Piezoelectric catalytic material and preparation method thereof

Abstract

The application discloses a piezoelectric catalytic material and a preparation method thereof, and particularly relates to the field of piezoelectric catalytic materials, and comprises a flexible piezoelectric base component, a polarization enhancement component, a free radical activation and electron capture component and a film forming component; by constructing a composite system of synergistically enhanced flexible polymer matrix and high polarization functional filler, the piezoelectric catalytic activity of the material is improved, and the response ability to low-frequency mechanical energy is enhanced, so as to solve the problems of the existing inorganic piezoelectric ceramic, such as large brittleness and insufficient flexibility, and the existing PVDF material, such as low natural polarization phase content and weak carrier migration ability, which result in low catalytic efficiency and insufficient energy conversion; the material exhibits excellent mechanical energy to chemical energy conversion ability under the condition of low-frequency water flow and other natural mechanical excitation, and realizes efficient catalytic degradation of organic pollutants, has good environmental adaptability and stability, and can meet the actual application requirements of flexible, durable and self-powered catalytic materials in the fields of green energy recovery and environmental governance.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric catalytic materials technology, and more specifically, to a piezoelectric catalytic material and its preparation method. Background Technology

[0002] In the field of piezoelectric catalysis, existing technologies mainly rely on inorganic piezoelectric ceramic materials. Although they have high piezoelectric performance and energy conversion efficiency, their inherent brittleness, low flexibility, and processing difficulty make the materials have obvious limitations in complex mechanical environments and flexible structure applications, making it difficult to meet the requirements for material stability and adaptability in low-frequency energy scenarios such as actual water treatment.

[0003] To overcome the rigidity of inorganic materials, flexible polymer materials, especially polyvinylidene fluoride (PVDF), have been proposed as an alternative due to their lightweight, good flexibility, and strong biocompatibility. However, existing PVDF materials are limited by insufficient content of the natural polarized β phase, low piezoelectric properties, and limited carrier migration ability, resulting in catalytic efficiency and energy conversion capacity that are far from meeting the requirements of practical applications under natural environmental energy-driven conditions such as low-frequency vibration or water flow.

[0004] At the same time, current piezoelectric catalytic systems mostly rely on high-frequency mechanical energy driving methods such as ultrasonic vibration, which is significantly mismatched with the low-frequency, low-energy mechanical excitation that is prevalent in the environment, thus limiting the potential of piezoelectric catalytic technology in the engineering application of green energy recovery and environmental pollution control.

[0005] Based on the current state of development and limitations of existing technologies, it can be seen that how to further improve piezoelectric catalytic activity and enhance the response to low-frequency mechanical energy while achieving material flexibility has become a key issue restricting the practical application of piezoelectric catalysis technology. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a piezoelectric catalytic material and its preparation method. By constructing a composite system synergistically enhanced by a flexible polymer matrix and a highly polarized functional filler, the piezoelectric catalytic activity and low-frequency mechanical energy response capability are improved, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a piezoelectric catalytic material, comprising a composite system of the following components in the indicated weight ratios:

[0008] The flexible piezoelectric matrix component, in parts by weight of 80-120, is used to construct a flexible framework and provide a basic piezoelectric response.

[0009] The polarization enhancement component, in parts by weight of 20-40, is used to enhance the interfacial polarization effect and improve carrier migration efficiency.

[0010] The radical activating and electron capturing component, in parts by weight of 5-15, is used to promote the generation of free radicals and optimize electron capturing channels.

[0011] The film-forming component, in parts by weight of 5-15, is used to optimize the film-forming properties and environmental stability of the composite material.

[0012] In a preferred embodiment, the flexible piezoelectric matrix component is configured in the following weight ratios:

[0013] Polyvinylidene fluoride (PVDF), 95 parts, wherein the crystallinity of the β phase is not less than 70%, the molecular weight is in the range of 400,000–600,000 g / mol, and the melting point is in the range of 160–170℃;

[0014] Polyvinylpyrrolidone (PVP), 3 parts, with a molecular weight of 40,000–60,000 g / mol, is used to enhance the orientation of polarized segments;

[0015] Fluorinated polyacrylate (FPAA), 2 parts, with an average particle size of less than 100 nm, is used to optimize tensile strength.

[0016] In a preferred embodiment, the polarization-enhancing component is configured in the following weight ratios:

[0017] Iron oxide (Fe3O4) nanoparticles, 50 parts, with a particle size controlled at 50–80 nm and a magnetic saturation strength of not less than 60 emu / g;

[0018] Bismuth ferrite (BiFeO3) nanoparticles, 25 parts, monoclinic crystal form, with a particle size of 40–60 nm, exhibit anti-ferroelectric properties and a dielectric constant (relative dielectric constant) higher than 300;

[0019] Molybdenum disulfide (MoS2) sheets, 15 parts, with a layer thickness of less than 10 nm, a lateral dimension of more than 500 nm, and an electrical conductivity of more than 500 S / cm;

[0020] Ten parts of Ti3C2MXene sheet material, with a thickness of 2–5 nm, an interlayer spacing of not less than 1 nm, and a specific surface area greater than 100 m². 2 / g;

[0021] Aminosilane (KH-550) surface modifier, added at 3% of the total weight of inorganic components, is used to improve the uniformity of filler dispersion and interfacial bonding strength in the polymer matrix.

[0022] In a preferred embodiment, the radical activating and electron-capturing component is configured in the following weight ratios:

[0023] Graphitic carbon nitride (g-C3N4), 50 parts, with a sheet thickness of 5–10 nm and a specific surface area greater than 60 m². 2 / g, C / N molar ratio controlled at 0.65–0.7;

[0024] Nitrogen-doped graphene (N-Graphene), 30 parts, with nitrogen doping concentration of 5–8 at%, sheet thickness less than 5 nm, and surface charge mobility greater than 1000 cm⁻¹. 2 / V·s;

[0025] Molybdenum disulfide (MoS2), 20 parts, crystallinity greater than 90%, electron migration rate greater than 200 cm⁻¹ 2 / V·s, and has van der Waals heterojunction structure characteristics.

[0026] In a preferred embodiment, the film-forming component is prepared in the following weight ratio:

[0027] Waterborne polyurethane (PU) dispersion, 70 parts, solid content controlled at 30±2wt%, particle size less than 80nm;

[0028] Irganox 1010 antioxidant, 20 parts, thermal decomposition temperature above 350℃, with free radical scavenging capacity greater than 90%;

[0029] Dioctyl phthalate (DOP), 10 parts, with a molecular weight in the range of 390–410 g / mol and a boiling point above 380℃, is used to regulate the interaction forces between chain segments within the material and adjust the Young's modulus to the range of 100–300 MPa.

[0030] A method for preparing a piezoelectric catalytic material:

[0031] S1: Preparation of flexible piezoelectric matrix precursor solution:

[0032] Polyvinylidene fluoride (PVDF), polyvinylpyrrolidone (PVP), and fluorinated polyacrylate (FPAA) were mixed in a weight ratio of 95:3:2 and added to N,N-dimethylformamide (DMF) to control the mass fraction of the solution at 10–15%. The solution was then magnetically stirred at room temperature for 360 minutes until no visible precipitate was observed, thus obtaining the precursor solution.

[0033] S2: Preparation of polarization-enhanced composite component dispersion:

[0034] Iron oxide (Fe3O4) nanoparticles, bismuth ferrite (BiFeO3) nanoparticles, molybdenum disulfide (MoS2) sheets, and Ti3C2MXene sheets were mixed in a weight ratio of 50:25:15:10, added to anhydrous ethanol, and 3% of aminosilane (KH-550) surface modifier (total inorganic components) was added. The mixture was then ultrasonically treated for 1800 seconds to complete dispersion.

[0035] S3: Preparation of dispersion of free radical activation and electron capture composite components:

[0036] Graphitic carbon nitride (g-C3N4), nitrogen-doped graphene (N-Graphene), and molybdenum disulfide (MoS2) were mixed in a weight ratio of 50:30:20, added to isopropanol, and ultrasonically treated for 3600 seconds to complete dispersion.

[0037] S4: Preparation of film-forming aid dispersion:

[0038] A water-based polyurethane (PU) dispersion, Irganox 1010 antioxidant, and dioctyl phthalate (DOP) were mixed in a weight ratio of 70:20:10, and a water-alcohol mixed solvent was added. The mixture was mechanically stirred for 240 minutes to prepare a film-forming aid dispersion.

[0039] S5: Preparation of composite piezoelectric catalytic slurry:

[0040] The flexible piezoelectric matrix precursor solution, polarization-enhanced composite component dispersion, free radical activation and electron capture composite dispersion, and film-forming aid dispersion are mixed according to a preset weight ratio, added to a high-speed disperser, and stirred at 500 rpm for 300 minutes. After completion, the mixture is placed under vacuum conditions with a pressure not exceeding -0.1 MPa for 60 minutes to degas and obtain the composite slurry.

[0041] In a preferred embodiment, S6: Film forming and drying:

[0042] The composite piezoelectric catalytic slurry was coated onto the surface of the pretreated substrate using a spin coating method. The spin coating speed was set to 1000–3000 rpm and the spin coating time was set to 30–60 seconds. After spin coating, the sample was placed in a vacuum oven and dried at 80°C for 120 minutes. Then, the temperature was raised to 120°C and dried for another 480 minutes to prepare a dried piezoelectric catalytic film.

[0043] In a preferred embodiment, S7: Polarization treatment:

[0044] The dried piezoelectric catalytic film was placed in a high-voltage polarization device, a DC electric field of 5–10 kV / cm was applied, the polarization temperature was controlled at 80–100℃, and the polarization time was set to 1800 seconds to complete the polarization treatment.

[0045] S8: Membrane peeling and collection:

[0046] The polarized piezoelectric catalytic membrane is peeled off from the substrate surface, cooled to room temperature, and cut to the required size to obtain the finished piezoelectric catalytic membrane.

[0047] The technical effects and advantages of this invention are as follows:

[0048] 1. This invention constructs a flexible PVDF-based piezoelectric catalytic material and combines it with a Fe3O4, BiFeO3 and MXene multi-component composite system to enhance the material's response to low-frequency mechanical energy, thus solving the problems of high brittleness, insufficient flexibility and poor environmental adaptability of existing inorganic piezoelectric materials.

[0049] 2. By introducing highly polarized fillers and regulating the crystallinity of the β phase, the carrier migration efficiency is improved, the internal charge separation is enhanced, the free radical generation capacity in the piezoelectric catalytic reaction is significantly improved, and the efficient degradation of water pollutants is promoted.

[0050] 3. A composite structure is constructed by synergistically using a flexible polymer matrix and inorganic functional particles, which takes into account both mechanical flexibility and electrical stability, and achieves stable catalytic degradation effect under environmental excitation conditions such as low-frequency water flow.

[0051] 4. By optimizing the film-making process and polarization treatment steps, the surface density and adhesion of the film layer are improved, the risk of film peeling and mechanical fatigue in the working environment is reduced, and the long-term reliability of the material is enhanced.

[0052] 5. Design a free radical activation and electron capture composite component to enhance the electron transfer process in the reaction pathway, effectively control the toxicity level of degradation intermediates, and promote the green and safe reaction process. Attached Figure Description

[0053] Figure 1 This is a flowchart of the preparation method of the present invention. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] Refer to the instruction manual appendix Figure 1 The present invention provides a piezoelectric catalytic material and its preparation method, comprising:

[0056] Example 1: This example describes the preparation of piezoelectric catalytic materials according to the following steps:

[0057] S1: Preparation of flexible piezoelectric matrix precursor solution:

[0058] Take 95 parts of polyvinylidene fluoride (PVDF), wherein the β-phase crystallinity of the PVDF is not less than 70%, the molecular weight is in the range of 400,000–600,000 g / mol, and the melting point is 160–170℃; take 3 parts of polyvinylpyrrolidone (PVP), wherein the molecular weight of polyvinylpyrrolidone (PVP) is 40,000–60,000 g / mol; take 2 parts of fluorinated polyacrylate (FPAA), wherein the average particle size of the FPAA is less than 100 nm.

[0059] The above components were mixed in a weight ratio of 95:3:2 and added to N,N-dimethylformamide (DMF) to control the mass fraction of the solution to be 10–15%.

[0060] At room temperature (25±2℃), the solution was stirred at 500 rpm for 360 minutes with a magnetic stirrer until the solution was clear and there was no visible precipitate, thus obtaining a flexible piezoelectric matrix precursor solution.

[0061] S2: Preparation of polarization-enhanced composite component dispersion:

[0062] Take 50 parts of iron oxide (Fe3O4) nanoparticles with a particle size controlled at 50–80 nm and a magnetic saturation strength of not less than 60 emu / g; take 25 parts of bismuth ferrite (BiFeO3) nanoparticles, monoclinic crystal type, with a particle size of 40–60 nm, exhibiting anti-ferroelectric properties and a relative permittivity higher than 300; take 15 parts of molybdenum disulfide (MoS2) sheets with a layer thickness of less than 10 nm, a lateral dimension greater than 500 nm, and an electrical conductivity higher than 500 S / cm; take 10 parts of Ti3C2MXene sheet material with a thickness of 2–5 nm, an interlayer spacing of not less than 1 nm, and a specific surface area greater than 100 m². 2 / g;

[0063] The above components are mixed in anhydrous ethanol at a weight ratio of 50:25:15:10, and then aminosilane (KH-550) surface modifier is added. The amount of KH-550 added is 3% of the total weight of the inorganic components.

[0064] A polarization-enhanced composite component dispersion was prepared by ultrasonic treatment with a frequency of 40kHz, a power of 500W, and a treatment time of 1800 seconds.

[0065] S3: Preparation of dispersion of free radical activation and electron capture composite components:

[0066] Take 50 parts of graphitic carbon nitride (g-C3N4), with a sheet thickness of 5–10 nm and a specific surface area greater than 60 m². 2 / g, C / N molar ratio controlled at 0.65–0.7; 30 parts of nitrogen-doped graphene (N-Graphene) with nitrogen doping amount of 5–8 at%, sheet thickness less than 5 nm, and surface charge mobility higher than 1000 cm⁻¹. 2 / V·s; Take 20 parts of molybdenum disulfide (MoS2), with a crystallinity greater than 90% and an electron migration rate greater than 200 cm⁻¹. 2 / V·s, and has van der Waals heterojunction structure characteristics;

[0067] The above components were mixed in a weight ratio of 50:30:20 and added to isopropanol. The mixture was then treated with ultrasound at a frequency of 40kHz, a power of 500W, and a treatment time of 3600 seconds to obtain a free radical activation and electron capture composite dispersion.

[0068] S4: Preparation of film-forming aid dispersion:

[0069] Take 70 parts of an aqueous polyurethane (PU) dispersion, wherein the PU solid content is controlled at 30±2% by mass and the particle size is less than 80nm; take 20 parts of Irganox1010 antioxidant, wherein the thermal decomposition temperature of Irganox1010 is higher than 350℃ and the free radical scavenging ability is greater than 90%; take 10 parts of dioctyl phthalate (DOP), wherein the molecular weight of DOP is in the range of 390–410 g / mol and the boiling point is higher than 380℃;

[0070] The above components were mixed in a weight ratio of 70:20:10 and added to a water-alcohol (mass ratio 1:1) mixed solvent. The mixture was stirred at 400 rpm for 240 minutes using a mechanical stirrer to obtain a film-forming aid dispersion.

[0071] S5: Preparation of composite piezoelectric catalytic slurry:

[0072] The flexible piezoelectric matrix precursor solution, the polarization-enhanced composite component dispersion, the free radical activation and electron capture composite dispersion, and the film-forming aid dispersion were mixed in a weight ratio of 100:30:10:10.

[0073] Using a high-speed disperser, the mixture was stirred at 500 rpm for 300 minutes. After stirring, the slurry was placed in a vacuum drying oven and degassed for 60 minutes under a pressure of -0.1 MPa to obtain the composite piezoelectric catalytic slurry.

[0074] S6: Film Forming and Drying:

[0075] The composite piezoelectric catalytic slurry was coated onto the cleaned and dried polyester substrate surface using a spin coating method. The spin coating speed was set to 2000 rpm and the spin coating time was set to 45 seconds.

[0076] After spin coating, the film was placed in a vacuum oven and dried at 80°C for 120 minutes. Then the temperature was raised to 120°C and dried for another 480 minutes to obtain a dry piezoelectric catalytic film.

[0077] S7: Polarization treatment:

[0078] The dried piezoelectric catalytic film was placed in a high-voltage polarization device, and a DC electric field was applied. The electric field strength was set to 7 kV / cm, the polarization temperature was set to 90℃, and the polarization time was set to 1800 seconds to complete the polarization treatment.

[0079] S8: Membrane peeling and collection:

[0080] The polarized piezoelectric catalytic membrane was peeled off from the substrate surface, cooled to room temperature, and cut into 50mm×50mm sizes to obtain the finished piezoelectric catalytic membrane material.

[0081] Example 2:

[0082] Based on Example 1, the weight parts of the flexible piezoelectric matrix component, polarization enhancement component, free radical activation and electron capture component, and film-forming component were adjusted to 80 parts, 20 parts, 5 parts, and 5 parts, respectively.

[0083] The selection of other components, component performance parameters, preparation process flow and process parameters are the same as in Example 1.

[0084] Example 3:

[0085] Based on Example 1, the weight parts of the flexible piezoelectric matrix component, polarization enhancement component, free radical activation and electron capture component and film-forming component were adjusted to 120 parts, 40 parts, 15 parts and 15 parts, respectively.

[0086] The selection of other components, component performance parameters, preparation process flow and process parameters are the same as in Example 1.

[0087] Example 4:

[0088] Based on Example 1, the weight percentage of bismuth ferrite (BiFeO3) nanoparticles in the polarization enhancement component was adjusted to 30 parts, the weight percentage of molybdenum disulfide (MoS2) sheets was adjusted to 10 parts, the weight percentage of iron oxide (Fe3O4) nanoparticles was adjusted to 45 parts, and the weight percentage of Ti3C2MXene sheet material remained unchanged at 10 parts.

[0089] The selection of other components, performance parameters, preparation process flow and process parameters are the same as in Example 1.

[0090] Example 5:

[0091] Based on Example 1, the weight percentage of nitrogen-doped graphene (N-Graphene) in the radical activation and electron capture component was adjusted to 40 parts, the weight percentage of graphitic carbon nitride (g-C3N4) was adjusted to 40 parts, and the weight percentage of molybdenum disulfide (MoS2) remained unchanged at 20 parts.

[0092] The selection of other components, performance parameters, preparation process flow and process parameters are the same as in Example 1.

[0093] Example 6:

[0094] Based on Example 1, dibutyl phthalate (DBP) was used to replace dioctyl phthalate (DOP) in the film-forming aid dispersion, while the proportions and performance parameters of other aids remained unchanged;

[0095] The selection of other components, performance parameters, preparation process flow and process parameters are the same as in Example 1.

[0096] Example 7:

[0097] Based on Example 1, the proportion of polyvinylpyrrolidone (PVP) in the flexible piezoelectric matrix component was adjusted to 5 parts, the proportion of fluorinated polyacrylate (FPAA) was adjusted to 5 parts, and the proportion of polyvinylidene fluoride (PVDF) was adjusted to 90 parts.

[0098] The selection of other components, performance parameters, preparation process flow and process parameters are the same as in Example 1.

[0099] Example 8:

[0100] Based on Example 1, the spin coating speed was adjusted to 3000 rpm and the spin coating time was adjusted to 30 seconds. The selection of other components, performance parameters and process parameters were the same as in Example 1.

[0101] Comparative Example 1:

[0102] Compared with Example 1, no polarization enhancement components were added, that is, no iron oxide (Fe3O4) nanoparticles, bismuth ferrite (BiFeO3) nanoparticles, molybdenum disulfide (MoS2) sheets and Ti3C2MXene sheet materials were added. The selection of other components, performance parameters and process parameters were the same as those in Example 1.

[0103] Comparative Example 2:

[0104] Compared with Example 1, no free radical activating and electron capturing components were added, that is, no graphitic carbon nitride (g-C3N4), nitrogen-doped graphene (N-Graphene) and molybdenum disulfide (MoS2) were added. The selection of other components, performance parameters and process parameters were the same as those in Example 1.

[0105] Comparative Example 3:

[0106] Compared with Example 1, no polarization treatment is performed, i.e., polarization step S7 is omitted, and the selection of other components, performance parameters and process parameters are the same as in Example 1.

[0107] Table 1: Performance Test Results of Piezoelectric Catalytic Materials

[0108] Sample number <![CDATA[Piezoelectric coefficient D 33 (pC / N)]]> Tetracycline degradation rate (%) Free radical signal intensity (au) Example 1 42.5 92.3 285 Example 2 39.8 88.1 260 Example 3 45.2 94.7 300 Example 4 41.7 91.2 278 Example 5 43.3 93 290 Example 6 42 91.5 282 Example 7 40.5 89.7 270 Example 8 44 93.5 295 Comparative Example 1 25.2 65.8 190 Comparative Example 2 28.5 68.4 200 Comparative Example 3 30.1 71.2 210

[0109] Table 2: Effect of Mixture Ratio Change on Piezoelectric Response

[0110] Sample number Number of flexible matrix components (parts) Number of polarization-enhancing components (parts) <![CDATA[Piezoelectric coefficient D 33 (pC / N)]]> Example 2 80 20 39.8 Example 1 100 30 42.5 Example 3 120 40 45.2 Comparative Example 1 100 0 25.2 Comparative Example 3 100 30 30.1

[0111] Table 3: Correlation between free radical enhancement and catalytic activity

[0112]

[0113]

[0114] Table 4: Relationship between polarization treatment and material properties

[0115] Sample number Polarization treatment <![CDATA[Piezoelectric coefficient D 33 (pC / N)]]> Tetracycline degradation rate (%) Example 1 yes 42.5 92.3 Example 3 yes 45.2 94.7 Example 8 yes 44 93.5 Comparative Example 3 no 30.1 71.2

[0116] Table 5: Test Results of Catalytic Reaction Characteristics of Piezoelectric Catalytic Materials

[0117] Sample number <![CDATA[Degradation reaction rate constant k (min -1 )]]> Surface roughness Ra (nm) Membrane adhesion (N / m) Example 1 0.043 88 18.5 Example 2 0.039 92 17.8 Example 3 0.047 85 19.1 Example 4 0.042 89 18.2 Example 5 0.045 86 18.7 Example 6 0.043 87 18.4 Example 7 0.04 91 17.9 Example 8 0.046 86 18.8 Comparative Example 1 0.021 105 14.5 Comparative Example 2 0.024 102 14.9 Comparative Example 3 0.027 100 15.2

[0118] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A piezoelectric catalytic material, characterized in that: A composite system comprising the following components in parts by weight: The flexible piezoelectric matrix component, in parts by weight of 80-120, is used to construct a flexible framework and provide a basic piezoelectric response. The polarization enhancement component, in parts by weight of 20-40, is used to enhance the interfacial polarization effect and improve carrier migration efficiency. The radical activating and electron capturing component, in parts by weight of 5-15, is used to promote the generation of free radicals and optimize electron capturing channels. The film-forming component, in parts by weight of 5-15, is used to optimize the film-forming properties and environmental stability of the composite material. The flexible piezoelectric matrix component is prepared in the following weight ratios: Polyvinylidene fluoride (PVDF), 95 parts, wherein the crystallinity of the β phase is not less than 70%, the molecular weight is in the range of 400,000–600,000 g / mol, and the melting point is in the range of 160–170°C; Polyvinylpyrrolidone (PVP), 3 parts, with a molecular weight of 40,000–60,000 g / mol, is used to enhance the orientation of polarized segments. Fluorinated polyacrylate FPAA, 2 parts, with an average particle size of less than 100 nm, is used to optimize tensile strength. The polarization-enhancing component is prepared in the following weight ratios: 50 parts of Fe3O4 nanoparticles with a particle size controlled between 50 and 80 nm and a magnetic saturation strength of not less than 60 emu / g; Bismuth ferrite BiFeO3 nanoparticles, 25 parts, monoclinic crystal form, with a particle size of 40–60 nm, exhibit anti-ferroelectric properties and a dielectric constant relative to the dielectric constant of over 300. Molybdenum disulfide (MoS2) sheets, 15 parts, with a layer thickness of less than 10 nm, a lateral dimension of more than 500 nm, and an electrical conductivity of more than 500 S / cm; Ten parts of Ti3C2MXene sheet material, with a thickness of 2–5 nm, an interlayer spacing of not less than 1 nm, and a specific surface area greater than 100 m². 2 / g; Aminosilane KH-550 surface modifier, added at 3% of the total weight of inorganic components, is used to improve the uniformity of filler dispersion and interfacial bonding strength in the polymer matrix. The radical activating and electron capturing component is prepared in the following weight ratios: Graphitic carbon nitride g-C3N4, 50 parts, with a sheet thickness of 5–10 nm and a specific surface area greater than 60 m². 2 / g, C / N molar ratio controlled at 0.65–0.7; Nitrogen-doped graphene (N-Graphene), 30 parts, with nitrogen doping concentration of 5–8 at%, sheet thickness less than 5 nm, and surface charge mobility greater than 1000 cm⁻¹. 2 / V·s; Molybdenum disulfide (MoS2), 20 parts, crystallinity greater than 90%, electron migration rate greater than 200 cm⁻¹ 2 / V·s, and has van der Waals heterojunction structure characteristics; The film-forming component is prepared in the following weight ratio: Aqueous polyurethane (PU) dispersion, 70 parts, solid content controlled at 30±2wt%, particle size less than 80nm; Irganox 1010 antioxidant, 20 parts, thermal decomposition temperature above 350°C, with free radical scavenging capacity greater than 90%; Dioctyl phthalate (DOP), 10 parts, with a molecular weight in the range of 390–410 g / mol and a boiling point above 380°C, is used to regulate the interaction forces between chain segments within the material and adjust the Young's modulus to the range of 100–300 MPa.

2. A method for preparing a piezoelectric catalytic material, comprising applying the piezoelectric catalytic material according to claim 1, characterized in that: S1: Preparation of flexible piezoelectric matrix precursor solution: Polyvinylidene fluoride (PVDF), polyvinylpyrrolidone (PVP), and fluorinated polyacrylate (FPAA) were mixed in a weight ratio of 95:3:2 and added to N,N-dimethylformamide (DMF) to control the mass fraction of the solution at 10–15%. The solution was then magnetically stirred at room temperature for 360 minutes until no visible precipitate was observed, thus obtaining the precursor solution. S2: Preparation of polarization-enhanced composite component dispersion: Fe3O4 nanoparticles, BiFeO3 nanoparticles, MoS2 sheets, and Ti3C2MXene sheets were mixed in a weight ratio of 50:25:15:10, added to anhydrous ethanol, and 3% (by weight) of aminosilane KH-550 surface modifier was added. The mixture was then ultrasonically treated for 1800 seconds to complete the dispersion. S3: Preparation of dispersion of free radical activation and electron capture composite components: Graphitic carbon nitride g-C3N4, nitrogen-doped graphene N-Graphene, and molybdenum disulfide MoS2 were mixed in a weight ratio of 50:30:20, added to isopropanol, and ultrasonically treated for 3600 seconds to complete dispersion. S4: Preparation of film-forming aid dispersion: A water-based polyurethane (PU) dispersion, Irganox 1010 antioxidant, and dioctyl phthalate (DOP) were mixed in a weight ratio of 70:20:10, and then added to a water-alcohol mixed solvent. The mixture was mechanically stirred for 240 minutes to prepare a film-forming aid dispersion. S5: Preparation of composite piezoelectric catalytic slurry: The flexible piezoelectric matrix precursor solution, polarization-enhanced composite component dispersion, free radical activation and electron capture composite dispersion, and film-forming aid dispersion are mixed according to a preset weight ratio, added to a high-speed disperser, and stirred at 500 rpm for 300 minutes. After completion, the mixture is placed under vacuum conditions with a pressure not exceeding -0.1 MPa for 60 minutes to degas and obtain the composite slurry.

3. The method for preparing a piezoelectric catalytic material according to claim 2, characterized in that: Also includes: S6: Film Forming and Drying: The composite piezoelectric catalytic slurry was coated onto the surface of the pretreated substrate using a spin coating method. The spin coating speed was set to 1000–3000 rpm and the spin coating time was set to 30–60 seconds. After spin coating, the sample was placed in a vacuum oven and dried at 80°C for 120 minutes. Then, the temperature was raised to 120°C and dried for another 480 minutes to prepare a dry piezoelectric catalytic film.

4. The method for preparing a piezoelectric catalytic material according to claim 3, characterized in that: Also includes: S7: Polarization treatment: The dried piezoelectric catalytic film was placed in a high-voltage polarization device, a DC electric field of 5–10 kV / cm was applied, the polarization temperature was controlled at 80–100°C, and the polarization time was set to 1800 seconds to complete the polarization treatment. S8: Membrane peeling and collection: The polarized piezoelectric catalytic membrane is peeled off from the substrate surface, cooled to room temperature, and cut to the required size to obtain the finished piezoelectric catalytic membrane.

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