Preparation method and application of two-dimensional nano barium titanate piezoelectric material

Abstract

The invention relates to the field of biomedical materials and oral care application, and particularly discloses a preparation method and application of a two-dimensional nano barium titanate piezoelectric material, and the method comprises the following steps: S1, mixing sodium chloride and potassium chloride, and grinding in a mortar; s2, adding bismuth oxide and titanium dioxide into the mortar in the step S1, mixing, and grinding; s3, calcining the mixture ground in the step S2, and cleaning and drying the calcined mixture to obtain a Bi4T i3O12 nano material; s4, preparing a sodium hydroxide solution, pouring the sodium hydroxide solution into the inner container of the reaction kettle, adding sodium oleate, and uniformly stirring; and S5, adding barium chloride and Bi4T i3O12 into the solution in the step S4, stirring, putting into a drying oven for reaction after stirring is completed, and washing and drying after the reaction is completed, thereby successfully preparing the two-dimensional nano barium titanate piezoelectric material. The method has relatively high biological safety and can realize high-efficiency degradation and antibacterial performance of the dye under the ultrasonic action, so that the method has relatively good application prospects in the aspects of tooth whitening and oral health protection.

Description

Technical Field

[0001] The present invention relates to the application fields of biomedical materials and oral care, and in particular to a preparation method and application of a two-dimensional nano-barium titanate piezoelectric material. Background Art

[0002] With the improvement of living standards, people are not only pursuing clean teeth, but also wanting to have white teeth. This has led to tooth whitening becoming one of the most popular cosmetic dental surgeries. However, in daily life, there are many factors that can cause tooth discoloration and staining. In addition to drugs, tobacco, colored food and beverages are also the triggering factors. At the same time, contaminated teeth provide a fertile and non-detachable environment for microorganisms colonizing in the mouth. Microorganisms from the mouth have been shown to cause a variety of oral diseases, including caries, periodontitis, etc. Therefore, designing and developing an oral medical material with high biosafety and efficient tooth whitening and antibacterial properties is of great significance for people to prevent oral diseases.

[0003] Piezoelectric materials have shown good application prospects in the medical field due to their good biocompatibility and piezoelectric catalytic properties, especially in the oral field (Nature Communications, 2020, 11: 1328). The Chinese patent (CN115634159B) "An antibacterial toothpaste" uses a charged antibacterial toothpaste abrasive including barium titanate (BaTiO3) particles. However, in order to make the barium titanate particles have the ability to whiten teeth and resist bacteria, corona polarization treatment is required. The main purpose of the polarization treatment step is to increase the catalytic and piezoelectric properties, which will undoubtedly limit the practical application of barium titanate materials and increase additional production costs. And the polarization ability may also weaken or even disappear over time after the polarization treatment. In addition, the piezoelectric properties of barium titanate particles are also weaker than those of barium titanate nanomaterials of other morphologies. For example, the piezoelectric properties of nanowires are higher than those of nanoparticles (ACS Applied Nano Materials, 2018, 1 (9): 5119-5127), thereby reducing the antibacterial and whitening abilities. Therefore, the development of barium titanate nanomaterials that are simple to synthesize, do not require polarization treatment, and have efficient piezoelectric properties is of great significance for the practical application of barium titanate in protecting oral health and teeth whitening. Summary of the invention

[0004] In order to overcome the defects and problems of the above-mentioned prior art, the present invention provides a method for preparing a two-dimensional nano-barium titanate piezoelectric material with high biological safety and good piezoelectric catalytic performance. The present invention first synthesizes bismuth titanate (Bi4Ti3O 12) material, and on this basis, a two-dimensional nano barium titanate (BaTiO3) piezoelectric material was prepared by a hydrothermal method. This technology combining grinding, calcination and hydrothermal method is relatively simple and easy to operate, and is convenient for large-scale preparation. In addition, through nano-sizing and two-dimensional structure design, the obtained two-dimensional nano BaTiO3 piezoelectric material has strong piezoelectric catalytic performance, can effectively inhibit the growth of Escherichia coli, and quickly degrade rhodamine B. Therefore, it can play an important role in teeth whitening and protecting oral health. In particular, it has good biosafety, which is of great significance for the clinical application of two-dimensional nano BaTiO3 piezoelectric materials.

[0005] The present invention adopts the following technical solution:

[0006] A method for preparing a two-dimensional nano-barium titanate piezoelectric material comprises the following steps:

[0007] S1. Weigh 1-10 g of sodium chloride (NaCl) and 1-10 g of potassium chloride (KCl), mix and grind in a mortar for 20-60 minutes;

[0008] S2, weigh 1-10g of bismuth oxide (Bi2O3) and 0.1-1g of titanium dioxide (TiO2), add them into the mortar in step S1, mix and grind for 1-5 hours;

[0009] S3, calcining the mixture ground in step S2 in a tube furnace for 1-5 hours, the calcination temperature is 500-800°C, the heating rate is 5-10°C / min, washing with water and ethanol for several times after calcination, and drying in an oven at 50-80°C to obtain Bi4Ti3O 12 Nanomaterials;

[0010] S4, prepare 10-15M sodium hydroxide (NaOH) solution, measure 50-100mL of NaOH solution and pour it into the 100-200mL reactor liner, then weigh 0.01-0.1g sodium oleate (C 18 H 33 NaO2) is added and stirred for 30-60 minutes;

[0011] S5, weigh 0.1-1.2g of barium chloride (BaCl2) and 0.1-0.4g of Bi4Ti3O prepared in step S3 12 Add it to the solution in step S4 and stir for 1-3 hours. After stirring, put it in an oven at 150-280°C to react for 10-20 hours. After the reaction, wash it with dilute nitric acid and ethanol several times, and dry it in an oven at 50-100°C to successfully prepare a two-dimensional nano barium titanate (BaTiO3) piezoelectric material.

[0012] Preferably, in step S1, 3-4 g of sodium chloride and 4-5 g of potassium chloride are weighed, mixed and ground in a mortar for 10-30 minutes.

[0013] Preferably, in step S2, 2-3 g of bismuth oxide and 0.5-1 g of titanium dioxide are weighed, added to the mortar in step S1, mixed, and ground for 2-4 hours.

[0014] Preferably, in step S2, 2.33 g of bismuth oxide and 0.6 g of titanium dioxide are weighed, added to the mortar in step S1, mixed, and ground for 2-4 hours.

[0015] Preferably, in step S3, the mixture ground in step S2 is calcined in a tube furnace for 1-3 hours at a calcination temperature of 600-800°C and a heating rate of 5-10°C / min. After calcination, it is washed with water and ethanol for multiple times and dried in an oven at 60-80°C to obtain Bi4Ti3O 12 Nanomaterials.

[0016] Preferably, in step S4, a 10-13M sodium hydroxide solution is prepared, 60-70 mL of the NaOH solution is measured and poured into a 100-150 mL reactor liner, and then 0.04-0.06 g of sodium oleate is weighed and added thereto, and stirred for 30-60 minutes.

[0017] Preferably, in step S4, a 12M sodium hydroxide solution is prepared, 65 mL of the NaOH solution is measured and poured into a 100 mL reactor liner, and then 0.05 g of sodium oleate is weighed and added thereto, and stirred for 30 minutes.

[0018] Preferably, in step S5, 0.8-1.2 g of barium chloride and 0.1-0.2 g of Bi4Ti3O prepared in step S3 are weighed. 12 Add it to the solution in step S4 and stir for 1-3 hours. After stirring, put it in an oven at 220-260°C to react for 15-18 hours. After the reaction, wash it with dilute nitric acid and ethanol several times, and dry it in an oven at 80-100°C to successfully prepare a two-dimensional nano barium titanate piezoelectric material.

[0019] Preferably, in step S5, 0.9 g of barium chloride and 0.17 g of Bi4Ti3O prepared in step S3 are weighed. 12 Add it to the solution in step S4 and stir for 1-3 hours. After stirring, put it in an oven at 220-260°C to react for 15-18 hours. After the reaction, wash it with dilute nitric acid and ethanol several times, and dry it in an oven at 80-100°C to successfully prepare a two-dimensional nano barium titanate piezoelectric material.

[0020] Another object of the present invention is to provide a two-dimensional nano-barium titanate piezoelectric material prepared by the preparation method of the two-dimensional nano-barium titanate piezoelectric material as described above, and use the two-dimensional nano-barium titanate piezoelectric material in oral antibacterial and tooth whitening.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention develops a method for preparing a two-dimensional nano-barium titanate piezoelectric material with high biological safety and good piezoelectric catalytic performance. The method uses a technology combining grinding calcination and hydrothermal method, which is simple to operate and suitable for large-scale preparation.

[0023] (2) Through nano-scaling and two-dimensional structure design, the prepared two-dimensional nano-barium titanate nanomaterials can have efficient piezoelectric catalytic performance without the need for polarization treatment.

[0024] (3) The prepared two-dimensional barium titanate nanomaterials have high biosafety and can achieve efficient degradation of dyes and antibacterial properties under ultrasound, thus having good application prospects in teeth whitening and protecting oral health. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a technical roadmap for the synthesis of two-dimensional nano-barium titanate (BaTiO3) piezoelectric materials.

[0026] Figure 2 Bi4Ti3O 12 (a) and XRD patterns of two-dimensional nano-BaTiO3 piezoelectric materials (b).

[0027] Figure 3 These are high-resolution transmission electron microscope images and lattice fringe images of two-dimensional nano BaTiO3 piezoelectric materials.

[0028] Figure 4 It is the mapping energy spectrum of two-dimensional nano-BaTiO3 piezoelectric material.

[0029] Figure 5 This is the XPS analysis chart of two-dimensional nano BaTiO3 piezoelectric material.

[0030] Figure 6 It is the piezoelectric performance spectrum of two-dimensional nano BaTiO3 piezoelectric material.

[0031] Figure 7 The MTT method is used to measure the effect of different concentrations of two-dimensional nano-BaTiO3 piezoelectric materials on cell activity (biosafety).

[0032] Figure 8 It is the antibacterial effect of two-dimensional nano BaTiO3 piezoelectric material under ultrasonic (US) and non-ultrasonic conditions.

[0033] Fig. 9 It is the dye degradation performance of two-dimensional nano BaTiO3 piezoelectric material.

[0034] Fig.10 These are images of bovine teeth in pure deionized water and a solution containing two-dimensional nano-BaTiO3 piezoelectric material before and after ultrasound treatment for 3 hours. DETAILED DESCRIPTION

[0035] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example 1: Synthesis of two-dimensional nano-barium titanate (BaTiO3) piezoelectric material

[0037] (1) Weigh 3.625 g of NaCl and 4.659 g of KCl, mix and grind in a mortar for 20 minutes.

[0038] (2) Weigh 2.33 g of Bi2O3 and 0.6 g of TiO2, add them to the mortar in step 1, mix and grind for 3 hours.

[0039] (3) The ground mixture in step 2 was calcined in a tube furnace for 2 hours at a calcination temperature of 700°C and a heating rate of 5°C / min. After calcination, it was washed with water and ethanol several times and dried in an oven at 70°C to obtain Bi4Ti3O 12 Material.

[0040] (4) Prepare 12M NaOH solution, measure 60mL of NaOH solution and pour it into the 100mL reactor liner, then weigh 0.05g of C 18 H 33 Add NaO2 and stir for 30 minutes.

[0041] (5) After the stirring is completed, weigh 0.9 g of BaCl2 and 0.17 g of Bi4Ti3O 12 Add it to the above solution and stir for 1.5 hours. After stirring, put it in an oven at 240°C to react for 16 hours. After the reaction, wash it with dilute nitric acid and ethanol several times, and dry it in an oven at 80°C to successfully prepare a two-dimensional nano BaTiO3 piezoelectric material.

[0042] like Figure 1As shown in the figure, the synthesis technology roadmap of two-dimensional nano-barium titanate (BaTiO3) piezoelectric materials is mainly divided into two parts: grinding and calcining and hydrothermal synthesis. The grinding and calcining part: Steps 1-3 are grinding and calcining to prepare Bi4Ti3O 12 Materials. Figure 2 (a) shows the Bi4Ti3O prepared in step 3 12 The XRD spectrum of the material shows sharp diffraction peaks with high peak intensity, indicating that Bi4Ti3O 12 The material has good crystallization performance and high purity. Hydrothermal synthesis part: Steps 4-5 are hydrothermal synthesis to prepare two-dimensional nano BaTiO3 piezoelectric materials. Figure 2 (b) shows the XRD spectrum of the two-dimensional nano-BaT iO3 piezoelectric material prepared in step 5. An obvious characteristic peak (110) belonging to the BaT iO3 piezoelectric material appears, and there are no extra impurity peaks. This indicates that the synthesized material is completely composed of two-dimensional nano-BaT iO3 piezoelectric material with high purity and no impurities.

[0043] Example 2: Synthesis and characterization of two-dimensional nano-barium titanate (BaTiO3) piezoelectric materials

[0044] The synthesized BaTiO3 piezoelectric material was characterized to further study its morphological and structural characteristics. Figure 3 ) It can be seen that the synthesized BaT iO3 nanomaterial is a two-dimensional sheet structure with an average size of about 150nm, which shows that the two-step method can be used to achieve nano-sizing and two-dimensional structural design of BaT iO3 nanomaterials, thereby preparing two-dimensional nano-barium titanate (BaT iO3) piezoelectric materials. At the same time, the lattice fringes and diffraction images once again prove that the obtained two-dimensional nano-BaT iO3 piezoelectric material belongs to the pure BaT iO3 phase ( Figure 3 ), which is consistent with the XRD results, indicating that the synthesis is of high purity and no impurities are generated. Finally, the two-dimensional nano BaTiO3 piezoelectric material was mapped by energy spectrum analysis ( Figure 4 ), it can be found that the two-dimensional nano BaTiO3 piezoelectric material is composed of only three elements: Ba, Ti, and O, with a distribution ratio of 59.92%, 19.94%, and 20.14% respectively. This also proves again that the two-dimensional nano BaTiO3 piezoelectric material prepared by the two-step method has a high purity and no impurities are doped into it. In order to further verify the structure and purity of the two-dimensional nano BaTiO3 piezoelectric material, the two-dimensional nano BaTiO3 piezoelectric material was tested by X-ray photoelectron spectroscopy (XPS). Figure 5 As shown, Figure 5 This is the XPS analysis diagram of two-dimensional nano BaTiO3 piezoelectric material. Figure 5(a) is the XPS total spectrum, (b) is the high-resolution spectrum of Ba 3d, (c) is the high-resolution spectrum of O1s, and (d) is the high-resolution spectrum of Ti2p. The characteristic peaks of Ba 3d, O 1s, and Ti2p can be clearly seen, indicating that BaTiO3 is composed of these elements and maintains normal valence elements. There are no other impurity elements that affect the distribution of characteristic peaks.

[0045] Based on the analysis of Examples 1 and 2, the nano-sizing and two-dimensional structure design of BaT iO 3 nanomaterials can be achieved by combining a simple grinding, calcination and hydrothermal two-step method, and high-purity two-dimensional nano BaT iO 3 piezoelectric materials can be successfully prepared.

[0046] Example 3: Piezoelectric performance test of two-dimensional nano BaTiO3 piezoelectric material

[0047] The piezoelectric properties of two-dimensional nano-BaTiO3 piezoelectric materials are of great significance for the application of two-dimensional nano-BaTiO3 piezoelectric materials. For this reason, the prepared two-dimensional nano-BaTiO3 piezoelectric materials were tested by piezoelectric response force microscopy and piezoelectric hysteresis loop. The experimental results are as follows Figure 6 As shown, Figure 6 The piezoelectric performance spectrum of two-dimensional nano BaTiO3 piezoelectric material: Figure 6 (a) is the out-of-plane PFM amplitude image, (b) PFM phase image, (cf) the amplitude butterfly loop and phase lag loop when the AC voltage is: -12V~12V, (d) -6V~6V, (e) -8V~8V, (f) -10V~10V;

[0048] (j) In-plane PFM amplitude image, (h) PFM phase image, (i) Amplitude butterfly loop and phase hysteresis loop under -10V to 10V AC voltage; (a) and (b) are out-of-plane phase images of two-dimensional nano-BaTiO3 piezoelectric materials. It can be observed that the area is obviously different from the substrate, indicating that the two-dimensional nano-BaTiO3 piezoelectric material has a certain ferroelectric polarization, and the polarization direction is obviously different from the substrate, while the in-plane phase images 6 (j) and 6 (h) are not obviously different, which once again proves that the two-dimensional nano-BaTiO3 piezoelectric material has good piezoelectric properties. In addition, Figure 6 (cf) It can be found that the two-dimensional nano BaTiO3 piezoelectric material produces amplitude under different voltage stimulation, and a phase angle reversal of ~180° occurs. Through the amplitude curve of the two-dimensional nano BaTiO3 piezoelectric material, it is found that the two-dimensional nano BaTiO3 piezoelectric material shows a more obvious amplitude response, while the amplitude within the plane has no response ( Figure 6(i)), which shows that the two-dimensional nano BaTiO3 piezoelectric material has a good response to voltage, that is, it has good piezoelectric properties and good piezoelectric catalytic ability.

[0049] Example 4: Biological safety of two-dimensional nano BaTiO3 piezoelectric materials

[0050] The biosafety of two-dimensional nano BaTiO3 piezoelectric materials is of great significance for their use in teeth whitening and oral protection. Only non-toxic properties can be applied in real life. Here, the standard MTT method was used to evaluate the effect of two-dimensional nano BaTiO3 piezoelectric materials on cell activity in vitro. Figure 7 The cell survival rate of L-929 cells after being treated with two-dimensional nano-BaT iO3 piezoelectric materials at different concentrations. It can be seen that the two-dimensional nano-BaT iO3 piezoelectric material has almost no cytotoxicity and has high biosafety.

[0051] Example 5: Antibacterial effect of two-dimensional nano BaTiO3 piezoelectric material

[0052] The antibacterial effect of two-dimensional nano BaTiO3 piezoelectric materials on Escherichia coli under different conditions was studied using the colony plating method. Figure 8 As shown, the results show that the two-dimensional nano BaT iO3 piezoelectric material has almost no antibacterial effect under the condition of no ultrasound (US). Under US conditions, the number of colonies on the plate of the two-dimensional nano BaT iO3 piezoelectric material group was significantly less than that of the control group, indicating that the two-dimensional nano BaT iO3 piezoelectric material has a significant antibacterial effect under US, which indicates that the two-dimensional nano BaT iO3 piezoelectric material can be used in oral antibacterial and has a certain effect in protecting oral health.

[0053] Example 6: Teeth whitening effect of two-dimensional nano BaTiO3 piezoelectric material

[0054] The experiments were conducted using Rhodamine B (RhB) dye to simulate tooth staining substances. Fig. 9 Dye degradation performance of two-dimensional nano BaTiO3 piezoelectric materials, Fig. 9 (a) is the degradation absorption value without BaT iO3 at different times; (b) is the degradation absorption value with BaT iO3 at different times; (c) is the degradation curve of RhB; (US: ultrasound, BTO: two-dimensional nano BaT iO3 piezoelectric material), such as Fig. 9 As shown in (a), when no two-dimensional nano BaTiO3 piezoelectric material is added, RhB does not undergo obvious degradation and the absorption value does not decrease substantially, which indicates that US alone cannot degrade the dye. Fig. 9As shown in (b), when two-dimensional nano-BaTiO3 piezoelectric material is added to the RhB solution, the absorption value is significantly reduced, and RhB is rapidly degraded within 4 minutes, which proves that two-dimensional nano-BaTiO3 piezoelectric material can achieve efficient degradation of RhB ( Fig. 9 (c)).

[0055] The degradation experiment of RhB proved that the two-dimensional nano BaTiO3 piezoelectric material has good piezoelectric catalytic ability, can achieve efficient degradation of dyes, and can be used for tooth whitening. In order to further improve the tooth whitening effect, purchased cow teeth were used to simulate human teeth for tooth whitening experiments. The ex vivo teeth were soaked in RhB dye for 48 hours and then washed with deionized water to remove the residual dye. Photos of teeth treated with deionized water and two-dimensional nano BaTiO3 piezoelectric materials with and without ultrasound (US) were taken ( Fig.10 ). The stained teeth treated with ultrasound in a solution containing two-dimensional nano BaTiO3 piezoelectric material turned white, while the stained teeth in deionized water showed an imperceptible color change under the same vibration conditions. This shows that two-dimensional nano BaTiO3 piezoelectric material can be fully applied to the removal of stains on the tooth surface and has a tooth whitening effect.

[0056] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0057] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing a two-dimensional nano-barium titanate piezoelectric material, characterized in that: The following steps are involved: S1. Weigh 1-10 g of sodium chloride and 1-10 g of potassium chloride, mix and grind in a mortar for 20-60 minutes; S2, weighing 1-10g of bismuth oxide and 0.1-1g of titanium dioxide, adding them into the mortar in step S1, mixing and grinding for 1-5 hours; S3, calcining the mixture ground in step S2 in a tube furnace for 1-5 hours, the calcination temperature is 500-800°C, the heating rate is 5-10°C / min, washing with water and ethanol for several times after calcination, and drying in an oven at 50-80°C to obtain Bi4Ti3O 12 Nanomaterials; S4, prepare 10-15M sodium hydroxide solution, measure 50-100mL of NaOH solution and pour it into the 100-200mL reactor liner, then weigh 0.01-0.1g sodium oleate and add it, stirring for 30-60 minutes; S5, weigh 0.1-1.2g of barium chloride and 0.1-0.4g of Bi4Ti3O prepared in step S3. 12 Add it to the solution in step S4 and stir for 1-3 hours. After stirring, put it in an oven at 150-280°C to react for 10-20 hours. After the reaction, wash it with dilute nitric acid and ethanol several times, and dry it in an oven at 50-100°C to successfully prepare a two-dimensional nano barium titanate piezoelectric material.

2. The method for preparing a two-dimensional nano-barium titanate piezoelectric material according to claim 1, characterized in that: In step S1, 3-4 g of sodium chloride and 4-5 g of potassium chloride are weighed, mixed and ground in a mortar for 10-30 minutes.

3. The method for preparing a two-dimensional nano-barium titanate piezoelectric material according to claim 1, characterized in that: In step S2, 2-3 g of bismuth oxide and 0.5-1 g of titanium dioxide are weighed and added into the mortar in step S1, mixed and ground for 2-4 hours.

4. The method for preparing a two-dimensional nano-barium titanate piezoelectric material according to claim 3, characterized in that: In step S2, 2.33 g of bismuth oxide and 0.6 g of titanium dioxide are weighed and added into the mortar in step S1, mixed and ground for 2-4 hours.

5. The method for preparing a two-dimensional nano-barium titanate piezoelectric material according to claim 1, characterized in that: In step S3, the mixture ground in step S2 is calcined in a tube furnace for 1-3 hours at a calcination temperature of 600-800°C and a heating rate of 5-10°C / min. After calcination, it is washed with water and ethanol for multiple times and dried in an oven at 60-80°C to obtain Bi4Ti3O 12 Nanomaterials.

6. The method for preparing a two-dimensional nano-barium titanate piezoelectric material according to claim 1, characterized in that: In step S4, a 10-13M sodium hydroxide solution is prepared, 60-70 mL of the NaOH solution is measured and poured into a 100-150 mL reactor liner, and then 0.04-0.06 g of sodium oleate is weighed and added thereto, and stirred for 30-60 minutes.

7. The method for preparing a two-dimensional nano-barium titanate piezoelectric material according to claim 6, characterized in that: In step S4, a 12M sodium hydroxide solution was prepared, 65 mL of the NaOH solution was measured and poured into a 100 mL reactor liner, and then 0.05 g of sodium oleate was weighed and added thereto, and stirred for 30 minutes.

8. The method for preparing a two-dimensional nano-barium titanate piezoelectric material according to claim 1, characterized in that: In step S5, weigh 0.8-1.2 g of barium chloride and 0.1-0.2 g of Bi4Ti3O prepared in step S3. 12 Add it to the solution in step S4 and stir for 1-3 hours. After stirring, put it in an oven at 220-260°C to react for 15-18 hours. After the reaction, wash it with dilute nitric acid and ethanol several times, and dry it in an oven at 80-100°C to successfully prepare a two-dimensional nano barium titanate piezoelectric material.

9. The method for preparing a two-dimensional nano-barium titanate piezoelectric material according to claim 8, characterized in that: In step S5, 0.9 g of barium chloride and 0.17 g of Bi4Ti3O prepared in step S3 were weighed. 12 Add it to the solution in step S4 and stir for 1-3 hours. After stirring, put it in an oven at 220-260°C to react for 15-18 hours. After the reaction, wash it with dilute nitric acid and ethanol several times, and dry it in an oven at 80-100°C to successfully prepare a two-dimensional nano barium titanate piezoelectric material.

10. Application of the two-dimensional nano-barium titanate piezoelectric material prepared by the method for preparing the two-dimensional nano-barium titanate piezoelectric material as claimed in claim 1 in oral antibacterial and tooth whitening.

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