Coordination polymer containing substituted polyacid and naphthalimide as well as preparation method and application of coordination polymer
A coordination polymer of substituted polyoxometalate and naphthalimide forms a stable, efficient visible light catalyst for degrading carcinogenic dyes, addressing the limitations of inorganic catalysts by enhancing electron transfer and stability.
Patent Information
- Application Number
- CN202510468200.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-15
- Publication Date
- 2025-07-15
AI Technical Summary
The existing inorganic photocatalysts can only absorb ultraviolet light and part of visible light due to their wide band gap, which limits their application in visible light catalytic degradation dyes. It is still difficult to develop coordination polymer photocatalysts with good stability, cheap and easy to obtain and high catalytic activity.
Coordinating polymers containing substituted polyacids and naphthalene diimides are designed to form a two-dimensional metal organic framework material by coordination of N,N’-di((4-N”-oxypyridinyl)methyl)-1,4,5,8-naphthalene diimide, phosphomolybdate ions and europium ions as photocatalysts for degradation of organic carcinogenic contaminants.
It provides efficient visible light catalytic efficiency, excellent thermal stability and catalytic stability, and can efficiently degrade alkaline red 9 and methyl blue, which is suitable for the removal of environmental pollutants.
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Figure CN120309957A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of the preparation of photocatalytic materials, and particularly relates to a coordination polymer containing substituted polyoxoacid and naphthalenediimide, a preparation method thereof, and an application thereof. Background Art
[0002] With the continuous development of society, dyes have been widely used in many fields of industry. However, some dyes have been proven to seriously damage the environment and endanger biological health, such as basic red 9, basic violet 14, etc. Therefore, the development of materials that can effectively remove carcinogenic dye pollutants has received extensive attention in the fields of environmental science, medical science, and life science. Photocatalysis is an important basic process for degrading organic pollutants, decomposing water, and converting CO2. In the past few decades, the development of new photocatalysts to solve water pollution problems has been continuously studied. For the photocatalytic degradation of organic pollutants, the core lies in the formation of a stable charge separation state in the catalyst, thereby promoting the photoinduced electron transfer reaction. For a long time, the research of photocatalysts has mainly focused on inorganic compounds. However, due to the relatively wide band gap of inorganic photocatalysts, they can only absorb ultraviolet light and part of visible light, which greatly limits their application in the visible light catalytic degradation of dyes. Since the energy level difference between organic and inorganic components usually causes photoinduced electron transfer between components, hybrid materials or coordination polymers based on organic and inorganic components can, in principle, become ideal photocatalysts for degrading organic pollutants through photoinduced electron transfer reactions. However, how to select appropriate inorganic and organic components and assemble them into hybrid materials remains a major challenge.
[0003] To address this challenge, researchers have proposed various methods for constructing photoinduced electron transfer-type inorganic-organic hybrid materials or coordination polymers. One strategy is to introduce polyoxometalates (abbreviated as polyoxoacids), which have oxidative activity, into photoactive coordination polymers. Polyoxoacids can form mixed-valence species with reducing activity through chemical reduction, thereby constructing a charge separation state for the selective oxidation of substrates. In terms of organic ligands, more and more scientific researchers have focused on electron-deficient organic molecules with an extended π-conjugated plane because the coordination polymers formed by such molecules have unique performance advantages such as a wide variety, rich structure, regular pore structure, and adjustable pore size. Moreover, coordination polymers based on electron-deficient large π-conjugated molecules have strong visible light absorption, tunable optoelectronic properties, multiple active sites, etc. In recent years, in addition to having broad application scenarios in chemical sensing, lithium-ion batteries, solar cells, etc., their application potential in photocatalysis has also been explored. However, there are still many difficulties in developing coordination polymer photocatalysts with good stability, low cost, high catalytic activity, and visible light response. Summary of the Invention
[0004] The object of the present invention is to provide a coordination polymer containing substituted polyacid and naphthalenediimide, a preparation method thereof and an application thereof. By designing a coordination polymer containing substituted polyacid and naphthalenediimide and using it as a photocatalyst, the organic carcinogenic pollutants Basic Red 9 and Methyl Blue in water can be photocatalytically degraded efficiently. The provided coordination polymer containing substituted polyacid and naphthalenediimide has excellent thermal stability, catalytic stability and visible light photocatalytic efficiency.
[0005] To achieve the above object, the present invention provides the following technical solutions:
[0006] One of the technical solutions of the present invention: Provide a coordination polymer containing substituted polyacid and naphthalenediimide, and the coordination polymer containing substituted polyacid and naphthalenediimide is a two-dimensional metal-organic framework material formed by the coordination of the nitrogen oxide on N,N'-bis((4-N"-oxypyridinyl)methyl)-1,4,5,8-naphthalenediimide, phosphomolybdate ions and europium ions; the coordination polymer containing substituted polyacid and naphthalenediimide belongs to the triclinic system, space group P-1, and the unit cell parameters α = 83.489(5)°, β = 84.170(4)°, γ = 87.570(4)°.
[0007] Another technical solution of the present invention: Provide a preparation method of the above coordination polymer containing substituted polyacid and naphthalenediimide, including the following steps:
[0008] Dissolve N,N'-bis((4-N"-oxypyridinyl)methyl)-1,4,5,8-naphthalenediimide, phosphomolybdic acid and europium salt in a solvent, and then heat and react to obtain the coordination polymer containing substituted polyacid and naphthalenediimide.
[0009] The coordination polymer containing substituted polyacid and naphthalenediimide prepared by the present invention is a two-dimensional metal-organic framework material formed by the coordination of the nitrogen oxide on N,N'-bis((4-N"-oxypyridinyl)methyl)-1,4,5,8-naphthalenediimide, phosphomolybdate ions and europium ions.
[0010] The structural formula of N,N'-bis((4-N"-oxypyridinyl)methyl)-1,4,5,8-naphthalenediimide used in the present invention is as follows:
[0011]
[0012] Preferably, the molar ratio of N,N'-bis((4-N"-oxypyridinyl)methyl)-1,4,5,8-naphthalenediimide, the phosphomolybdic acid to the europium ions in the europium salt is 1:2:5-10.
[0013] Optionally, the europium salt is europium trichloride.
[0014] Preferably, the solvent is a mixed solution of water and N,N-dimethylacetamide.
[0015] More preferably, the volume ratio of the water to the N,N-dimethylacetamide is 3:1.
[0016] Preferably, the temperature of the heating reaction is 100-110 °C, and the time is 48-72 h.
[0017] The third technical solution of the present invention: Provide an application of the above-mentioned coordination polymer containing substituted polyacid and naphthalenediimide in the preparation of a photocatalyst.
[0018] The fourth technical solution of the present invention: Provide an application of the above-mentioned coordination polymer containing substituted polyacid and naphthalenediimide in the photocatalytic degradation of basic red 9 or methylene blue.
[0019] The beneficial technical effects of the present invention are as follows:
[0020] The synthesis method provided by the present invention has low requirements for synthesis equipment, is simple and convenient to operate, has low cost, short preparation time, can be mass-produced, and the prepared coordination polymer containing substituted polyacid and naphthalenediimide has high crystallinity and good quality.
[0021] The coordination polymer containing substituted polyacid and naphthalenediimide provided by the present invention has good photothermal stability of the main structure, and the highest heat-resistant temperature can reach 380 °C.
[0022] The coordination polymer containing substituted polyacid and naphthalenediimide provided by the present invention has the characteristics of high quantum efficiency, high conversion rate and high chemical stability as a photocatalyst, has extremely high degradation efficiency for environmental pollutants basic red 9 and methylene blue, and has good practical value and application prospects. Description of the Drawings
[0023] Figure 1 It is an X-ray single crystal structure diagram of the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1.
[0024] Figure 2 It is a two-dimensional structure diagram of the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1.
[0025] Figure 3 It is a three-dimensional structure diagram of the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1.
[0026] Figure 4 It is a thermogravimetric curve of the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1.
[0027] Figure 5XRD pattern of the coordination polymer containing substituted polyoxoacid and naphthalenediimide prepared in Example 1.
[0028] Figure 6 UV-Vis spectrum of the coordination polymer containing substituted polyoxoacid and naphthalenediimide prepared in Example 1 for photocatalytic degradation of Basic Red 9.
[0029] Figure 7 UV-Vis spectrum of the coordination polymer containing substituted polyoxoacid and naphthalenediimide prepared in Example 1 for photocatalytic degradation of Methylene Blue.
[0030] Figure 8 XRD pattern of the coordination polymer containing substituted polyoxoacid and naphthalenediimide prepared in Example 2.
[0031] Figure 9 UV-Vis spectrum of the coordination polymer containing substituted polyoxoacid and naphthalenediimide prepared in Example 2 for photocatalytic degradation of Basic Red 9.
[0032] Figure 10 UV-Vis spectrum of the coordination polymer containing substituted polyoxoacid and naphthalenediimide prepared in Example 2 for photocatalytic degradation of Methylene Blue.
[0033] Figure 11 Degradation rate of photocatalytic degradation of Basic Red 9 by the coordination polymer containing substituted polyoxoacid and naphthalenediimide prepared in Example 1 during recycling.
[0034] Figure 12 Degradation rate of photocatalytic degradation of Methylene Blue by the coordination polymer containing substituted polyoxoacid and naphthalenediimide prepared in Example 1 during recycling.
[0035] Figure 13 XRD patterns of the coordination polymer containing substituted polyoxoacid and naphthalenediimide prepared in Example 1 before and after cyclic photocatalytic degradation of Basic Red 9.
[0036] Figure 14 UV-Vis spectrum of the raw material N,N'-bis((4-N''-oxypyridinyl)methyl)-1,4,5,8-naphthalenediimide for photocatalytic degradation of Basic Red 9.
[0037] Figure 15 UV-Vis spectrum of the raw material phosphomolybdic acid for photocatalytic degradation of Basic Red 9. Detailed Description of the Invention
[0038] Now, various exemplary embodiments of the present invention will 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, characteristics, and embodiments of the present invention. It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention.
[0039] It should be noted that the parts not described in detail in the present invention are all conventional operation means in the art and are not the focus of the present invention.
[0040] In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0041] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.
[0042] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.
[0043] The N,N'-bis((4-N''-oxypyridinyl)methyl)-1,4,5,8-naphthalenedicarboximide, phosphomolybdic acid, europium(III) chloride hexahydrate, and N,N-dimethylacetamide used in the examples of the present invention are all commercially available analytical pure reagents.
[0044] The temperature range of "room temperature" described in the examples of the present invention is 20 ± 10 °C.
[0045] Example 1
[0046] Preparation method of a coordination polymer containing a substituted polyacid and naphthalenedicarboximide:
[0047] 0.10 mmol of N,N'-bis((4-N''-oxypyridinyl)methyl)-1,4,5,8-naphthalenedicarboximide, 0.20 mmol of phosphomolybdic acid, and 0.50 mmol of europium(III) chloride hexahydrate were added to a mixed solution containing 2 mL of N,N-dimethylacetamide and 6 mL of water, and stirred at room temperature in an air atmosphere for 5 min to disperse evenly. Then it was transferred to a 25 mL Teflon autoclave, heated to 100 °C and kept at a constant temperature for 48 h. After the reaction, it was cooled to room temperature at a cooling rate of 10 °C / h. The obtained precipitate was washed with water to obtain yellow needle-like crystals, which were the coordination polymer containing a substituted polyacid and naphthalenedicarboximide, and the yield was about 73% (the yield was calculated based on N,N'-bis((4-N''-oxypyridinyl)methyl)-1,4,5,8-naphthalenedicarboximide). The synthesized coordination polymer was ground through a 300-mesh sieve and then reserved.
[0048] The X-ray single crystal structure diagram of the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1 is shown in Figure 1 ; The two-dimensional structure diagram is shown in Figure 2 ; The three-dimensional structure diagram is shown in Figure 3 .
[0049] It can be seen from Figure 1 that the europium atom adopts an eight-coordinate configuration and coordinates with three different N,N'-bis((4-N''-oxidopyridinyl)methyl)-1,4,5,8-naphthalenediimide ligands, one water molecule and a monoanionic Keggin-type phosphomolybdic acid anion. It can be seen from Figure 2 that the anionic phosphomolybdic acid anion and europium ions are connected to each other through three N,N'-bis((4-N''-oxidopyridinyl)methyl)-1,4,5,8-naphthalenediimide ligands to form a two-dimensional network structure. Figure 3 shows that the two-dimensional network structures are further connected into a three-dimensional structure by the weak interaction forces (anion-π and lone pair-π interactions) between the anionic phosphomolybdic acid anions and naphthalenediimide ligands.
[0050] Thermogravimetric analysis experiment was used to characterize the thermal stability of the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1. Specifically, under the purge of nitrogen, the temperature was raised at a heating rate of 10 °C / min, and the thermogravimetric curve of the coordination polymer containing substituted polyacid and naphthalenediimide was plotted. The results are shown in Figure 4 .
[0051] It can be seen from Figure 4 that there is a weight loss of about 13.8% in the temperature range from room temperature to 130 °C, indicating that the coordination polymer product containing substituted polyacid and naphthalenediimide contains more solvent molecules. After the solvent molecules volatilize, the product has basically no weight loss at 150-380 °C, indicating that the product can exist stably in this temperature range and has good thermal stability. In the range of 380-800 °C, the product has a sharp weight loss, indicating that the product begins to decompose.
[0052] The coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1 was analyzed by XRD. The XRD pattern is shown in Figure 5 .
[0053] It can be seen from Figure 5 that the characteristic peaks of the XRD pattern of the coordination polymer are consistent with the positions of the characteristic peaks of the theoretical simulation, indicating that the structure of the synthesized coordination polymer containing substituted polyacid and naphthalenediimide is consistent with the simulated structure, with high crystallinity and no obvious impurity phase.
[0054] Table 1 shows the X-ray single crystal diffraction data of the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1.
[0055] Table 1
[0056]
[0057] Application Example 1
[0058] Photocatalytic degradation of Basic Red 9 using the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1:
[0059] Weigh 40 mg of the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1, add it to a 100 mL quartz reaction vessel, and then add 10 -5 mol / L Basic Red 9 solution (50 mL). After continuously stirring for 2 hours in a dark environment, the catalyst (coordination polymer containing substituted polyacid and naphthalenediimide) and Basic Red 9 molecules reach an adsorption-desorption equilibrium. Place the quartz reaction vessel under the irradiation of a 300 W xenon lamp equipped with a filter and continuously stir. The wavelength range is 400 - 750 nm. The degradation process of Basic Red 9 is realized by online monitoring the change of its concentration through ultraviolet-visible spectroscopy. In the experiment, 5 mL of the solution is taken out from the reaction vessel every 5 minutes. After centrifuging to separate the photocatalyst, it is put into an ultraviolet-visible spectrometer for testing. The change of its ultraviolet-visible spectrum with illumination time is as Figure 6 shown.
[0060] It can be seen from Figure 6 that the absorbance of Basic Red 9 decreases rapidly with the increase of illumination time, indicating that Basic Red 9 is rapidly decomposed under the action of the catalyst. Within 20 minutes, its degradation rate can reach 89.3%. Within 30 minutes, Basic Red 9 can be basically completely degraded, and the degradation rate is 97.8%. The Basic Red 9 solution showing red turns into a colorless solution.
[0061] Application Example 2
[0062] Photocatalytic degradation of methylene blue using the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1:
[0063] Weigh 40 mg of the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 1, add it to a 100 mL quartz reaction vessel, and then add 10 -550 mL of methylene blue solution with a concentration of Figure 7 mol / L was continuously stirred for 2 hours in the dark environment to reach the adsorption-desorption equilibrium between the catalyst (coordination polymer containing substituted polyacid and naphthalenediimide) and methylene blue molecules. The quartz reaction vessel was placed under the irradiation of a 300 W xenon lamp equipped with a filter and continuously stirred, and the wavelength range was 400 - 750 nm. The degradation process of methylene blue was achieved by on-line monitoring the change of its concentration through ultraviolet-visible spectroscopy. In the experiment, 5 mL of the solution was taken out from the reaction vessel every 3 minutes. After the photocatalyst was separated by centrifugation, it was put into an ultraviolet-visible spectrometer for testing. The change of its ultraviolet-visible spectrum with the irradiation time is as
[0064] shown in Figure 7 . It can be seen from
[0065] Example 2
[0066] Preparation method of coordination polymer containing substituted polyacid and naphthalenediimide:
[0067] 0.20 mmol of N,N'-bis((4-N"-oxypyridyl)methyl)-1,4,5,8-naphthalenediimide, 0.4 mmol of phosphomolybdic acid and 2.00 mmol of europium(III) chloride hexahydrate were added to a mixed solution containing 12 mL of water and 4 mL of N,N-dimethylacetamide. It was stirred for 5 min at room temperature in the air atmosphere to disperse it evenly, and then transferred to a 25 mL Teflon autoclave, heated to 110 °C and kept at a constant temperature for 72 h. After the reaction was completed, it was cooled to room temperature at a cooling rate of 10 °C / h. The obtained precipitate was washed with water to obtain yellow needle-like crystals, which is the coordination polymer containing substituted polyacid and naphthalenediimide, and the yield was about 63% (calculated based on N,N'-bis((4-N"-oxypyridyl)methyl)-1,4,5,8-naphthalenediimide). The synthesized novel coordination polymer was ground through a 300-mesh sieve and then reserved.
[0068] XRD analysis was carried out on the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 2, and the results are shown in Figure 8 . It can be seen from Figure 8 that the characteristic peaks of the XRD pattern of this coordination polymer are consistent with the positions of the theoretically simulated characteristic peaks, indicating that the structure of the synthesized coordination polymer containing substituted polyacid and naphthalenediimide is consistent with the simulated structure, with high crystallinity and no obvious impurity phase.
[0069] Application Example 3
[0070] Photocatalytic degradation of Basic Red 9 using the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 2:
[0071] Weigh 80 mg of the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 2, add it to a 250 mL quartz reaction vessel, and then add 10 -5 mol / L Basic Red 9 solution of 100 mL. After continuously stirring for 2 hours in the dark environment, the catalyst (coordination polymer containing substituted polyacid and naphthalenediimide) and Basic Red 9 molecules reach adsorption-desorption equilibrium. Place the quartz reaction vessel under the irradiation of a 300 W xenon lamp equipped with a filter and continuously stir, with the wavelength range of 400 - 750 nm. The degradation process of Basic Red 9 is realized by on-line monitoring the change of its concentration through ultraviolet-visible spectroscopy. In the experiment, every 5 min, 5 mL of the solution is taken out from the reaction vessel. After centrifuging to separate the photocatalyst, it is put into an ultraviolet-visible spectrometer for testing. The change of its ultraviolet-visible spectrum with the irradiation time is as Figure 9 shown.
[0072] It can be seen from Figure 9 that the absorbance of Basic Red 9 decreases rapidly with the increase of the irradiation time, indicating that under the action of the catalyst, Basic Red 9 is rapidly decomposed. Within 20 minutes, its degradation rate reaches 86.3%. Within 30 minutes, Basic Red 9 can be basically completely degraded, and the degradation rate is 97.9%. The Basic Red 9 solution showing red turns into a colorless solution.
[0073] Application Example 4
[0074] Photocatalytic degradation of methylene blue using the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 2:
[0075] Weigh 80 mg of the coordination polymer containing substituted polyacid and naphthalenediimide prepared in Example 2, add it to a 250 mL quartz reaction vessel, and then add 10 -5 mol / L methylene blue solution of 100 mL. After continuously stirring for 2 hours in the dark environment, the catalyst (coordination polymer containing substituted polyacid and naphthalenediimide) and methylene blue molecules reach adsorption-desorption equilibrium. Place the quartz reaction vessel under the irradiation of a 300 W xenon lamp equipped with a filter and continuously stir, with the wavelength range of 400 - 750 nm. The degradation process of methylene blue is realized by on-line monitoring the change of its concentration through ultraviolet-visible spectroscopy. In the experiment, every 3 min, 5 mL of the solution is taken out from the reaction vessel. After centrifuging to separate the photocatalyst, it is put into an ultraviolet-visible spectrometer for testing. The change of its ultraviolet-visible spectrum with the irradiation time is as Figure 10 shown.
[0076] It can be seen from Figure 10 that the absorbance of methylene blue decreases rapidly with the increase of illumination time, indicating that methylene blue is rapidly decomposed under the action of the catalyst. Within 12 minutes, its degradation rate can reach 92.1%, and within 18 minutes, methylene blue can be completely degraded, with a degradation of 97.5%, and the methylene blue solution showing blue turns into a colorless solution.
[0077] To further prove the chemical stability and photocatalytic stability of the coordination polymer, the product after the photocatalytic experiment in Application Example 1 was centrifuged, and the recovered photocatalyst was washed with water and dried at room temperature. Then, a second photocatalytic experiment was carried out under the same experimental conditions as in Application Example 1. In order to collect sufficient samples, multiple experiments were carried out in parallel. The products after the second photocatalytic experiment were collected by the same method, and a third experiment was carried out. The degradation rates of basic red 9 and methylene blue after each cycle were calculated, and the results are as Figure 11 and 12 shown.
[0078] It can be seen from Figure 11 and 12 that the photocatalytic performance of the coordination polymer containing substituted polyoxoacid and naphthalenediimide prepared in Example 1 did not decrease significantly after three cycles of use, indicating that the coordination polymer has good photocatalytic stability.
[0079] At the same time, the coordination polymer containing substituted polyoxoacid and naphthalenediimide after three cycles of photocatalytic degradation of basic red 9 was characterized by XRD, and the results are as Figure 13 .
[0080] It can be seen from Figure 13 that the XRD pattern after three cycles of photocatalysis is consistent with the simulated pattern of the sample without photocatalytic experiment, indicating that the structure of the coordination polymer has not changed and it has good photocatalytic stability. Figure 1
[0081] Application Example 5
[0082] Using the raw material N,N'-bis((4-N''-oxypyridyl)methyl)-1,4,5,8-naphthalenediimide for photocatalytic degradation of basic red 9:
[0083] Weigh 80 mg of N,N'-bis((4-N''-oxypyridyl)methyl)-1,4,5,8-naphthalenediimide, add it to a 100 mL quartz reaction vessel, and then add 10 -5100 mL of a basic red 9 solution at Figure 14 mol / L was continuously stirred for 2 hours in the dark to achieve an adsorption - desorption equilibrium between the catalyst N,N'-bis((4-N''-oxypyridinyl)methyl)-1,4,5,8-naphthalenediimide and basic red 9 molecules. The quartz reaction vessel was placed under irradiation of a 300 W xenon lamp equipped with a filter and continuously stirred, with a wavelength range of 400 - 750 nm. The degradation process of basic red 9 was achieved by on-line monitoring of the change in its concentration through ultraviolet - visible spectroscopy. In the experiment, 5 mL of the solution was taken out from the reaction vessel every 5 minutes. After centrifuging to separate the photocatalyst, it was put into an ultraviolet - visible spectrometer for testing. The change in its ultraviolet - visible spectrum with the irradiation time is as
[0084] shown in Figure 14 . It can be seen from
[0085] that the absorbance of basic red 9 changes insignificantly with the increase in irradiation time, indicating that the photocatalytic degradation efficiency of N,N'-bis((4-N''-oxypyridinyl)methyl)-1,4,5,8-naphthalenediimide for basic red 9 is significantly lower than that of the coordination polymers containing substituted polyoxoacids and naphthalenediimides prepared in Examples 1 - 2. The coordination of N,N'-bis((4-N''-oxypyridinyl)methyl)-1,4,5,8-naphthalenediimide with europium ions and phosphomolybdic acid can significantly improve its catalytic activity.
[0086] Application Example 6
[0087] Weigh 80 mg of phosphomolybdic acid and add it to a 250 mL quartz reaction vessel. Then add 10 -5 mol / L of 100 mL basic red 9 solution. Continuously stir for 2 hours in the dark to achieve an adsorption - desorption equilibrium between the catalyst phosphomolybdic acid and basic red 9 molecules. Place the quartz reaction vessel under irradiation of a 300 W xenon lamp equipped with a filter and continuously stir, with a wavelength range of 400 - 750 nm. The degradation process of basic red 9 was achieved by on-line monitoring of the change in its concentration through ultraviolet - visible spectroscopy. In the experiment, 5 mL of the solution was taken out from the reaction vessel every 5 min. After centrifuging to separate the photocatalyst, it was put into an ultraviolet - visible spectrometer for testing. The change in its ultraviolet - visible spectrum with the irradiation time is as Figure 15 shown in
[0088] It can be seen from Figure 15 that after 30 minutes of irradiation, the absorbance of basic red 9 changes insignificantly, indicating that the photocatalytic degradation efficiency of phosphomolybdic acid for basic red 9 is significantly lower than that of the coordination polymers containing substituted polyoxoacids and naphthalenediimides prepared in Examples 1 - 2.
[0089] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the spirit of the design of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.
Claims
1. A coordination polymer containing a substituted polyacid and naphthalenediimide, characterized in that, The coordination polymer containing a substituted polyoxoacid and naphthalenediimide is a two-dimensional metal-organic framework material formed by the coordination of the nitrogen oxide on N,N'-bis((4-N"-oxypyridinyl)methyl)-1,4,5,8-naphthalenediimide, phosphomolybdate ions, and europium ions; the coordination polymer containing a substituted polyoxoacid and naphthalenediimide belongs to the triclinic system, space group P-1, and the unit cell parameters α = 83.489(5)°, β = 84.170(4)°, γ = 87.570(4)°.
2. A method for preparing the coordination polymer containing substituted polyacid and naphthalenediimide according to claim 1, characterized in that, It includes the following steps: Dissolve N,N'-bis((4-N''-oxypyridinyl)methyl)-1,4,5,8-naphthalenedicarboximide, phosphomolybdic acid and europium salt in a solvent, and then heat and react to obtain the coordination polymer containing substituted polyacid and naphthalenedicarboximide.
3. The preparation method of the coordination polymer containing substituted polyacid and naphthalenediimide according to claim 2, characterized in that, The molar ratio of N,N'-bis((4-N''-oxypyridinyl)methyl)-1,4,5,8-naphthalenedicarboximide, the phosphomolybdic acid to europium ions in the europium salt is 1:2:5 to 10.
4. The preparation method of the coordination polymer containing substituted polyacid and naphthalenediimide according to claim 2, characterized in that, The solvent is a mixed solution of water and N,N-dimethylacetamide.
5. The preparation method of the coordination polymer containing a substituted polyacid and naphthalenediimide according to claim 4, characterized in that, The volume ratio of the water to the N,N-dimethylacetamide is 3:
1.
6. The preparation method of the coordination polymer containing a substituted polyacid and naphthalenediimide according to claim 21, characterized in that, The temperature of the heating reaction is 100 to 110 °C, and the time is 48 to 72 h.
7. Application of the coordination polymer containing substituted polyacid and naphthalenedicarboximide according to claim 1 in the preparation of a photocatalyst.
8. Application of the coordination polymer containing substituted polyacid and naphthalenedicarboximide according to claim 1 in the photocatalytic degradation of basic red 9 or methylene blue.