Flexible perylene bisimide covalent organic framework material as well as preparation method and application thereof
By combining FAL-COF with the flexible peryleneimide-based covalent organic frame material with the interfinger electrode, a gas-sensitive sensor is constructed, which solves the problems of large, high cost and limited real-time monitoring of ammonia detection equipment in the prior art, and realizes room temperature Fast, stable and low-cost high-sensitivity detection effect.
Patent Information
- Application Number
- CN202411377525.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2024-12-27
AI Technical Summary
The prior art has limitations in detecting ammonia, high cost and real-time monitoring, and it is particularly difficult to achieve portable and low-cost high-sensitivity detection.
FAL-COF, a flexible peryleneimide-based covalent organic frame material, was synthesized by solvent-thermal method and combined with an interfinger electrode to construct a gas-sensitive sensor to achieve high sensitivity detection of ammonia.
Fast, stable and low-cost ammonia detection at room temperature, with a response concentration as low as 1 ppm, fast response and recovery time, good selectivity and anti-interference, suitable for industrial applications.
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Figure CN119192511A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of preparation and application of covalent organic framework materials, and in particular to a preparation method of a flexible perylene imide-based covalent organic framework material FAL-COF and its application in detecting ammonia. Background Art
[0002] Ammonia (NH3) is one of the air pollutants, mainly from industrial / automobile exhaust emissions and the combustion of biomass / fossil fuels. The Occupational Safety and Health Administration (OSHA) states that long-term exposure to NH3 concentrations of 25 ppm or above can cause respiratory diseases and even death. In addition, ammonia levels can also be used as a tracer to detect food spoilage and as a biomarker for kidney disease and liver dysfunction. Chronic kidney disease patients lose kidney function and are unable to filter metabolic waste, which leads to waste accumulation in the circulatory system and elevated ammonia levels in the blood, breath, and body fluids. Therefore, designing NH3 sensors with good sensing performance is of great significance for environmental protection and exhaled breath monitoring.
[0003] Currently, effective detection of ammonia can be achieved through the following methods: optical method, gas chromatography, acoustic method, etc. However, optical gas sensors are large in size, which is not conducive to portable detection, and their high cost limits their application. Therefore, these methods have great limitations in detecting ammonia, especially in real-time monitoring of ammonia. Summary of the invention
[0004] The object of the present invention is to provide a method for preparing a flexible perylene imide-based covalent organic framework material for detecting ammonia, characterized in that the method comprises the following steps: (1) Add 2,4,6-tris(4-formylphenoxy)-1,3,5-triazine and 3,4,9,10-perylenetetracarboxylic acid dihydrazide into a heat-resistant glass tube, add trimethylbenzene / dioxane, and ultrasonically disperse for 2-10 min. After mixing the two dispersions together, add 0.2-0.6 mL of formic acid, and then perform three cycles of degassing. Seal the tube and react at 70-90 °C for 70-76 h. The mass ratio of 2,4,6-tris(4-formylphenoxy)-1,3,5-triazine and 3,4,9,10-perylenetetracarboxylic acid dihydrazide is 1.3:1, and the total mass is 150-200 mg. The volume ratio of trimethylbenzene, dioxane and formic acid is 1:1:0.2, and the total volume is 1.5-9.0 mL. (2) After the reaction is completed, the product is filtered and then washed with N,N-dimethylformamide, acetone and tetrahydrofuran in sequence until it is colorless. It is then vacuum dried at 40-60 °C for 10-16 h to obtain a purple-black powder, which is FAL-COF.
[0005] The flexible perylene imide-based covalent organic framework material is referred to as FAL-COF, and its structural formula is shown in Formula 1; Formula 1 The application of the flexible perylene imide-based covalent organic framework material in the preparation of an ammonia gas sensor.
[0006] A gas sensor for detecting ammonia gas is prepared by synthesizing a FAL-COF covalent organic framework material by a solvothermal method, and combining an ethanol solution containing the material with an interdigital electrode to achieve highly sensitive detection of ammonia gas.
[0007] The preparation method for constructing a gas-sensitive sensor for detecting ammonia is as follows: (1) A 6B pencil was used to directly draw a flexible interdigital electrode on a commonly used A4 office paper. The interdigital electrode consisted of 10 pairs of graphite electrodes with the following dimensions: 6000 μm coverage length, 20 nm electrode thickness, 200 μm electrode width, and 100 μm electrode thickness. (2) A 0.8 mg mL -1 The ethanol solution of FAL-COF is combined with the interdigital electrodes, and after the solvent evaporates, it is tightly attached to the interdigital electrodes to obtain an ammonia gas sensitive sensor.
[0008] A gas sensor for detecting ammonia prepared by the present invention comprises a covalent organic framework material FAL-COF constructed by perylene imide compounds and triazine compounds, and the covalent organic framework material FAL-COF has the advantages of good responsiveness, high sensitivity, fast response and recovery time, good reproducibility and strong selectivity to ammonia in the range of 3-100 ppm at room temperature, and such a covalent organic framework material exhibits excellent gas-sensing performance.
[0009] Advantages of the present invention: (1) The preparation method of the covalent organic framework material for detecting ammonia used in the present invention is simple and has relatively low energy consumption; (2) The gas sensor for detecting ammonia of the present invention has the advantages of being able to effectively and quickly measure ammonia at room temperature without any safety hazards; the response concentration to harmful gas ammonia is as low as 1 ppm, the response and recovery time are fast, the stability is good, the anti-interference ability is strong, and the selectivity is good; the structure and preparation process are simple, the cost is low, and it is easy to realize industrialization. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 is a scanning electron micrograph of FAL-COF; Figure 2 is the Fourier transform infrared spectrum of FAL-COF; Figure 3 is the X-ray photoelectron spectrum of FAL-COF; Figure 4 is the X-ray diffraction pattern of FAL-COF; Figure 5 This is the response and recovery curve of the ammonia gas sensor to 10 ppm ammonia (room temperature); Figure 6 This is the dynamic response curve of the ammonia gas sensor to 3-100 ppm ammonia (room temperature); Figure 7 This is the long-term stability curve of the ammonia gas sensor for 10 ppm ammonia within 30 days (room temperature condition); Figure 8 This is a schematic diagram of the selectivity of an ammonia gas sensor to different types of gases at various concentrations. DETAILED DESCRIPTION
[0011] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. However, the content of the present invention is not limited to the following embodiments. The details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.
[0012] It should be understood that the terms used in the examples of the present invention are intended to describe specific embodiments rather than to limit the scope of protection of the present invention. The methods in the following examples where specific conditions are not specified are generally carried out under conventional conditions or under conditions recommended by various manufacturers.
[0013] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in the present invention, the two endpoints of each numerical range and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention. Any methods, equipment and materials of the prior art similar or equivalent to the methods, equipment and materials described in the embodiments of the present invention can also be used to implement the present invention.
[0014] Example 1 Preparation method of flexible perylene imide-based covalent organic framework material FAL-COF 1.1 (1) 88.4 mg of 2,4,6-tris(4-formylphenoxy)-1,3,5-triazine and 66.7 mg of 3,4,9,10-perylenetetracarboxylic acid dihydrazide were placed in a heat-resistant glass tube, and then trimethylbenzene / dioxane (1:1, 2 mL) was added. The two mixtures were sonicated for 5 min to obtain a uniform dispersion; then, the two dispersions were mixed together and the mixture was briefly sonicated for about 15 s; subsequently, 0.2 mL of formic acid was slowly added, and the heat-resistant glass tube was sealed, and then the reaction system was degassed through 3 "vacuum-freeze-thaw" cycles, sonicated for 30 min, and allowed to stand at 80 °C for 72 h; the formed solid was collected after filtration and washed with N,N-dimethylformamide, acetone and tetrahydrofuran respectively until the filtrate was colorless. The obtained powder was dried overnight under vacuum at 50 °C to obtain black FAL-COF powder; (2) Comprehensive characterization of the obtained products, Figure 1 is a scanning electron microscope cross-sectional image of a flexible perylene imide-based covalent organic material, showing the surface morphology of the material; Figure 2 As shown, the Fourier transform infrared spectrum shows that at 1705cm -1 and 1783 cm -1 The peak position at 1369 cm -1 The characteristic stretching vibration peak of C−N bond appears at the peak position of 840 cm -1 The aldehyde peak at 1470 nm disappeared, and Fourier transform infrared spectroscopy analysis confirmed the formation of the imide bond, thereby proving the completion of the reaction and the integrity of the framework structure. Figure 3 As shown, the X-ray photoelectron spectroscopy shows that FAL-COF has binding energies corresponding to C 1s, N 1s, and O 1s at 283.6, 400.3, and 531.3 eV; Figure 4 This is the X-ray diffraction pattern of FAL-COF; the diffraction peaks at 9.78°, 14.77°, and 19.16° correspond to the high-order diffraction of the (200), (300), and (400) crystal planes, respectively, revealing that the material has a high molecular order; 1.2 (1) 105.9 mg of 2,4,6-tris(4-formylphenoxy)-1,3,5-triazine and 75.7 mg of 3,4,9,10-perylenetetracarboxylic acid dihydrazide were placed in a heat-resistant glass tube, and then trimethylbenzene / dioxane (1:1, 4 mL) was added. The two mixtures were sonicated for 5 min to obtain a uniform dispersion; then, the two dispersions were mixed together and the mixture was briefly sonicated for about 18 s; subsequently, 0.4 mL of formic acid was slowly added, and the heat-resistant glass tube was sealed, and then the reaction system was degassed through 3 "vacuum-freeze-thaw" cycles, sonicated for 35 min, and allowed to stand at 90 °C for 76 h; the formed solid was collected after filtration and washed with N,N-dimethylformamide, acetone and tetrahydrofuran respectively until the filtrate was colorless. The obtained powder was dried overnight under vacuum at 55 °C to obtain black FAL-COF powder; (2) Comprehensive characterization of the obtained product: the results are consistent with 1.1.
[0015] Example 2 Preparation of ammonia gas sensor (1) A 6B pencil was used to directly draw a flexible interdigital electrode on a commonly used A4 office paper. The interdigital electrode consisted of 10 pairs of graphite electrodes with the following dimensions: 6000 μm coverage length, 20 nm electrode thickness, 200 μm electrode width, and 100 μm electrode thickness. (2) A 0.8 mg mL -1 The ethanol solution of FAL-COF is combined with the interdigital electrodes, and after the solvent evaporates, it is tightly attached to the interdigital electrodes to obtain an ammonia gas sensitive sensor.
[0016] Example 3 Performance test of ammonia gas sensor The covalent organic framework material FAL-COF obtained in Example 2 was selected to construct a gas-sensitive testing device, and a gas-sensitive testing experiment was carried out. The gas-sensitive testing process is carried out in a relatively mild environment (room temperature, external atmospheric pressure and dry air) and a current-voltage curve range of -10-10 V, starting from a bias voltage of 0.0 V to test the gas-sensitive performance. The testing instrument used: Agilent B2902A precision source / measurement unit. Among them, the gas sensors prepared using the covalent organic framework material FAL-COF prepared in Example 1 were tested separately, and the test results were consistent; all Figure 5-8 As shown. Figure 5 As shown in Figure 2, the response / recovery times are 53 s and 85 s, respectively; Figure 6 As shown in Figure 2, the covalent organic framework material FAL-COF gas sensor has a good response to 3-100 ppm ammonia, and the detection limit can reach 1 ppm; Figure 7As shown in the figure, the long-term stability curve of the covalent organic framework material FAL-COF gas sensor within 50 days shows that the gas sensor has good stability; Figure 8 As shown, the covalent organic framework material FAL-COF gas sensor was tested for gas sensitivity to different gases including ammonia, tetrahydrofuran, nitrogen dioxide, ethanol, carbon monoxide, methanol hexane, benzene and acetone. It can be seen that among various test gases, the covalent organic framework material FAL-COF showed the greatest response to ammonia and had good selectivity for ammonia.
[0017] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.
Claims
1. A method for preparing a flexible perylene imide-based covalent organic framework material FAL-COF, characterized in that: The following steps are involved: (1) Add 2,4,6-tris(4-formylphenoxy)-1,3,5-triazine and 3,4,9,10-perylenetetracarboxylic acid dihydrazide into a heat-resistant glass tube, add trimethylbenzene / dioxane, and perform ultrasonic dispersion for 2-10 min. After the two dispersions are mixed together, 0.2-0.6 mL of formic acid is added, and then three cycles of degassing are performed. The tube is sealed and reacted at 70-90 °C for 70-76 h. The mass ratio of 2,4,6-tris(4-formylphenoxy)-1,3,5-triazine and 3,4,9,10-perylenetetracarboxylic acid dihydrazide is 1.3:1, and the total mass is 150-200 mg. The volume ratio of trimethylbenzene, dioxane and formic acid is 1:1:0.2, and the total volume is 1.5-9.0 mL. (2) After the reaction is completed, the product is filtered and then washed with N,N-dimethylformamide, acetone and tetrahydrofuran in sequence until it is colorless. It is then vacuum dried at 40-60 °C for 10-16 h to obtain a purple-black powder, which is FAL-COF.
2. A flexible perylene imide-based covalent organic framework material FAL-COF, which has the structural characteristic of being a flexible covalent organic framework material connected by secondary amine bonds and having rotational freedom.
3. The flexible perylene imide-based covalent organic framework material FAL-COF according to claim 2, wherein the flexible perylene imide-based covalent organic framework material FAL-COF is used for detecting ammonia gas at room temperature.
4. The use of a flexible perylene imide-based covalent organic framework material FAL-COF according to claim 3, characterized in that: In the concentration range of 3-100 ppm, as the ammonia concentration increases, the response current gradually increases, and there is a linear relationship between the ammonia concentration and the current response.
5. The use of a flexible perylene imide-based covalent organic framework material FAL-COF according to claim 3, characterized in that: The detection limit for ammonia is 1 ppm.
6. The use of a flexible perylene imide-based covalent organic framework material FAL-COF according to claim 3, characterized in that: The response and recovery times to ammonia were 53 s and 85 s, respectively.