Method for synchronously preparing flexible ceramic nanowire film and carbon nanotube by utilizing high-temperature cracking of polymer precursor

Abstract

The invention discloses a method for synchronously preparing a flexible ceramic nanowire film and a carbon nano tube by utilizing high-temperature cracking of a polymer precursor, and belongs to the technical field of one-dimensional nano materials. The method comprises the following steps: preparing a Si3N4 nanowire film; cutting the Si3N4 nanowire film into a plurality of sheets with the same size, sequentially arranging the precursor powder and the plurality of sheets in a tubular furnace along a gas flow direction, arranging the precursor powder at a central position between a gas inlet end and a tail gas end, arranging the plurality of sheets between the central position and the tail gas end, and then introducing nitrogen gas, and carrying out second high-temperature heat treatment to generate the Si3N4 nanowire film from the precursor powder, and growing the carbon nanotubes in situ on the surface of the sheet by using the gas generated when the Si3N4 nanowire film is generated. According to the method, the carbon nanotubes are prepared from small molecule gas waste generated when the flexible Si3N4 nanowire thin film is prepared through high-temperature cracking of a polymer precursor, and waste gas generated through polymer cracking is recycled.

Description

Technical Field

[0001] This invention belongs to the field of one-dimensional nanomaterials technology, specifically relating to a method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors. Background Technology

[0002] One-dimensional nanomaterials refer to materials with radial (one or two dimensions) dimensions at the nanometer level, such as nanowires, nanorods, nanoribbons, and nanotubes. Among them, one-dimensional ceramic nanowires have attracted increasing attention due to their excellent thermal stability, corrosion resistance, and mechanical properties. Currently, various one-dimensional ceramic nanowires have been prepared using polymer precursors, such as SiC nanowires (Tian X., Yang L., Li B., et al. Ablation behaviors of SiC nanowire-reinforced ZrC-SiC coating-matrix integrated C / C composites with different ratios of precursors. Journal of the European Ceramic Society, 2022, 42(15): 6774-678), HfC nanowires (Fu Y., Zhang Y., Yin X., et al. Two birds with one stone: Simultaneous fabrication of HfC nanowires and CNTs through efficient utilization of polymer-derived ceramics. Journal of Materials Science & Technology, 2022, 129: 163-172.), and ZrC nanowires (K. Wang, K. Zhao, Q. Meng, et al. Preparation of zirconium carbide nanofibers by electrospinning of purezirconium-containing polymer). Ceramics International, 2022, 48(17): 25474-2548.) etc.

[0003] However, most currently prepared ceramic nanowires are distributed within or on the surface of the matrix, failing to form independent flexible bodies. Furthermore, during the conversion of ceramic nanowires, the polymer precursor continuously decomposes upon heating, generating large amounts of small molecules such as CO, CO2, and CH4, which are directly released into the air. This not only fails to effectively utilize the polymer precursor but also harms environmental protection. Therefore, while utilizing polymer precursors to prepare flexible, independent ceramic nanowire films, the recycling of waste gases generated by polymer decomposition is particularly important. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors. The method utilizes the flexible Si3N4 nanowire films prepared by high-temperature pyrolysis of polymer precursors, and utilizes the small molecule gas waste generated during the preparation of the flexible Si3N4 nanowire films by high-temperature pyrolysis of polymer precursors to prepare carbon nanotubes, thereby recycling the waste gas generated by polymer pyrolysis.

[0005] To achieve the above objectives, the present invention employs the following technical solution: This invention provides a method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors, comprising the following steps: S1: Polysilazane, ferrocene and xylene are mixed evenly to obtain solution A. Solution A is then air-dried and cured, and then ground to obtain powder B as a precursor powder. The precursor powder is subjected to a first high-temperature heat treatment under nitrogen to obtain Si3N4 nanowire thin film. S2: The Si3N4 nanowire film is cut into several thin sheets of the same size. The precursor powder and several thin sheets are sequentially placed in a tube furnace along the gas flow direction, with the precursor powder at the center position between the gas inlet and the gas outlet. The several thin sheets are placed between the center position and the gas outlet. Nitrogen gas is then introduced for a second high-temperature heat treatment. The precursor powder generates Si3N4 nanowire film. The gas generated during the generation of Si3N4 nanowire film grows carbon nanotubes in situ on the surface of the thin sheets.

[0006] In one embodiment, in step S1, the mass ratio of the polysilazane to ferrocene is (7-10):1; the volume ratio of the xylene to the polysilazane is (2-5):1; and the air-drying time is 5-8 days.

[0007] In one embodiment, in step S2, the flow rate of the introduced nitrogen gas is 60-100 sccm.

[0008] In one embodiment, the first high-temperature heat treatment and the second high-temperature heat treatment in S1 and S2 are as follows: the furnace temperature is raised to 1300~1500 ℃ at a heating rate of 5~10 ℃ / min, and the holding time is 2~3 h.

[0009] In one embodiment, the gas generated during the formation of the Si3N4 nanowire thin film in S2 includes CO2, CO, and CH4.

[0010] In one embodiment, in step S2, the plurality of thin sheets are arranged at equal intervals.

[0011] In one embodiment, in step S2, the precursor powder is in the temperature range of 1300~1500 °C of a tube furnace.

[0012] In one embodiment, the plurality of thin sheets are respectively located in the temperature range of 1200 ℃ to 800 ℃ of the tube furnace.

[0013] In one embodiment, the plurality of thin sheets are respectively located in the temperature ranges of 1200 °C, 1000 °C and 800 °C of the tube furnace.

[0014] In one embodiment, the carbon nanotubes on each Si3N4 nanowire in the Si3N4 nanowire film are intertwined and uniformly distributed.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes using high-temperature pyrolysis of polymer precursors. By employing an organic precursor, Si3N4, flexible Si3N4 nanowire films and carbon nanotubes are simultaneously prepared through high-temperature pyrolysis. This method not only produces independent flexible bodies like Si3N4 nanowire films but also grows carbon nanotubes on these films, enabling the recovery of waste gas generated during polymer synthesis and achieving efficient utilization of the polymer precursor. This method effectively reduces costs, protects the environment, and has broad applications in polymer-derived ceramics, showing promise for large-scale industrial production. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the preparation process of simultaneously preparing flexible ceramic nanowire films and carbon nanotubes according to the present invention.

[0017] Figure 2 Images (a), (b), and (c) are optical photographs and SEM images of the flexible Si3N4 nanowire thin films prepared in this invention.

[0018] Figure 3This is a SEM image of the carbon nanotubes prepared on Si3N4 nanowire thin films according to the present invention. Detailed Implementation

[0019] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0020] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0021] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0022] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0023] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0024] The purpose of this invention is to achieve efficient utilization of polymer precursors and the utilization of gases generated during the formation of Si3N4 nanowire films. Therefore, a method for simultaneously preparing flexible Si3N4 nanowire films and carbon nanotubes using high-temperature polymer pyrolysis is proposed, comprising the following steps: S1: Polysilazane, ferrocene and xylene are mixed evenly to obtain solution A. Solution A is then air-dried and cured, and then ground to obtain powder B as a precursor powder. The precursor powder is subjected to a first high-temperature heat treatment under nitrogen to obtain Si3N4 nanowire thin film. S2: The Si3N4 nanowire film is cut into several thin sheets of the same size. The precursor powder and several thin sheets are sequentially placed in a tube furnace along the gas flow direction, with the precursor powder at the center position between the gas inlet and the gas outlet. The several thin sheets are placed between the center position and the gas outlet. Nitrogen gas is then introduced for a second high-temperature heat treatment. The precursor powder generates Si3N4 nanowire film. The gas generated during the generation of Si3N4 nanowire film grows carbon nanotubes in situ on the surface of the thin sheets.

[0025] In one specific embodiment, the method includes the following steps: Step 1: Mix polysilazane, ferrocene and xylene evenly to obtain solution A, wherein the mass ratio of polysilazane to ferrocene is (7-10):1 and the volume ratio of xylene to polysilazane is (2-5):1. Step 2: Air dry solution A for 5-8 days to solidify, then grind it to obtain powder B; Step 3: Place the graphite paper coated with powder B in a heat treatment furnace, introduce N2, raise the furnace temperature to 1300~1500 ℃ at a heating rate of 5~10 ℃ / min, and hold for 2~3 h to obtain Si3N4 nanowire thin film, i.e. sample C; like Figure 1 As shown, step 4: simultaneous preparation of flexible ceramic nanowire films and carbon nanotubes: cut sample C into several thin sheets of the same size, and then place graphite paper with powder B spread on it and the cut thin sheets in a tube furnace at the same time. The graphite paper with powder B spread on it is placed within the set temperature range of the tube furnace, while the multiple thin sheets are placed at different temperature zones (1200 ℃, 1000 ℃ and 800 ℃) at the set temperature zone and the tail gas end of the furnace tube, namely S1, S2 and S3. Then, N2 at different flow rates (60~100 sccm) was introduced, and the furnace temperature was raised to 1300~1500 ℃ at a heating rate of 5~10 ℃ / min. The holding time was 2~3 h. After the holding time was completed, the heating power was turned off, and the furnace was cooled to obtain Si3N4 nanowire film D. At the same time, carbon nanotubes were grown in situ on the surface of the cut Si3N4 nanowire film C, realizing the simultaneous preparation of flexible Si3N4 nanowire film and carbon nanotubes.

[0026] The method for simultaneously preparing flexible Si3N4 nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors provided by this invention not only achieves efficient utilization of polymer precursors, but also recovers small molecule gases CO2, CO and CH4 generated during polymer pyrolysis, which has the advantages of reducing costs, protecting the environment and saving resources.

[0027] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0028] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0029] Example 1: Step 1: Mix polysilazane, ferrocene and xylene evenly to obtain solution A, wherein the mass ratio of polysilazane to ferrocene is 7:1 and the volume ratio of xylene to polysilazane is 2:1. Step 2: Air-dry solution A for 8 days to solidify, then grind it to obtain powder B; Step 3: Place the graphite paper coated with powder B in a heat treatment furnace, introduce N2, raise the furnace temperature to 1300~1500 ℃ at a heating rate of 5~10 ℃ / min, and hold for 2~3 h to obtain Si3N4 nanowire thin film sample C. Step 4: Cut sample C into thin sheets of the same size. Then, place graphite paper with powder B spread on it and the cut sheets simultaneously in a tube furnace. The graphite paper with powder B spread on it is placed within the set temperature range of the tube furnace, while multiple sheets are placed at different temperature zones (1200 ℃, 1000 ℃, and 800 ℃) at the set temperature zone and the tail gas end of the furnace tube, namely S1, S2, and S3. Then, N2 at different flow rates of 60 sccm is introduced, and the furnace temperature is raised to 1300 ℃ at a heating rate of 5 ℃ / min. The holding time is 2~3 h. After the holding time is completed, the heating power is turned off, and the furnace is cooled to obtain Si3N4 nanowire film D. At the same time, carbon nanotubes are grown in situ on the surface of the cut Si3N4 nanowire film C, realizing the simultaneous preparation of flexible Si3N4 nanowire film and carbon nanotubes.

[0030] Example 2: Step 1: Mix polysilazane, ferrocene and xylene evenly to obtain solution A, wherein the mass ratio of polysilazane to ferrocene is 9:1 and the volume ratio of xylene to polysilazane is 3:1. Step 2: Air-dry solution A for 5 days to solidify, then grind it to obtain powder B; Step 3: Place the graphite paper coated with powder B in a heat treatment furnace, introduce N2, raise the furnace temperature to 1300~1500 ℃ at a heating rate of 5~10 ℃ / min, and hold for 2~3 h to obtain Si3N4 nanowire thin film sample C. Step 4: Cut sample C into thin sheets of the same size. Then, place graphite paper with powder B spread on it and the cut sheets simultaneously in a tube furnace. The graphite paper with powder B spread on it is placed within the set temperature range of the tube furnace, while multiple sheets are placed at different temperature zones (1200 ℃, 1000 ℃, and 800 ℃) at the set temperature zone and the tail gas end of the furnace tube, namely S1, S2, and S3. Then, N2 at different flow rates of 80 sccm is introduced, and the furnace temperature is raised to 1400 ℃ at a heating rate of 7 ℃ / min. The holding time is 2~3 h. After the holding time is completed, the heating power is turned off, and the furnace is cooled to obtain Si3N4 nanowire film D. At the same time, carbon nanotubes are grown in situ on the surface of the cut Si3N4 nanowire film C, realizing the simultaneous preparation of flexible Si3N4 nanowire film and carbon nanotubes.

[0031] Example 3: Step 1: Mix polysilazane, ferrocene and xylene evenly to obtain solution A, wherein the mass ratio of polysilazane to ferrocene is 10:1 and the volume ratio of xylene to polysilazane is 5:1. Step 2: Air-dry solution A for 7 days to solidify, then grind it to obtain powder B; Step 3: Place the graphite paper coated with powder B in a heat treatment furnace, introduce N2, raise the furnace temperature to 1300~1500 ℃ at a heating rate of 5~10 ℃ / min, and hold for 2~3 h to obtain Si3N4 nanowire thin film sample C. Step 4: Cut sample C into thin sheets of the same size. Then, place graphite paper with powder B spread on it and the cut sheets simultaneously in a tube furnace. The graphite paper with powder B spread on it is placed within the set temperature range of the tube furnace, while multiple sheets are placed at different temperature zones (1200 ℃, 1000 ℃, and 800 ℃) at the set temperature zone and the tail gas end of the furnace tube, namely S1, S2, and S3. Then, N2 at different flow rates of 100 sccm is introduced, and the furnace temperature is raised to 1500 ℃ at a heating rate of 9 ℃ / min. The holding time is 2~3 h. After the holding time is completed, the heating power is turned off, and the furnace is cooled to obtain Si3N4 nanowire film D. At the same time, carbon nanotubes are grown in situ on the surface of the cut Si3N4 nanowire film C, realizing the simultaneous preparation of flexible Si3N4 nanowire film and carbon nanotubes.

[0032] Example 4: Step 1: Mix polysilazane, ferrocene and xylene evenly to obtain solution A, wherein the mass ratio of polysilazane to ferrocene is 7:1 and the volume ratio of xylene to polysilazane is 2:1. Step 2: Air-dry solution A for 8 days to solidify, then grind it to obtain powder B; Step 3: Place the graphite paper coated with powder B in a heat treatment furnace, introduce N2, raise the furnace temperature to 1300~1500 ℃ at a heating rate of 5~10 ℃ / min, and hold for 2~3 h to obtain Si3N4 nanowire thin film sample C. Step 4: Cut sample C into thin sheets of the same size. Then, place graphite paper with powder B spread on it and the cut sheets simultaneously in a tube furnace. The graphite paper with powder B spread on it is placed within the set temperature range of the tube furnace, while multiple sheets are placed at different temperature zones (1200 ℃, 1000 ℃, and 800 ℃) at the set temperature zone and the tail gas end of the furnace tube, namely S1, S2, and S3. Then, N2 at different flow rates of 60 sccm is introduced, and the furnace temperature is raised to 1500 ℃ at a heating rate of 10 ℃ / min. The holding time is 2~3 h. After the holding time is completed, the heating power is turned off, and the furnace is cooled to obtain Si3N4 nanowire film D. At the same time, carbon nanotubes are grown in situ on the surface of the cut Si3N4 nanowire film C, realizing the simultaneous preparation of flexible Si3N4 nanowire film and carbon nanotubes.

[0033] Example 5: Step 1: Mix polysilazane, ferrocene and xylene evenly to obtain solution A, wherein the mass ratio of polysilazane to ferrocene is 9:1 and the volume ratio of xylene to polysilazane is 3:1. Step 2: Air-dry solution A for 5 days to solidify, then grind it to obtain powder B; Step 3: Place the graphite paper coated with powder B in a heat treatment furnace, introduce N2, raise the furnace temperature to 1300~1500 ℃ at a heating rate of 5~10 ℃ / min, and hold for 2~3 h to obtain Si3N4 nanowire thin film sample C. Step 4: Cut sample C into thin sheets of the same size. Then, place graphite paper with powder B spread on it and the cut sheets simultaneously in a tube furnace. The graphite paper with powder B spread on it is placed within the set temperature range of the tube furnace, while multiple sheets are placed at different temperature zones (1200 ℃, 1000 ℃, and 800 ℃) at the set temperature zone and the tail gas end of the furnace tube, namely S1, S2, and S3. Then, N2 at different flow rates of 80 sccm is introduced, and the furnace temperature is raised to 1500 ℃ at a heating rate of 8 ℃ / min. The holding time is 2~3 h. After the holding time is completed, the heating power is turned off, and the furnace is cooled to obtain Si3N4 nanowire film D. At the same time, carbon nanotubes are grown in situ on the surface of the cut Si3N4 nanowire film C, realizing the simultaneous preparation of flexible Si3N4 nanowire film and carbon nanotubes.

[0034] Example 6: Step 1: Mix polysilazane, ferrocene and xylene evenly to obtain solution A, wherein the mass ratio of polysilazane to ferrocene is 10:1 and the volume ratio of xylene to polysilazane is 5:1. Step 2: Air-dry solution A for 7 days to solidify, then grind it to obtain powder B; Step 3: Place the graphite paper coated with powder B in a heat treatment furnace, introduce N2, raise the furnace temperature to 1300~1500 ℃ at a heating rate of 5~10 ℃ / min, and hold for 2~3 h to obtain Si3N4 nanowire thin film sample C. Step 4: Cut sample C into thin sheets of the same size. Then, place graphite paper with powder B spread on it and the cut sheets simultaneously in a tube furnace. The graphite paper with powder B spread on it is placed within the set temperature range of the tube furnace, while multiple sheets are placed at different temperature zones (1200 ℃, 1000 ℃, and 800 ℃) at the set temperature zone and the tail gas end of the furnace tube, namely S1, S2, and S3. Then, N2 at different flow rates of 100 sccm is introduced, and the furnace temperature is raised to 1500 ℃ at a heating rate of 5 ℃ / min. The holding time is 2~3 h. After the holding time is completed, the heating power is turned off, and the furnace is cooled to obtain Si3N4 nanowire film D. At the same time, carbon nanotubes are grown in situ on the surface of the cut Si3N4 nanowire film C, realizing the simultaneous preparation of flexible Si3N4 nanowire film and carbon nanotubes.

[0035] Example 7: Step 1: Mix polysilazane, ferrocene and xylene evenly to obtain solution A, wherein the mass ratio of polysilazane to ferrocene is 10:1 and the volume ratio of xylene to polysilazane is 5:1. Step 2: Air-dry solution A for 7 days to solidify, then grind it to obtain powder B; Step 3: Place the graphite paper coated with powder B in a heat treatment furnace, introduce N2, raise the furnace temperature to 1300~1500 ℃ at a heating rate of 5~10 ℃ / min, and hold for 2~3 h to obtain Si3N4 nanowire thin film sample C. Step 4: Cut sample C into thin sheets of the same size. Then, place graphite paper with powder B spread on it and the cut sheets simultaneously in a tube furnace. The graphite paper with powder B spread on it is placed within the set temperature range of the tube furnace, while multiple sheets are placed at different temperature zones (1200 ℃, 1000 ℃, and 800 ℃) at the set temperature zone and the tail gas end of the furnace tube, namely S1, S2, and S3. Then, N2 at different flow rates of 60 sccm is introduced, and the furnace temperature is raised to 1500 ℃ at a heating rate of 5 ℃ / min. The holding time is 2~3 h. After the holding time is completed, the heating power is turned off, and the furnace is cooled to obtain Si3N4 nanowire film D. At the same time, carbon nanotubes are grown in situ on the surface of the cut Si3N4 nanowire film C, realizing the simultaneous preparation of flexible Si3N4 nanowire film and carbon nanotubes.

[0036] Figure 2 This demonstrates that the Si3N4 nanowire film prepared by high-temperature pyrolysis of polymer precursors possesses high flexibility. Macroscopically, the Si3N4 nanowire film can be wound around cylindrical objects. Microscopically, the Si3N4 nanowire film can be bent without damage.

[0037] Figure 3 This is a SEM image of carbon nanotubes formed on a Si3N4 nanowire film at 1000 °C in Example 3. The carbon nanotubes are entangled on the Si3N4 nanowire film and are evenly distributed on each nanowire.

[0038] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors, characterized in that, Includes the following steps: S1: Polysilazane, ferrocene and xylene are mixed evenly to obtain solution A. Solution A is then air-dried and cured, and then ground to obtain powder B as a precursor powder. The precursor powder is subjected to a first high-temperature heat treatment under nitrogen to obtain Si3N4 nanowire thin film. S2: The Si3N4 nanowire film is cut into several thin sheets of the same size. The precursor powder and several thin sheets are sequentially placed in a tube furnace along the gas flow direction, with the precursor powder at the center position between the gas inlet and the gas outlet. The several thin sheets are placed between the center position and the gas outlet. Nitrogen gas is then introduced for a second high-temperature heat treatment. The precursor powder generates Si3N4 nanowire film. The gas generated during the generation of Si3N4 nanowire film grows carbon nanotubes in situ on the surface of the thin sheets.

2. The method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors according to claim 1, characterized in that, In step S1, the mass ratio of polysilazane to ferrocene is (7-10):1; the volume ratio of xylene to polysilazane is (2-5):1; and the air-drying time is 5-8 days.

3. The method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors according to claim 1, characterized in that, In step S2, the flow rate of nitrogen gas introduced is 60~100 sccm.

4. The method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors according to claim 1, characterized in that, In S1 and S2, the first high-temperature heat treatment and the second high-temperature heat treatment are as follows: the furnace temperature is raised to 1300~1500 ℃ at a heating rate of 5~10 ℃ / min, and the holding time is 2~3 h.

5. The method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors according to claim 1, characterized in that, In step S2, the gases generated during the formation of the Si3N4 nanowire thin film include CO2, CO, and CH4.

6. The method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors according to claim 1, characterized in that, In S2, the plurality of thin plates are arranged at equal intervals.

7. The method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors according to claim 1, characterized in that, In step S2, the precursor powder is located in the temperature range of 1300~1500 ℃ in a tube furnace.

8. The method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors according to claim 1, characterized in that, The aforementioned thin sheets are respectively located in the temperature range of 1200 ℃ to 800 ℃ of the tube furnace.

9. The method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors according to claim 8, characterized in that, The aforementioned thin sheets are respectively located in the temperature ranges of 1200 ℃, 1000 ℃ and 800 ℃ of the tube furnace.

10. The method for simultaneously preparing flexible ceramic nanowire films and carbon nanotubes by high-temperature pyrolysis of polymer precursors according to claim 1, characterized in that, The carbon nanotubes in each Si3N4 nanowire film are intertwined and uniformly distributed.

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