Composite piezoelectric catalytic material for sewage treatment as well as preparation and application of composite piezoelectric catalytic material

Abstract

The invention discloses a composite piezoelectric catalytic material for sewage treatment as well as preparation and application thereof, and belongs to the technical field of piezoelectric catalytic materials. The preparation method of the composite piezoelectric catalytic material comprises the following steps: dissolving a ferroelectric polymer and a polyester polymer in a polar solvent to obtain a polymer solution; adding iron oxide into the polymer solution, stirring, adding a solid water-soluble template, and stirring to obtain dispersion liquid; placing the dispersion liquid in a mold, and drying to obtain a material; and placing the material in water for 24-26h, washing and drying to obtain the composite piezoelectric catalytic material. In the preparation process of the composite piezoelectric catalytic material, under the combined action of the polyester polymer and the polar solvent, generation of a beta phase in the ferroelectric polymer can be promoted, and the Fenton effect of iron ions is induced based on the strong piezoelectric effect of the beta phase, so that the composite piezoelectric catalytic material is prepared. The composite catalytic material disclosed by the invention has the characteristics of high degradation efficiency, long service life and easiness in recovery.

Description

Technical Field

[0001] The present invention relates to the technical field of piezoelectric catalytic materials, and particularly relates to a composite piezoelectric catalytic material for sewage treatment, its preparation and application. Background Art

[0002] Piezoelectric catalytic materials are a new type of functional materials based on piezoelectric materials, which can perform piezoelectric catalytic degradation on organic pollutants in water bodies such as dyes, antibiotics, and pesticides. They have the characteristics of high degradation efficiency and environmental friendliness, and have important potential in the fields of pollutant treatment, energy conversion, etc. Among them, inorganic piezoelectric ceramics have the characteristics of high piezoelectric effect and good catalytic degradation effect, and have obvious performance advantages in the field of piezoelectric catalysis. However, inorganic powders are prone to cause secondary pollution to water bodies and are difficult to recycle, making it still face huge challenges in practical applications.

[0003] In comparison, ferroelectric polymers represented by polyvinylidene fluoride and its copolymers are a kind of flexible, weather-resistant, and easy-to-process functional polymer materials. Especially its β-phase crystal structure has typical piezoelectric characteristics, which can overcome the application defects of inorganic piezoelectric powders being prone to cause secondary pollution to water bodies and being difficult to recycle. However, the piezoelectric effect of ferroelectric polymers is relatively low, which limits the further development of polymer-based piezoelectric catalytic materials. In addition, the Fenton effect of iron oxides can also be applied to sewage treatment, but the Fenton effect of iron oxides will only appear under the condition of hydrogen peroxide, and the application range is narrow. Therefore, developing composite piezoelectric catalytic materials with high degradation performance has extremely strong practical value. Summary of the Invention

[0004] Aiming at the deficiencies of the above prior art, the present invention provides a composite piezoelectric catalytic material for sewage treatment, its preparation and application. The composite piezoelectric catalytic material of the present invention has a porous structure and a piezoelectric-Fenton synergistic catalytic system, and thus has the characteristics of high degradation efficiency, good piezoelectric performance, and easy recovery. At the same time, it is convenient for industrial production and has a very good application prospect. Specifically, it is achieved through the following technologies.

[0005] A preparation method of a composite piezoelectric catalytic material for sewage treatment, comprising the following steps:

[0006] Dissolve ferroelectric polymer and polyester polymer in a polar solvent to obtain a polymer solution;

[0007] Add iron oxide to the above polymer solution, stir, add a solid water-soluble template, and stir to obtain a dispersion;

[0008] Place the above dispersion in a mold and perform the first drying to obtain a material;

[0009] Place the above materials in water. After 24 - 26 h, wash and remove the solid water-soluble template, and then conduct the second drying to obtain the composite piezoelectric catalytic material.

[0010] Preferably, the mass ratio of the polyester polymer to the ferroelectric polymer is (0.05 - 0.1):1.

[0011] Preferably, the mass ratio of the iron oxide to the ferroelectric polymer is (0.3 - 1.2):1. Further preferably, the mass ratio of the iron oxide to the ferroelectric polymer is (0.9 - 1.1):1.

[0012] Preferably, the mass ratio of the polar solvent to the ferroelectric polymer is (8 - 12):1. Further preferably, the mass ratio of the polar solvent to the ferroelectric polymer is 10:1.

[0013] Preferably, the mass ratio of the solid water-soluble template to the ferroelectric polymer is (4 - 7):1.

[0014] Preferably, the polyester polymer includes at least one of polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc.

[0015] Preferably, the polar solvent includes at least one of N,N-dimethylformamide, dimethyl sulfoxide, and dimethylacetamide.

[0016] Preferably, the ferroelectric polymer includes at least one of polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyvinylidene fluoride-chlorotrifluoroethylene (PVDF-CTFE), and polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE).

[0017] Preferably, the iron oxide is at least one of iron(III) oxide or iron(II,III) oxide.

[0018] Preferably, the morphology of the iron oxide is any one of nanoparticles, nanosheets, or nanowires, where the particle size of the nanoparticles is 20 - 100 nm, the particle size of the nanosheets is 50 - 200 nm, and the particle size of the nanowires is 100 - 200 nm. Further preferably, the morphology of the iron oxide is nanosheets with a particle size of 100 nm.

[0019] Preferably, the solid water-soluble template includes at least one of table salt or granulated sugar.

[0020] Preferably, the temperature of the first drying is 50 - 70 °C, and the time is 12 - 24 h. Further preferably, the temperature of the first drying is 60 °C, and the time is 12 h.

[0021] Preferably, the particle size of the solid water-soluble template is 20 - 200 μm.

[0022] The present invention provides a composite piezoelectric catalytic material prepared by any one of the above preparation methods.

[0023] Preferably, the thickness of the above composite piezoelectric catalytic material is 0.1 - 1 mm. More preferably, the thickness of the above composite piezoelectric catalytic material is 0.25 - 0.5 mm.

[0024] The present invention also provides an application of the above composite piezoelectric catalytic material in treating organic pollutants in water bodies.

[0025] Compared with the prior art, the advantages of the present invention are as follows:

[0026] (1) The composite piezoelectric catalytic material of the present invention has a piezoelectric-Fenton piezoelectric catalytic system, which can greatly improve the degradation efficiency of organic pollutants in water bodies such as dyes, antibiotics, and pesticides, and solves the defect of low piezoelectric catalytic efficiency of single ferroelectric polymers.

[0027] (2) In the process of preparing the composite piezoelectric catalytic material of the present invention, under the synergistic action of polyester polymers and polar solvents, the formation of more β phases in the ferroelectric polymer is promoted, and the piezoelectric properties of the ferroelectric polymer substrate are improved; at the same time, the piezoelectric effect of the ferroelectric polymer can induce the Fenton effect of iron ions, thereby forming a piezoelectric-Fenton synergistic catalytic system to improve the degradation efficiency; through the reasonable selection of the particle size and ratio of the solid water-soluble template, the pore size, porosity, and specific surface area of the composite piezoelectric catalytic material are regulated, and the precise design of the porous structure in the composite piezoelectric catalytic material is realized.

[0028] (3) The composite piezoelectric catalytic material of the present invention can be directly inserted into the water to be treated during use, and can also be directly taken out after the catalytic degradation is completed, overcoming the defect of difficult recovery of traditional inorganic piezoelectric powders. That is, the composite piezoelectric catalytic material of the present invention not only has high catalytic degradation efficiency, but also is convenient to use, simple to recover, and will not cause secondary pollution to the water body. Description of the Drawings

[0029] Figure 1 SEM image of the composite piezoelectric catalytic material of Example 1;

[0030] Figure 2 Optical picture of the composite piezoelectric catalytic material of Example 1;

[0031] Figure 3 X-ray diffraction pattern (a) and Fourier transform infrared spectrum (b) of the composite piezoelectric catalytic material of Example 1;

[0032] Figure 4 SEM picture of iron oxide nanosheets in the present invention;

[0033] Figure 5Optical photograph of the degradation of Rhodamine B dye by the composite piezoelectric catalytic material of Example 1;

[0034] Figure 6 Graph of the degradation rate data of the composite piezoelectric catalytic material of Example 1 for five pollutants: Rhodamine B (RhB), Methylene Blue (MB), Alizarin Red (AR), Methyl Orange (MO), and Tetracycline (TC);

[0035] Figure 7 Graph of the β-phase content comparison of PMMA and PVDF with different mass ratios in the present invention;

[0036] Figure 8 Graph of the β-phase content comparison using different solvents in the present invention;

[0037] Figure 9 In (a - e), they are respectively schematic diagrams of the change in the degradation efficiency of RhB with time by the composite piezoelectric catalytic materials prepared in Examples 1 - 5. Detailed implementation mode

[0038] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below in combination with examples, but they cannot be understood as limiting the protection scope of the present invention.

[0039] The present invention also provides a preparation method of a composite piezoelectric catalytic material, including the following steps:

[0040] Dissolve a ferroelectric polymer and polymethyl methacrylate in a polar solvent to obtain a polymer solution;

[0041] Add iron oxide to the above polymer solution, stir, add a solid water-soluble template, and stir to obtain a dispersion;

[0042] Place the above dispersion in a mold and perform the first drying to obtain a material;

[0043] Place the above material in water to dissolve the solid water-soluble template. After 24 - 26 hours, wash and remove the solid water-soluble template, and perform the second drying to obtain the composite piezoelectric catalytic material.

[0044] Optionally, the mass ratio of the polyester polymer to the ferroelectric polymer is (0.05 - 0.1):1.

[0045] Optionally, the mass ratio of the iron oxide to the ferroelectric polymer is (0.3 - 1.2):1.

[0046] Optionally, the thickness of the above composite piezoelectric catalytic material is 0.1 - 1 mm. Further optionally, the thickness of the above composite piezoelectric catalytic material is 0.25 - 0.5 mm.

[0047] Optionally, the polyester polymer is any one of polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc.

[0048] Optionally, the ferroelectric polymer is any one of polyvinylidene fluoride (PVDF), polyvinylidene fluoride - hexafluoropropylene (PVDF - HFP), polyvinylidene fluoride - chlorotrifluoroethylene (PVDF - CTFE), and polyvinylidene fluoride - trifluoroethylene (PVDF - TrFE).

[0049] Optionally, the iron oxide is at least one of iron(III) oxide or iron(II,III) oxide.

[0050] Optionally, the morphology of the iron oxide is any one of nanoparticles, nanosheets, or nanowires, where the particle size of the nanoparticles is 20 - 100 nm, the particle size of the nanosheets is 50 - 200 nm, and the particle size of the nanowires is 100 - 200 nm. Further optionally, the morphology of the iron oxide is nanosheets with a particle size of 100 nm.

[0051] Optionally, the polar solvent is any one of N,N - dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and dimethylacetamide (DMAC).

[0052] Optionally, the mass ratio of the polar solvent to the ferroelectric polymer is (8 - 12):1. Further optionally, the mass ratio of the polar solvent to the ferroelectric polymer is 10:1.

[0053] Optionally, the mass ratio of the solid water - soluble template to the ferroelectric polymer is (4 - 7):1.

[0054] Optionally, the solid water - soluble template is any one of table salt or granulated sugar.

[0055] Optionally, the particle size of the solid water - soluble template is 20 - 200 μm.

[0056] Optionally, the temperature of the first drying is 50 - 70 °C and the time is 12 - 24 h. Further optionally, the temperature of the first drying is 60 °C and the time is 12 h.

[0057] The technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0058] The SEM images of the iron(III) oxide nanosheets used in the present invention are as follows Figure 4 shown.

[0059] Example 1

[0060] This example provides a method for preparing a composite piezoelectric catalytic material, including the following steps:

[0061] S1. Dissolve 1 g of PVDF and 0.1 g of polymethyl methacrylate in 10 g of N,N-dimethylformamide (DMF) to obtain a polymer solution;

[0062] S2. Add 1 g of iron oxide nanosheets with a particle size of 100 nm to the polymer solution in step S1, stir until completely dispersed, add 5 g of salt, and stir until completely dispersed to obtain a dispersion;

[0063] S3. Place the dispersion in step S2 in a mold, dry it at 60 °C for 12 h until the DMF is completely evaporated to obtain a material;

[0064] S4. Place the material in step S3 in distilled water. After 24 h, the salt is completely dissolved, washed, and dried at 60 °C for 12 h to obtain the composite piezoelectric catalytic material.

[0065] The SEM image of the composite piezoelectric catalytic material in this example is as follows Figure 1 shown. It can be seen from Figure 1 that the surface of the composite piezoelectric catalytic material prepared in this example has fine pores.

[0066] The optical image of the composite piezoelectric catalytic material in this example is as follows Figure 2 shown. It can be seen from Figure 2 that the composite piezoelectric material prepared in this example has a film structure rather than a powder structure. When in use, it can be directly placed in the water body to be treated and directly taken out after the catalytic degradation is completed, without causing secondary pollution to the water body.

[0067] The X-ray diffraction pattern (a) and Fourier transform infrared spectrum (b) of the composite piezoelectric catalytic material in this example are as follows Figure 3 shown. It can be seen from Figure 3 that the composite piezoelectric material prepared in this example has more β-phase structures.

[0068] The optical photo of the degradation of Rhodamine B (RhB) dye by the composite piezoelectric catalytic material in this example is as follows Figure 5 shown. It can be seen from Figure 5 that the composite piezoelectric catalytic material in Example 1 has obvious degradation of RhB at 10 minutes, and the degradation is basically completed at 30 minutes, indicating that the composite piezoelectric catalytic material of the present invention has a very high degradation efficiency.

[0069] The degradation rate data graphs of the composite piezoelectric catalytic material of this embodiment for five pollutants, namely rhodamine B (RhB), methylene blue (MB), alizarin red (AR), methyl orange (MO), and tetracycline (TC), are as follows Figure 6 As shown, from Figure 6 it can be seen that the degradation rates of the composite piezoelectric catalytic material of Example 1 for these five pollutants are all above 59%. Among them, the degradation rates for rhodamine B (RhB) and methylene blue (MB) are the highest, exceeding 95%. This indicates that the composite piezoelectric catalytic material of the present invention has a good degradation effect on various pollutants.

[0070] Example 2

[0071] This embodiment provides a preparation method of a composite piezoelectric catalytic material, including the following steps:

[0072] S1. Dissolve 1 g of PVDF-CTFE and 0.05 g of PET in 8 g of dimethyl sulfoxide (DMSO) to obtain a polymer solution;

[0073] S2. Add 0.3 g of iron oxide nanosheets with a particle size of 100 nm to the polymer solution in step S1, stir until completely dispersed, add 4 g of table salt, and stir until completely dispersed to obtain a dispersion;

[0074] S3. Place the dispersion in step S2 in a mold, dry it at 50 °C for 16 h until DMF is completely evaporated to obtain a material;

[0075] S4. Place the material in step S3 in distilled water. After 25 h, the table salt is completely dissolved, wash it, and dry it at 60 °C for 12 h to obtain the composite piezoelectric catalytic material.

[0076] Example 3

[0077] This embodiment provides a preparation method of a composite piezoelectric catalytic material, including the following steps:

[0078] S1. Dissolve 1 g of PVDF-HFP and 0.1 g of PBT in 12 g of dimethyl sulfoxide (DMSO) to obtain a polymer solution;

[0079] S2. Add 1.2 g of iron oxide nanosheets with a particle size of 100 nm to the polymer solution in step S1, stir until completely dispersed, add 7 g of table salt, and stir until completely dispersed to obtain a dispersion;

[0080] S3. Place the dispersion in step S2 in a mold, dry it at 70 °C for 24 h until DMF is completely evaporated to obtain a material;

[0081] S4. Place the material obtained in step S3 in distilled water. After 24 h, the salt is completely dissolved. Wash it and then dry it at 60 °C for 12 h to obtain the composite piezoelectric catalytic material.

[0082] Example 4

[0083] This example provides a method for preparing a composite piezoelectric catalytic material, which is basically the same as that in Example 1, except that the mass of iron(III) oxide in step S2 is 0.9 g.

[0084] Example 5

[0085] This example provides a method for preparing a composite piezoelectric catalytic material, which is basically the same as that in Example 1, except that the mass of iron(III) oxide in step S2 is 1.1 g.

[0086] Comparative Example 1

[0087] This comparative example provides a method for preparing a composite material, which is basically the same as that in Example 1, except that polymethyl methacrylate (PMMA) is not used in step S1.

[0088] Comparative Example 2

[0089] This comparative example provides a method for preparing a composite piezoelectric catalytic material, which is basically the same as that in Example 1, except that iron(III) oxide is not used in step S2.

[0090] Comparative Example 3

[0091] This comparative example provides a method for preparing a composite piezoelectric catalytic material, which is basically the same as that in Example 1, except that PVDF is not used in step S1.

[0092] Comparative Example 4

[0093] This comparative example provides a method for preparing a composite piezoelectric catalytic material, which is basically the same as that in Example 1, except that the drying temperature in step S3 is 48 °C.

[0094] Comparative Example 5

[0095] This comparative example provides a method for preparing a composite piezoelectric catalytic material, which is basically the same as that in Example 1, except that the drying temperature in step S3 is 73 °C.

[0096] Test Example

[0097] 1. Determination of β-phase content:

[0098] Use a Fourier transform infrared spectrometer to measure the composite piezoelectric catalytic materials of Examples 1-5 and Comparative Examples 1-5 in equal amounts. Characteristic peaks of different crystal structures can be detected. Among them, the characteristic peak of the α-phase is at 764 cm-1 , the characteristic peak of the β phase is at 840 cm -1 . The proportion of the β phase is calculated according to the following formula: F(β) = A(β) / (1.26A(α)+A(β)). Here, A(α) and A(β) respectively represent the integral areas of the characteristic peaks at 764 cm -1 and 840 cm -1 . The measurement results are shown in Table 1 below.

[0099] Table 1 Measurement of the β phase in Examples 1-5 and Comparative Examples 1-5

[0100]

[0101]

[0102] As can be seen from Table 1, the content of the β phase in Examples 1-5 is all above 80%, which indicates that the composite piezoelectric catalytic material prepared by the preparation method of the present invention has strong piezoelectric properties.

[0103] Compared with Example 1, the content of the β phase in Comparative Example 1 and Comparative Examples 3-5 has decreased significantly. This is because PMMA was not used in Comparative Example 1, so the PVDF molecular chains could not generate higher internal stress during the preparation process, that is, PVDF could not generate more β phase. Therefore, the content of the β phase in Comparative Example 1 is extremely low; PVDF was not used in Comparative Example 3, so there is no β phase. Therefore, the content of the β phase in Comparative Example 3 is 0; in Comparative Examples 4-5, the drying temperature in step S3 was used outside the range, and the crystallization process of PVDF can only be carried out within an appropriate temperature range. Therefore, the content of the β phase in Comparative Examples 4-5 is also low.

[0104] The applicant of the present invention also set up five groups of comparative experiments. The mass ratio of PMMA to PVDF in each group of composite piezoelectric catalytic materials is 0.01:1, 0.05:1, 0.1:1, 0.15:1, 0.2:1 respectively. The preparation method of each group of composite piezoelectric catalysis is the same as that of Example 1. The β phase content of each group of prepared composite piezoelectric catalysis was measured, and the measurement results are as Figure 7 shown.

[0105] From Figure 7 it can be seen that when the mass ratio of PMMA to PVDF is set at (0.05-0.1):1, the content of the β phase ≥ 80%, and when it exceeds the above range, the content of the β phase ≤ 65%. This indicates that the mass ratio of PMMA to PVDF is also crucial.

[0106] The applicant of the present invention also set up three groups of verification tests. The preparation methods of the composite piezoelectric catalytic materials in the three groups of verification tests are basically the same as those in Example 1, except that the solvents in the three groups are DMF, DMAC, and DMSO respectively. The β-phase content of the composite piezoelectric catalytic materials prepared in the three groups was measured, and the measurement results are as Figure 8 shown.

[0107] It can be seen from Figure 8 that the content of the β-phase in the three groups is ≥78%, which indicates that the three solvents of DMF, DMAC, and DMSO can all be used to prepare the composite piezoelectric catalytic material of the present invention.

[0108] 2. Degradation degree measurement:

[0109] The degradation degree refers to the ratio of the concentration of the pollutant after degradation to the original concentration, that is, the degradation degree = Ct / C0. In actual experiments, the degradation degree is calculated through the ultraviolet spectrum. According to the Lambert-Beer law, A = εCL, where A is the absorbance of the ultraviolet spectrum, C is the concentration, and ε and L are both constants. At this time, Ct / C0 = At / A0.

[0110] The degradation degree test was carried out according to the following method: Weigh 0.1 g of each of the composite piezoelectric materials prepared in Examples 1-5 and Comparative Examples 1-5, and put them into brown reagent bottles containing 50 ml of aqueous solutions of rhodamine B (RhB) or tetracycline (TC) with a concentration of 5 ppm each, and let them stand for 12 h in the dark to reach the adsorption equilibrium. Then, place the brown reagent bottles in a water bath ultrasonic device with a power of 300 W, and after ultrasonic treatment for 1 h, calculate the degradation degree of rhodamine B (RhB) or tetracycline (TC) by the above method. The piezoelectric catalytic degradation test of pollutants was carried out on the composite piezoelectric catalytic materials prepared in Examples 1-5 and Comparative Examples 1-5. The results are shown in Table 2 below.

[0111] Table 2 Degradation degrees of Examples 1-5 and Comparative Examples 1-5

[0112]

[0113] It can be seen from Table 2 that the degradation degrees of RhB and TC in Examples 1-5 can be as low as 0.05 and 0.37 respectively, which indicates that the composite piezoelectric catalytic material of the present invention has a high degradation efficiency.

[0114] Compared with Example 1, the degradation degrees of RhB and TC in Comparative Examples 1-5 all decreased. This is because PMMA was not used in Comparative Example 1, resulting in a decrease in the content of the β-phase generated by PVDF and an inability to fully stimulate the Fenton effect of iron ions. Therefore, the degradation degree of Comparative Example 1 decreased. In Comparative Example 2, iron oxide was not used, and there was no Fenton effect. Pollutants were degraded only through the piezocatalytic effect of PVDF. Therefore, the degradation degree of Comparative Example 2 decreased significantly. In Comparative Example 3, PVDF was not used, there was neither the β-phase nor the ability to stimulate the Fenton effect of iron ions. Therefore, the degradation degree of Comparative Example 3 was extremely low. In steps S3 of Comparative Examples 4-5, the drying temperature was used outside the specified range. Similar to Comparative Example 1, the content of the β-phase generated by PVDF decreased, and at the same time, the Fenton effect of iron ions could not be fully stimulated. Therefore, the degradation degrees of Comparative Examples 4-5 decreased.

[0115] As can be comprehensively seen from Table 1-2, in the preparation process of the composite piezocatalytic material of the present invention, through the synergistic effect of polyester polymers and polar solvents, the generation of more β-phases in ferroelectric polymers is promoted, and the piezoelectric properties of ferroelectric polymer substrates are improved; at the same time, the piezoelectric effect of ferroelectric polymers can induce the Fenton effect of iron ions, thereby forming a piezoelectric-Fenton synergistic catalytic system, which better improves the degradation efficiency of the material.

[0116] The applicant of the present invention conducted an experiment on the change of the degradation degree of rhodamine B (RhB) with time for the composite piezocatalytic materials prepared in Examples 1-5. The test results are as follows Figure 9 (a-e) shows, where the ordinate C / C0 represents the comparison of the RhB concentration with the original RhB concentration, that is, the degradation degree of RhB. From Figure 9 (a-e), it can be seen that the time taken for the composite piezocatalytic materials prepared in Examples 1-5 to degrade RhB was all within 100 min, and the minimum could be as low as 60 min. This shows that the composite piezocatalytic material prepared by the present invention has a very high degradation efficiency and can quickly degrade pollutants such as dyes.

[0117] The above specific embodiments have described the implementation of the present invention in detail. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solutions of the present invention, and these simple variations all belong to the protection scope of the present invention.

Claims

1. A preparation method of a composite piezoelectric catalytic material for sewage treatment, characterized in that, It includes the following steps: Dissolve a ferroelectric polymer and a polyester polymer in a polar solvent to obtain a polymer solution; Add iron oxide to the polymer solution, stir, add a solid water-soluble template, and stir to obtain a dispersion; Place the dispersion in a mold and conduct the first drying to obtain a material; Place the material in water, after 24 - 26 h, wash and remove the solid water-soluble template, and conduct the second drying to obtain the composite piezoelectric catalytic material.

2. The preparation method according to claim 1, wherein The mass ratio of the polyester polymer to the ferroelectric polymer is (0.05 - 0.1):

1.

3. The preparation method according to claim 1, characterized in that, The mass ratio of the iron oxide to the ferroelectric polymer is (0.3 - 1.2):

1.

4. The preparation method according to claim 3, wherein The mass ratio of the iron oxide to the ferroelectric polymer is (0.9 - 1.1):

1.

5. The preparation method according to claim 1, characterized in that, The polyester polymer includes at least one of polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, etc.

6. The preparation method according to claim 1, wherein The polar solvent includes at least one of N,N-dimethylformamide, dimethyl sulfoxide, and dimethylacetamide.

7. The preparation method according to claim 1, characterized in that, The temperature of the first drying is 50 - 70 °C, and the time is 12 - 24 h.

8. The preparation method according to claim 1, characterized in that, The particle size of the solid water-soluble template is 20 - 200 μm.

9. The composite piezoelectric catalytic material prepared by the preparation method according to any one of claims 1 - 8.

10. The application of the composite piezoelectric catalytic material according to claim 9 in treating organic pollutants in water bodies.

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