A SnFe3N@carbon fiber composite material, its preparation method and application

Abstract

This invention discloses a SnFe3N@carbon fiber composite material, its preparation method, and its applications, belonging to the field of materials technology. The method involves mixing and stirring an organic solvent, polyacrylonitrile, dicyandiamine, tin salt, and iron salt until homogeneous, followed by electrospinning, low-temperature calcination, and high-temperature calcination to obtain the SnFe3N@carbon fiber composite material. The prepared SnFe3N@carbon fiber composite material exhibits excellent processing performance, electrical properties, good stability, high strength, and good conductivity, making it suitable as a magnetic material. This SnFe3N@carbon fiber composite material has high resistivity, a wide frequency range, and low cost, and is widely used in low-power pulse transformers. It can also be applied in the aerospace and electronic communications industries where ferrite cores with low core loss and high permeability are required.

Description

Technical Field

[0001] This invention belongs to the field of materials technology, specifically relating to a SnFe3N@carbon fiber composite material, its preparation method, and its application. Background Technology

[0002] In real-world experiments, fibrous carbon materials exhibit potential advantages. Carbon fiber, a fibrous carbon material, contains over 90% carbon in its chemical composition. It possesses advantages such as high specific modulus, high thermal / electrical conductivity, corrosion resistance, creep resistance, and a low coefficient of thermal expansion, making it suitable as both a structural and functional material, widely used in various materials and manufacturing processes. Magnetic materials, based on their chemical composition, commonly fall into two main categories: metallic magnetic materials and ferrites. Ferrites are magnetic oxides with iron oxide as their main component. Metallic magnetic materials include soft and hard magnetic materials. Soft magnetic materials have high permeability, are easily magnetized and demagnetized, have high initial magnetic susceptibility, high saturation magnetic induction, low coercivity (Hc), and narrow, long hysteresis loops with low losses, making them suitable for relays, motors, and magnetic cores and rods in various high-frequency electromagnetic components. Soft magnetic materials have weak remanence and are easily demagnetized, making them suitable for applications requiring repeated magnetization. They can be used to manufacture antenna ferrite rods for semiconductor radios, magnetic heads for tape recorders, memory elements in computers, and cores for transformers, alternators, electromagnets, and various high-frequency components. Common soft magnetic metallic materials include soft iron, silicon steel, and nickel-iron alloys. Common soft magnetic ferrites include manganese-zinc ferrite and nickel-zinc ferrite. Hard magnetic materials have strong remanence and are not easily demagnetized, making them suitable for permanent magnets. They are used in electrical equipment such as magnetoelectric instruments, loudspeakers, microphones, and permanent magnet motors. Common hard magnetic metallic materials include carbon steel, tungsten steel, and AlNiCo alloys. Common hard magnetic ferrites include barium ferrite and ferrite.

[0003] One existing method for preparing SnFe2O4 composite metal oxide involves using electrochemical deposition to synthesize a tin-iron composite metal oxide / reduced graphene oxide SnFe2O4@rGO to prepare an active material for the negative electrode of lithium-ion batteries. However, this material is only used in the negative electrode of lithium-ion batteries, has a narrow application range, is difficult to process, and has low strength.

[0004] In view of the problems of narrow application range, difficulty in processing and low strength of existing composite materials made of metallic magnetic materials and carbon fibers, there is an urgent need to find a new functional material with a wide range of applications between polymer materials and magnetic materials, and to apply it to aerospace, transformers and various soft magnetic fields. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a SnFe3N@carbon fiber composite material, its preparation method and application, so as to solve the technical problems of narrow application range, difficult processing and low strength of existing composite materials made of metallic magnetic materials and carbon fibers.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention discloses a method for preparing SnFe3N@carbon fiber composite material, comprising:

[0008] Organic solvent, polyacrylonitrile, dicyandiamine, tin salt and iron salt were mixed and stirred evenly, and then electrospun, calcined at low temperature and calcined at high temperature to obtain SnFe3N@carbon fiber composite material.

[0009] Preferably, the ratio of organic solvent: polyacrylonitrile: dicyandiamine: tin salt: iron salt is (10-15) mL: (1-1.5) g: (0.3-0.5) g: (1-2) mmol: (3-5) mmol.

[0010] Preferably, the organic solvent is a DMF solution, the tin salt is stannous chloride, tin methanesulfonate, tin ethanesulfonate, tin propanesulfonate, tin 2-propanesulfonate, tin hydroxymethanesulfonate, or tin 2-hydroxyethyl-1-sulfonate, and the iron salt is Fe(NO3). 2.9 H2O, FeCl3, Fe2(SO4)3 or Fe(NO3)3.

[0011] Preferably, the stirring temperature is 50–60°C; the stirring time is 2.5–3 h; and the stirring rate is 600–800 r / min.

[0012] Preferably, the voltage for electrospinning is 18–19 kV, and the flow rate is 0.3–0.5 mL / h.

[0013] Preferably, the low-temperature calcination temperature is 250–370°C, the low-temperature calcination time is 0.5–1.5 h, and the low-temperature calcination heating rate is 10–15°C / min.

[0014] Preferably, the high-temperature calcination temperature is 800–850°C, and the high-temperature calcination time is 2–2.5 h.

[0015] Preferably, the heating rate of the high-temperature calcination is 5-10°C / min; the high-temperature calcination is carried out in an argon atmosphere.

[0016] The present invention also discloses the SnFe3N@carbon fiber composite material prepared by the above preparation method.

[0017] This invention also discloses the application of the above-mentioned SnFe3N@carbon fiber composite material in the preparation of magnetic materials.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention discloses a method for preparing SnFe3N@carbon fiber composite material. An organic solvent, polyacrylonitrile, dicyandiamine, tin salt, and iron salt are mixed and stirred until homogeneous. After electrospinning, uniform white fibers are obtained. These fibers are then calcined at a low temperature to form black soft fibers. Finally, after high-temperature calcination, the black soft fibers form a carbon black soft cloth, yielding the SnFe3N@carbon fiber composite material. The prepared SnFe3N@carbon fiber composite material exhibits excellent processing performance, electrical properties, good stability, high strength, and good conductivity. It can be used as a magnetic material due to its high resistivity, wide frequency range, and low cost, making it widely applicable in low-power pulse transformers. It can also be used in the aerospace and electronic communications industries where ferrite cores with low core loss and high permeability are required.

[0020] This invention also discloses the SnFe3N@carbon fiber composite material prepared by the above-mentioned method. The SnFe3N@carbon fiber composite material has high remanence, coercivity and maximum energy product, is not easily broken, has good mechanical properties, and low alloy density, which is conducive to the miniaturization, thinning, miniaturization and ultra-miniaturization of magnetic components. The obtained SnFe3N@carbon fiber composite material has high magnetic flux, good hysteresis loop parameters, and a wide range of applications. It can be used in the electronic communication industry and can meet the requirements of miniaturization and high efficiency of electrical equipment.

[0021] This invention also discloses the application of the aforementioned SnFe3N@carbon fiber composite material in the preparation of magnetic materials. When applied to magnetic materials, this SnFe3N@carbon fiber composite material can convert magnetic energy into mechanical energy, and vice versa. From the perspective of its composition, this magnetic functional composite material is a functional material that lies between polymer materials and magnetic materials, and it has guiding significance for research in interdisciplinary or cross-disciplinary fields. Attached Figure Description

[0022] Figure 1 This is a scanning electron microscope image at low magnification of the SnFe3N@carbon fiber composite material prepared in Example 1 of the present invention;

[0023] Figure 2 This is a high-magnification scanning electron microscope image of the SnFe3N@carbon fiber composite material prepared in Example 1 of the present invention.

[0024] Figure 3 The image shows the XRD pattern of the SnFe3N@carbon fiber composite material prepared in Example 1 of this invention. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0026] Unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0027] Unless otherwise specified, all the technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0028] In this invention, unless otherwise specified, percentage (%) or parts refer to weight percentage or parts relative to the composition.

[0029] Unless otherwise specified, the components or preferred components involved in this invention can be combined with each other to form new technical solutions.

[0030] In this invention, unless otherwise specified, the numerical range "a~b" represents an abbreviation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "6~22" means that all real numbers between "6~22" have been listed in this document, and "6~22" is simply an abbreviation of these numerical combinations.

[0031] The "scope" disclosed in this invention can be in the form of a lower limit and an upper limit, and can be one or more lower limits and one or more upper limits, respectively.

[0032] In this invention, the term "and / or" as used herein refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations.

[0033] In this invention, unless otherwise stated, the various reaction or operation steps may be performed sequentially or in a particular order. Preferably, the reaction methods described herein are performed sequentially.

[0034] Unless otherwise stated, the technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods or materials similar to or equivalent to those described herein may also be used in this invention.

[0035] This invention provides a method for preparing SnFe3N@carbon fiber composite material, comprising the following steps:

[0036] S1. Add 10-15 mL of organic solvent to a glass bottle, then add a magnetic stir bar to obtain solution A;

[0037] S2. Weigh 1-1.5g of PAN (polyacrylonitrile) and pour it into solution A, then stir evenly for 2-5 minutes to obtain solution B;

[0038] S3. Weigh 0.3-0.5g of DCD (dicyandiamine) and pour it into solution B. Stir evenly for 2-5 minutes to obtain solution C.

[0039] S4. Weigh 1-2 mmol of tin salt and 3-5 mmol of iron salt and pour them evenly into solution C;

[0040] S5. Place solution C on a stirrer, set the temperature to 50-60℃ and the stirring speed to 600-800 r / min; stir evenly for 2.5-3 hours to obtain solution D.

[0041] S6. Place the obtained solution D on an electrospinning device, set the voltage of the electrospinning machine to 18-19KV and the flow rate to 0.3-0.5mL / h. After electrospinning is completed, SnFe3N@ fiber composite material 1 can be obtained.

[0042] S7. The obtained SnFe3N@fiber composite material 1 is heated to 250-370℃ in an air furnace at a heating rate of 10-15℃ / min and calcined for 0.5-1.5h to obtain SnFe3N@carbon fiber composite material 2.

[0043] S8. The SnFe3N@carbon fiber composite material 2 obtained in S7 is placed in an argon furnace and heated at a rate of 5-10℃ / min until it reaches 800-850℃. Then, it is calcined in an argon atmosphere for 2-2.5 hours to finally obtain the SnFe3N@carbon fiber composite material.

[0044] The organic solvent is DMF (N,N-dimethylformamide);

[0045] The tin salts are stannous chloride, tin methanesulfonate, tin ethanesulfonate, tin propanesulfonate, tin 2-propanesulfonate, tin hydroxymethanesulfonate, or tin 2-hydroxyethyl-1-sulfonate;

[0046] Iron salts are Fe(NO3). 2.9 H2O, FeCl3, Fe2(SO4)3 or Fe(NO3)3.

[0047] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0048] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0049] The present invention will now be described in further detail with reference to the accompanying drawings:

[0050] Example 1

[0051] A method for preparing SnFe3N@carbon fiber composite material includes the following steps:

[0052] Weigh 12 mL of DMF solution, 1.2 g of PAN, 0.3 g of DCD, 1 mmol of SnCl2, and 3 mmol of Fe(NO3). 2.9 H2O was stirred vigorously at 700 r / min for 2.5 h at 50 °C until homogeneous; the above solution mixture was loaded into an injection device and electrospun at 18 KV and 0.3 mL / h to obtain SnFe3N@ fiber composite material 1.

[0053] SnFe3N@fiber composite material 1 was cut into long blocks and placed in an air furnace at 10℃ / min. The temperature was raised to 250℃ and calcined at 250℃ for 1 hour to obtain a cloth-like material SnFe3N@carbon fiber composite material 2 at low temperature.

[0054] Finally, the obtained SnFe3N@carbon fiber composite material 2 was heated in an argon furnace at a heating rate of 5℃ / min for 160 min, then heated to 800℃, and calcined at a constant temperature of 800℃ for 2 h. Finally, the temperature was allowed to drop to room temperature to obtain the SnFe3N@carbon fiber composite material.

[0055] See Figure 1 This is a scanning electron microscope image of the SnFe3N@carbon fiber composite material prepared in Example 1 of the present invention at low magnification. Figure 2 This is a high-magnification scanning electron microscope image of the SnFe3N@carbon fiber composite material prepared in Example 1 of the present invention. As can be seen from the image, the SnFe3N@carbon fiber composite material prepared under high-temperature argon furnace has a carbon fiber structure of varying thickness, and SnFe3N is attached to the carbon fiber structure.

[0056] See Figure 3 The image shows the XRD pattern of the SnFe3N@carbon fiber composite material prepared in Example 1 of this invention. As can be seen from the image, the SnFe3N@carbon fiber composite material was successfully prepared simply and efficiently through the preparation steps disclosed in this invention.

[0057] Example 2

[0058] A method for preparing SnFe3N@carbon fiber composite material includes the following steps:

[0059] Weigh 10 mL of DMF, 1 g of PAN, 0.4 g of DCD, 1.5 mmol of SnCl2, and 3.5 mmol of Fe(NO3). 2.9 H2O was stirred vigorously at 52°C and 600 r / min for 3 h to mix evenly; the above solution mixture was loaded into an injection device and electrospun at 18 KV and 0.3 mL / h to obtain mixed fiber cloth SnFe3N@fiber composite material 1.

[0060] SnFe3N@fiber composite material 1 was cut into long blocks, placed in an air furnace and heated to 270℃ at a rate of 12℃ / min. It was then calcined at 270℃ for 0.5h. After that, it was heated to 810℃ in an argon furnace at a rate of 6℃ / min and then calcined at a constant temperature of 810℃ for 2.5h. The temperature was then lowered to room temperature to obtain SnFe3N@carbon fiber composite material.

[0061] Example 3

[0062] A method for preparing SnFe3N@carbon fiber composite material includes the following steps:

[0063] Weigh 12 mL of DMF, 1.3 g of PAN, 0.5 g of DCD, 1.2 mmol of SnCl2, and 4 mmol of Fe(NO3). 2.9H2O was stirred vigorously at 55°C and 650 r / min for 2.6 h to mix evenly; the above solution mixture was loaded into an injection device and electrospun at 18 KV and 0.3 mL / h to obtain mixed fiber cloth SnFe3N@ fiber composite material 1.

[0064] SnFe3N@ fiber composite material 1 was cut into long blocks, placed in an air furnace and heated to 300℃ at a rate of 13℃ / min. It was then calcined at 300℃ for 1 hour. Then, it was heated to 820℃ in an argon furnace at a rate of 7℃ / min and calcined at a constant temperature of 820℃ for 2 hours. After cooling to room temperature, SnFe3N@ carbon fiber composite material was obtained.

[0065] Example 4

[0066] A method for preparing SnFe3N@carbon fiber composite material includes the following steps:

[0067] Weigh 13 mL of DMF, 1.4 g of PAN, 0.4 g of DCD, 1.8 mmol of tin methanesulfonate, and 4.5 mmol of Fe(NO3). 2.9 H2O was stirred vigorously at 750 r / min for 2.8 h at 58 °C until homogeneous; the above solution mixture was loaded into an injection device and electrospun at 19 KV and 0.4 mL / h to obtain the mixed fiber cloth SnFe3N@fiber composite material 1.

[0068] SnFe3N@fiber composite material 1 was cut into long blocks, placed in an air furnace and heated to 350℃ at a rate of 14℃ / min, and calcined at 350℃ for 1.5h. Then, it was heated to 830℃ in an argon furnace at a heating rate of 8℃ / min, and then calcined at a constant temperature of 830℃ for 2.2h. After cooling to room temperature, SnFe3N@carbon fiber composite material was obtained.

[0069] Example 5

[0070] A method for preparing SnFe3N@carbon fiber composite material includes the following steps:

[0071] Weigh 15 mL of DMF, 1.5 g of PAN, 0.3 g of DCD, 2 mmol of tin ethanesulfonate, and 5 mmol of Fe(NO3). 2.9 H2O was stirred vigorously at 800 r / min for 3 h at 60 °C until homogeneous; the above solution mixture was loaded into an injection device and electrospun at 19 KV and 0.5 mL / h to obtain mixed fiber cloth SnFe3N@ fiber composite material 1.

[0072] SnFe3N@ fiber composite material 1 was cut into long blocks, placed in an air furnace and heated to 370℃ at a rate of 15℃ / min. It was then calcined at 370℃ for 1 hour. In an argon furnace, the temperature was increased to 850℃ at a rate of 10℃ / min, and then calcined at a constant temperature of 850℃ for 2 hours. The temperature was then reduced to room temperature to obtain SnFe3N@ carbon fiber composite material.

[0073] Example 6

[0074] A method for preparing SnFe3N@carbon fiber composite material includes the following steps:

[0075] Weigh 11 mL of DMF, 1.1 g of PAN, 0.4 g of DCD, 1.1 mmol of tin propanesulfonate, and 3.5 mmol of Fe(NO3)3. Mix them thoroughly by vigorous mechanical stirring at 600 r / min for 2.7 h at 51 °C. The mixture is then loaded into an injection device and electrospun at 18 KV and 0.3 mL / h to obtain the mixed fiber cloth SnFe3N@fiber composite material 1.

[0076] SnFe3N@fiber composite material 1 was cut into long blocks, placed in an air furnace and heated to 260℃ at a rate of 11℃ / min. It was then calcined at 260℃ for 0.5h. After that, it was heated to 840℃ in an argon furnace at a rate of 9℃ / min, and then calcined at a constant temperature of 840℃ for 2.1h. After cooling to room temperature, SnFe3N@carbon fiber composite material was obtained.

[0077] Example 7

[0078] A method for preparing SnFe3N@carbon fiber composite material includes the following steps:

[0079] Weigh 10 mL of DMF, 1 g of PAN, 0.4 g of DCD, 1.3 mmol of tin 2-propanesulfonate, and 3.5 mmol of FeCl3. Mix them thoroughly by vigorous mechanical stirring at 600 r / min for 2.9 h at 53 °C. The mixture is then loaded into an injection device and electrospun at 18 KV and 0.3 mL / h to obtain the mixed fiber cloth SnFe3N@fiber composite material 1.

[0080] SnFe3N@fiber composite material 1 was cut into long blocks, placed in an air furnace and heated to 280℃ at a rate of 12℃ / min. It was then calcined at 280℃ for 0.5h. After that, it was heated to 810℃ in an argon furnace at a rate of 6℃ / min, and then calcined at a constant temperature of 810℃ for 2.3h. After cooling to room temperature, SnFe3N@carbon fiber composite material was obtained.

[0081] Example 8

[0082] A method for preparing SnFe3N@carbon fiber composite material includes the following steps:

[0083] Weigh 10 mL of DMF, 1 g of PAN, 0.4 g of DCD, 1.4 mmol of tin hydroxymethanesulfonate, and 3.5 mmol of Fe(NO3)3. Mix them thoroughly by vigorous mechanical stirring at 600 r / min for 3 h at 54 °C. The mixture is then loaded into an injection device and electrospun at 18 KV and 0.3 mL / h to obtain the mixed fiber cloth SnFe3N@fiber composite material 1.

[0084] SnFe3N@fiber composite material 1 was cut into long blocks, placed in an air furnace and heated to 290℃ at a rate of 12℃ / min, and calcined at 290℃ for 0.5h. Then, it was heated to 810℃ in an argon furnace at a heating rate of 6℃ / min, and then calcined at a constant temperature of 810℃ for 2.4h. After cooling to room temperature, SnFe3N@carbon fiber composite material was obtained.

[0085] Example 9

[0086] A method for preparing SnFe3N@carbon fiber composite material includes the following steps:

[0087] Weigh 12 mL of DMF, 1.3 g of PAN, 0.5 g of DCD, 1.6 mmol of 2-hydroxyethyl-1-sulfonated tin, and 4 mmol of Fe2(SO4)3. Mix them thoroughly by vigorous mechanical stirring at 650 r / min for 2.6 h at 56 °C. The mixture is then loaded into an injection device and electrospun at 18 KV and 0.3 mL / h to obtain the mixed fiber cloth SnFe3N@fiber composite material 1.

[0088] SnFe3N@ fiber composite material 1 was cut into long blocks, placed in an air furnace and heated to 320°C at a rate of 13°C / min. It was then calcined at 320°C for 1 hour. In an argon furnace, the temperature was increased to 820°C at a rate of 7°C / min, and then calcined at a constant temperature of 820°C for 2 hours. The temperature was then reduced to room temperature to obtain SnFe3N@ carbon fiber composite material.

[0089] Example 10

[0090] A method for preparing SnFe3N@carbon fiber composite material includes the following steps:

[0091] Weigh 13 mL of DMF, 1.4 g of PAN, 0.4 g of DCD, 1.7 mmol of SnCl2, and 4.5 mmol of FeCl3. Mix them thoroughly by vigorous mechanical stirring at 750 r / min for 2.8 h at 57 °C. The mixture is then loaded into an injection device and electrospun at 19 KV and 0.4 mL / h to obtain the mixed fiber cloth SnFe3N@fiber composite material 1.

[0092] SnFe3N@fiber composite material 1 was cut into long blocks, placed in an air furnace and heated to 360℃ at a rate of 14℃ / min, and calcined at 360℃ for 1.5h. Then, it was heated to 830℃ in an argon furnace at a heating rate of 8℃ / min, and then calcined at a constant temperature of 830℃ for 2.2h. After cooling to room temperature, SnFe3N@carbon fiber composite material was obtained.

[0093] The obtained SnFe3N@carbon fiber composite material exhibits excellent electrical conductivity, thermal conductivity, and ductility, demonstrating superior performance and promising applications in other fields. This SnFe3N@carbon fiber composite material boasts high purity and easily controllable material composition. Material synthesis and preparation involve obtaining chemically and structurally different materials from various gaseous, liquid, or solid raw materials through specific methods. Advantages include high purity, easily controllable material composition, diverse components, good uniformity, and diverse material shapes. Furthermore, it can be synthesized and densified at relatively low temperatures. The obtained SnFe3N@carbon fiber composite material exhibits high magnetic flux, good hysteresis loop parameters, and a wide range of applications.

[0094] In the field of electronics, the SnFe3N@carbon fiber composite material prepared by this invention is widely used as a magnetic material in magnetic memory, inductors, and magnetic sensors. Magnetic memory is an important application of magnetic materials, enabling data storage and retrieval by controlling and altering the magnetic properties of the material.

[0095] In the field of communication technology, the SnFe3N@carbon fiber composite material prepared by this invention is used as a magnetic material, primarily in inductors and sensors. Inductors utilize the magnetic properties of magnetic materials to sense and transmit current and voltage, serving functions such as filtering, compensation, and signal processing. Sensors, on the other hand, convert changes in the magnetic properties of the magnetic material into electrical signals for detection and measurement.

[0096] The SnFe3N@carbon fiber composite material prepared by this invention is a new generation of composite material with high strength, long life and corrosion resistance. Combining the preparation theories and methods of difficult-to-process materials and special performance materials, a new theory and new process are finally formed, and a reduced-weight forming process and new product development are realized.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing SnFe3N@carbon fiber composite material, characterized in that, include: Organic solvent, polyacrylonitrile, dicyandiamide, tin salt and iron salt were mixed and stirred evenly, and then electrospun, calcined at low temperature and calcined at high temperature to obtain SnFe3N@carbon fiber composite material. The ratio of the organic solvent: polyacrylonitrile: dicyandiamine: tin salt: iron salt is (10~15) mL: (1~1.5) g: (0.3~0.5) g: (1~2) mmol: (3~5) mmol; The organic solvent is a DMF solution, the tin salt is stannous chloride, tin methanesulfonate, tin ethanesulfonate, tin propanesulfonate, tin 2-propanesulfonate, tin hydroxymethanesulfonate, or tin 2-hydroxyethyl-1-sulfonate, and the iron salt is Fe(NO3). 2.9 H2O, FeCl3, Fe2(SO4)3 or Fe(NO3)3; The low-temperature calcination temperature is 250~370℃, and the low-temperature calcination time is 0.5~1.5h; The high-temperature calcination is carried out at a temperature of 800~850℃ for 2~2.5h.

2. The method for preparing SnFe3N@carbon fiber composite material according to claim 1, characterized in that, The stirring temperature is 50~60℃; the stirring time is 2.5~3h; and the stirring rate is 600~800r / min.

3. The method for preparing SnFe3N@carbon fiber composite material according to claim 1, characterized in that, The electrospinning voltage is 18~19KV; the flow rate is 0.3~0.5mL / h.

4. The method for preparing SnFe3N@carbon fiber composite material according to claim 1, characterized in that, The heating rate for low-temperature calcination is 10~15℃ / min.

5. The method for preparing SnFe3N@carbon fiber composite material according to claim 1, characterized in that, The heating rate of the high-temperature calcination is 5~10℃ / min.

6. The SnFe3N@carbon fiber composite material prepared by any one of claims 1 to 5.

7. The application of the SnFe3N@carbon fiber composite material according to claim 6 in the preparation of magnetic materials.

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