz tube, placing the quartz tube containing the first reaction mixture in a liquid nitrogen bath for cooling, then removing the gas through three freeze-pump-thaw cycles and flame-sealing, and performing ultrasonic treatment to obtain a first homogeneous mixture; S3: Stirring the first homogeneous mixture at 110 °C for 3 d to obtain a first product mixture; S4: Centrifuge the product mixture I to separate the solid. After washing and vacuum drying the solid, 1D sp of the D-A-A motif is obtained. 2 carbon-conjugated covalent organic framework; S5: Add the 1D sp 2 carbon-conjugated covalent organic framework to 1,2-dibromoethane and acetonitrile to obtain reaction mixture two; S6: Under nitrogen protection, heating and refluxing the second reaction mixture at 82 °C for 24 h to obtain a second product mixture; S7: Centrifuge the product mixture II to separate the solid. After washing and vacuum drying the solid, a cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework is obtained.

2. A method for synthesizing a cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework with a D-A-A motif, characterized in that: In the step S1, the molar ratio of the addition of Ir(ppy)2(CHO)2, 2,2',2”,2”'-(pyrene-1,3,6,8-tetrayltetra(benzene-4,1-diyl))tetraacetonitrile and 5,5'-diamino-2,2'-bipyridine is 3:5:

7.

3. A method for synthesizing a cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework with a D-A-A motif according to claim 2, characterized in that: In the step S1, the addition amount of 1,4-dioxane is 1 - 3 mL.

4. A method for synthesizing a cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework based on the D-A-A motif according to claim 3, characterized in that: In the step S4, the solid is washed successively with tetrahydrofuran and acetone.

5. A method for synthesizing a cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework of the D-A-A motif according to claim 4, characterized in that: In the step S5, the addition amount of 1,2-dibromoethane is 2 - 10 mL, and the addition amount of acetonitrile is 30 - 50 mL.

6. A method for synthesizing a cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework according to claim 5, characterized in that: In the step S7, the solid is washed with ether.

7. A method for synthesizing a cationic edge-engineered 1D sp D-A-A motif 2 carbon-conjugated covalent organic framework, and the application of the cationic edge-engineered 1D sp 2 carbon-conjugated covalent organic framework in the degradation of bisphenol A and the photocatalytic removal of chloropalladate ions.

Images