Linear polyimide bifunctional photo / piezoelectric catalytic material and application thereof
The linear polyimide catalytic material synthesized by the solvothermal method solves the problem of insufficient application of polymer semiconductor materials in the field of piezoelectric catalysis in the existing technology, and realizes the improvement of photo-piezoelectric synergistic catalytic performance, which is suitable for both photocatalysis and piezoelectric catalysis.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA UNIV OF GEOSCIENCES (BEIJING)
- Filing Date
- 2024-01-03
- Publication Date
- 2026-06-05
Smart Images
Figure CN117887069B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photo / piezoelectric catalytic materials technology, and more specifically, to a linear polyimide bifunctional photo / piezoelectric catalytic material and its applications. Background Technology
[0002] In clean energy technologies, photocatalysis and piezoelectric catalysis have attracted widespread attention for their ability to convert solar and mechanical energy into chemical energy, respectively. Among the semiconductor materials commonly used in photocatalysis, some are unique in that they are both photocatalysts and piezoelectric catalysts, such as BaTiO3, CdS, ZnO, BiWO3, and MoS2. In recent years, polymer semiconductor materials have emerged as a new class of catalysts due to their abundant Earthly sources, ease of synthesis and processability, tunable electronic and band structures at the molecular level, and high physicochemical stability, and are gradually gaining increasing attention. Current research progress focuses on applications in photocatalysis, primarily using conjugated linear polymers, conjugated microporous polymers, and conjugated organic framework polymers for photocatalytic water splitting to produce hydrogen, photocatalytic hydrogen peroxide production, and photocatalytic degradation of environmental pollutants. Reports in the field of piezoelectric catalysis are scarce, and those that exist mainly focus on polyvinylidene fluoride (PVDF).
[0003] Among polymer semiconductor materials, polyimide (PI) is a typical DA-type polymer. Its tunable band gap, ease of molecular design, simple synthesis methods, and non-toxicity have garnered widespread attention since its photocatalytic activity was reported in 2012. Crystalline polyimide materials, due to their non-centrosymmetric properties, possess potential applications in piezoelectric catalysis. Therefore, designing a polyimide catalytic material that can efficiently harvest solar energy as a photocatalyst and convert mechanical energy into chemical energy as a piezoelectric catalyst is an urgent problem to be solved. Summary of the Invention
[0004] This invention addresses the problems existing in the prior art by providing a linear polyimide bifunctional photo / piezoelectric catalytic material and its applications. The linear polyimide catalytic material prepared by this invention can function as both a photocatalyst and a piezoelectric catalyst, and its catalytic performance is significantly improved when photo-piezoelectric effects are used simultaneously.
[0005] The first aspect of the present invention is to provide a linear polyimide bifunctional photo / piezoelectric catalytic material, said linear polyimide being prepared from dianhydride and diamine, wherein the dianhydride is selected from at least one of pyromellitic dianhydride (PMDA) and biphenyl dianhydride (BPDA), and the diamine is selected from at least one of 4,4'-diaminobenzoyl aniline (DABA) and 3-hydroxy-4,4'-diaminobenzoyl aniline, wherein the molar ratio of the dianhydride to the diamine is 1:0.9-1.1.
[0006] Preferably, the linear polyimide is a compound as shown in general formula I:
[0007]
[0008] Ar is selected from R is selected from H or OH.
[0009] The second aspect of this invention is to provide a method for preparing a linear polyimide bifunctional photo / piezoelectric catalytic material, comprising the following steps:
[0010] 1) A non-protic strongly polar solvent and an alcohol solvent are mixed evenly to obtain a mixed solvent;
[0011] 2) Dissolve the dianhydride in the mixed solvent, then add the diamine and stir to obtain a mixed solution;
[0012] 3) The mixed solution is reacted at high temperature, cooled, washed, and dried to obtain the final product.
[0013] Preferably, the aprotic strongly polar solvent mentioned in step 1) is selected from at least one of N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), and N,N-dimethylacetamide (DMAc).
[0014] More preferably, the aprotic strongly polar solvent mentioned in step 1) is N,N-dimethylformamide.
[0015] Preferably, the alcohol solvent mentioned in step 1) is selected from at least one of diols and polyols.
[0016] More preferably, the alcohol solvent mentioned in step 1) is ethylene glycol.
[0017] Preferably, the volume ratio of the aprotic strongly polar solvent to the alcohol solvent in step 1) is 1:0.25-1.5.
[0018] More preferably, the volume ratio of the aprotic strongly polar solvent to the alcohol solvent in step 1) is 1:0.8.
[0019] Preferably, the raw materials (dianhydride and diamine) in step 2) account for 10-25 wt% of the total reaction system.
[0020] More preferably, the raw materials (dianhydride and diamine) in step 2) account for 18 wt% of the total reaction system.
[0021] Preferably, the reaction temperature in step 3) is 160-200℃.
[0022] More preferably, the reaction temperature in step 3) is 180°C.
[0023] Preferably, the reaction time in step 3) is 36-50 hours.
[0024] More preferably, the reaction time in step 3) is 40 hours.
[0025] The third aspect of the present invention relates to the application of the linear polyimide bifunctional photo / piezocatalytic material as described above in the fields of photocatalysis, piezocatalysis, and photo-piezo-co-catalytic synergistic catalysis, including at least one of degrading various pollutants in water, preparing hydrogen peroxide to decompose water to produce hydrogen, and reducing CO2 to carbon-containing fuels.
[0026] Compared with the prior art, the present invention has the following advantages: (1) The method is simple to operate and the reaction is controllable; (2) The linear polyimide bifunctional photo / piezoelectric catalytic material of the present invention has excellent photocatalytic response and piezoelectric response performance, and the catalytic performance is greatly improved when photo-piezoelectric is used simultaneously. Attached Figure Description
[0027] Figure 1 The image shows the FTIR spectrum of the prepared PI catalyst.
[0028] Figure 2 The image shows the XRD pattern of the prepared PI catalyst.
[0029] Figure 3 SEM image of the prepared PI catalyst material.
[0030] Figure 4 The bar chart shows the hydrogen peroxide production of the prepared PI catalyst under different conditions. Detailed Implementation
[0031] It is worth noting that the raw materials used in this invention are all commercially available products, and their sources are not specifically limited.
[0032] The performance evaluation method of the PI catalytic material obtained in the following examples is as follows:
[0033] Structural evaluation methods for PI catalytic materials:
[0034] Fourier transform infrared spectroscopy (FT-IR): Measured using a Thermo Scientific Nicolet iS20 Fourier transform infrared spectrometer.
[0035] X-ray diffraction (XRD): The structure of the prepared PI piezoelectric material was analyzed using a Bruker D8 Advance series wide-angle X-ray diffractometer in Germany. The scanning speed was 5° / min and the scanning range was 5°-50°.
[0036] Methods for evaluating the microstructure of PI catalytic materials:
[0037] Scanning electron microscopy (SEM): The prepared PI catalyst was tested on a Hitachi S-4800 series scanning electron microscope manufactured in Japan.
[0038] Performance evaluation methods for PI catalytic materials:
[0039] Photocatalytic performance: Under xenon lamp irradiation (light intensity 300mW / cm²) 2 The hydrogen peroxide production of the photocatalyst was characterized by adding 20 mg of the catalyst to a mixed solution of 45 mL water and 5 mL ethanol. The mixture was stirred in the dark for 1 h to reach adsorption-desorption equilibrium between the photocatalyst and the suspension. Irradiation was then initiated, and 3 mL of the supernatant was collected every 30 min and centrifuged to remove residual nanoparticles. The concentration of hydrogen peroxide was determined using a typical iodometric method, by mixing 2 mL of 0.1 M KI solution with 50 μL of H2O. 24 Mo7N6O 24 • 0.01 M 4H2O solution was dropped into 500 μL of supernatant and reacted for 20 min. Then the absorbance of the solution was measured at 352 nm using a MAPADA UV-6100 UV-Vis spectrophotometer.
[0040] Piezoelectric catalytic performance: Characterized by hydrogen peroxide production under ultrasonic vibration (40 kHz, 240 W). 20 mg of catalyst was added to a mixed solution of 45 mL water and 5 mL ethanol. The mixture was stirred in the dark for 1 h to reach adsorption-desorption equilibrium between the photocatalyst and the suspension. Then, the ultrasonic treatment was initiated, and 3 mL of supernatant was collected every 30 min and centrifuged to remove residual nanoparticles. The concentration of hydrogen peroxide was determined using a typical iodometric method, mixing 2 mL of 0.1 M KI solution with 50 μL of H2O. 24 Mo7N6O 24 • 0.01 M 4H2O solution was dropped into 500 μL of supernatant and reacted for 20 min. Then the absorbance of the solution was measured at 352 nm using a MAPADA UV-6100 UV-Vis spectrophotometer.
[0041] Photo-piezoelectric catalytic performance: Under xenon lamp irradiation (light intensity 300mW / cm²), 2 The hydrogen peroxide production was characterized by simultaneous ultrasonic vibration (40 kHz, 240 W). 20 mg of catalyst was added to a mixture of 45 mL water and 5 mL ethanol. The mixture was stirred in the dark for 1 h to reach adsorption-desorption equilibrium between the photocatalyst and the suspension. Then, xenon lamp illumination was initiated, and ultrasonication was performed simultaneously. 3 mL of the supernatant was collected every 30 min and centrifuged to remove residual nanoparticles. The concentration of hydrogen peroxide was determined using a typical iodometric method, mixing 2 mL of 0.1 M KI solution with 50 μL of H2O. 24 Mo7N6O 24 • 0.01 M 4H2O solution was dropped into 500 μL of supernatant and reacted for 20 min. Then the absorbance of the solution was measured at 352 nm using a MAPADA UV-6100 UV-Vis spectrophotometer.
[0042] Example 1
[0043] The PI catalyst was prepared using pyromellitic dianhydride (PMDA) and 4,4'-diaminobenzoyl aniline (DABA).
[0044] N,N-dimethylformamide (DMF) and ethylene glycol were uniformly mixed at a volume ratio of 1:0.8 to prepare a 9 mL mixed solvent. Then, 1.0906 g of PMDA was weighed and dissolved in the mixed solvent and stirred until dissolved. Subsequently, 1.1364 g of DABA was added and stirred for 1 h until completely dissolved. The dissolved solution was transferred to a Teflon autoclave and then to a high-temperature oven and reacted at 180 °C for 40 h. The reaction was allowed to cool naturally, and the resulting product was washed three times with DMF and water, respectively. After centrifugation, it was dried in a vacuum oven for 12 h to obtain the PI catalyst.
[0045] 20 mg of the prepared PI catalyst was used to conduct experiments on photocatalysis, piezoelectric catalysis, and photo-piezoelectric synergistic catalysis for hydrogen peroxide production. After 120 minutes, the hydrogen peroxide yields were 322.8 μmol / L, 110.8 μmol / L, and 484.5 μmol / L, respectively.
[0046] FTIR spectra are attached. Figure 1 As shown in Example 1, all characteristic peaks of imide were present;
[0047] XRD patterns are attached. Figure 2 As shown in Example 1, the sample is a highly ordered crystalline PI;
[0048] SEM images are attached. Figure 3 As shown in Example 1, the sample is in the form of nanosheets;
[0049] The hydrogen peroxide production chart is attached. Figure 4 As shown in Example 1;
[0050] Specific data are listed in Table 1, Example 1.
[0051] Example 2
[0052] The PI catalyst was prepared using biphenyl tetracarboxylic dianhydride (BPDA) and 4,4'-diaminobenzoyl aniline (DABA).
[0053] The preparation method is the same as in Example 1, except that 1.0906g PMDA is replaced with 1.4711g BPDA.
[0054] 20 mg of the prepared PI catalyst was used to conduct experiments on photocatalysis, piezoelectric catalysis, and photo-piezoelectric synergistic catalysis for hydrogen peroxide production. After 120 minutes, the hydrogen peroxide yields were 264.4 μmol / L, 83.6 μmol / L, and 391.3 μmol / L, respectively.
[0055] FTIR spectra are attached. Figure 1 As shown in Example 2, all characteristic peaks of the imide were present;
[0056] XRD patterns are attached. Figure 2 As shown in Example 2, the sample is a highly ordered crystalline PI;
[0057] SEM images are attached. Figure 3 As shown in Example 2, the sample is in sheet form;
[0058] The hydrogen peroxide production chart is attached. Figure 4 As shown in Example 2;
[0059] Specific data are listed in Table 1, Example 2.
[0060] Example 3
[0061] The PI catalyst was prepared using pyromellitic dianhydride (PMDA) and 3-hydroxy-4,4'-diaminobenzoyl aniline.
[0062] The preparation method is the same as in Example 1, except that 1.1364g of DABA is replaced with 1.2164g of 3-hydroxy-4,4'-diaminobenzoyl aniline.
[0063] 20 mg of the prepared PI catalyst was used to conduct experiments on photocatalysis, piezoelectric catalysis, and photo-piezoelectric synergistic catalysis for hydrogen peroxide production. After 120 minutes, the hydrogen peroxide yields were 468.8 μmol / L, 258.4 μmol / L, and 798.2 μmol / L, respectively.
[0064] FTIR spectra are attached. Figure 1As shown in Example 3, all characteristic peaks of the imide were present;
[0065] XRD patterns are attached. Figure 2 As shown in Example 3, the sample is a highly ordered crystalline PI;
[0066] SEM images are attached. Figure 3 As shown in Example 3, the sample is a nanoflower-like structure assembled from nanosheets;
[0067] The hydrogen peroxide production chart is attached. Figure 4 As shown in Example 3;
[0068] Specific data are listed in Table 1, Example 3.
[0069] Example 4
[0070] The PI catalyst was prepared using biphenyl tetracarboxylic dianhydride (BPDA) and 3-hydroxy-4,4'-diaminobenzoyl aniline.
[0071] The preparation method is the same as in Example 1, except that 1.0906g PMDA is replaced with 1.4711g BPDA and 1.1364g DABA is replaced with 1.2164g 3-hydroxy-4,4'-diaminobenzoyl aniline.
[0072] 20 mg of the prepared PI catalyst was used to conduct experiments on photocatalysis, piezoelectric catalysis, and photo-piezoelectric synergistic catalysis for hydrogen peroxide production. After 120 minutes, the hydrogen peroxide yields were 401.2 μmol / L, 240.4 μmol / L, and 717.8 μmol / L, respectively.
[0073] FTIR spectra are attached. Figure 1 As shown, all characteristic peaks of imide are present;
[0074] XRD patterns are attached. Figure 2 As shown, the sample is crystalline PI;
[0075] SEM images are attached. Figure 3 As shown, the sample is in sheet form;
[0076] The hydrogen peroxide production chart is attached. Figure 4 As shown;
[0077] The specific data is listed in Table 1.
[0078] Comparative Example 1: Kapton film
[0079] Cut a piece of the same weight (20mg) Polyimide film (Dopont, 25 μm thick, approximately 6 cm² in area) 2Experiments were conducted to produce hydrogen peroxide using photocatalysis, piezoelectric catalysis, and photo-piezoelectric synergistic catalysis. After 120 minutes, the yields of hydrogen peroxide were 20.7 μmol / L, 32.6 μmol / L, and 59.2 μmol / L, respectively.
[0080] The hydrogen peroxide production chart is attached. Figure 4 As shown in Comparative Example 1;
[0081] Specific data are listed in Table 1, Comparative Example 1.
[0082] Comparative Example 2: No catalyst added
[0083] The hydrogen peroxide production experiments were carried out directly in 50 mL of aqueous solution (10 vol% ethanol) using photocatalysis, piezoelectric catalysis, and photo-piezoelectric synergistic catalysis. After 120 minutes, the hydrogen peroxide yields were 17.7 μmol / L, 26.2 μmol / L, and 42.1 μmol / L, respectively.
[0084] The hydrogen peroxide production chart is attached. Figure 4 As shown in Comparative Example 2;
[0085] Specific data are listed in Table 1, Comparative Example 2.
[0086] Table 1. Performance of PI catalytic materials in producing hydrogen peroxide under different conditions.
[0087]
[0088] As can be seen from the data in Table 1, compared to the Kapton film in Comparative Example 1 and the absence of any catalyst in Comparative Example 2, the PI bifunctional photo / piezoelectric catalytic materials prepared by the solvothermal method in Examples 1-4 exhibit excellent photocatalytic and piezoelectric response performance, and the performance can be significantly improved when photo-piezoelectric is used simultaneously. Furthermore, compared to Examples 1 and 2, Examples 3 and 4, which introduce locally polar hydroxyl units into the structure, further enhance the photocatalytic performance, piezoelectric response performance, and catalytic performance when photo-piezoelectric is used simultaneously.
[0089] Therefore, the PI bifunctional photo / piezocatalytic material prepared by the solvothermal method proposed in this invention has excellent photocatalytic and piezocatalytic performance, and the preparation process is simple and the reaction is controllable. This implementation scheme has good industrialization prospects.
[0090] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.
Claims
1. A linear polyimide bifunctional photo / piezoelectric catalytic material, characterized in that, The linear polyimide is prepared from dianhydride and diamine as raw materials. The dianhydride is selected from at least one of pyromellitic dianhydride and biphenyl dianhydride, and the diamine is 3-hydroxy-4,4'-diaminobenzoylaniline. The molar ratio of the dianhydride to the diamine is 1:0.9-1.
1.
2. A method for preparing the linear polyimide bifunctional photo / piezoelectric catalytic material according to claim 1, characterized in that, Includes the following steps: 1) A non-protic strongly polar solvent and an alcohol solvent are mixed evenly to obtain a mixed solvent; 2) Dissolve the dianhydride in a mixed solvent, then add the diamine and stir to obtain a mixed solution; 3) The mixed solution is reacted at 160-200 ℃ to obtain the final product.
3. The preparation method according to claim 2, characterized in that, The aprotic strongly polar solvent mentioned in step 1) is selected from at least one of N,N-dimethylformamide, N-methylpyrrolidone and N,N-dimethylacetamide.
4. The preparation method according to claim 2, characterized in that, The alcohol solvent mentioned in step 1) is a polyol.
5. The preparation method according to claim 2, characterized in that, The volume ratio of the aprotic strongly polar solvent to the alcohol solvent in step 1) is 1:0.25-1.
5.
6. The preparation method according to claim 2, characterized in that, In step 2), the dianhydride and the diamine account for 10-25 wt% of the total reaction system.
7. The preparation method according to claim 2, characterized in that, The reaction time in step 3) is 36-50 h.
8. The application of the linear polyimide bifunctional photo / piezocatalytic material prepared by the preparation method of the linear polyimide bifunctional photo / piezocatalytic material according to claim 1 or any one of claims 2-7 in the fields of photocatalysis, piezocatalysis, or photo-piezo-co-catalytic technology, characterized in that, The applications include at least one of the following: degrading pollutants in water, preparing hydrogen peroxide, decomposing water to produce hydrogen, and reducing CO2 to carbon-containing fuels.