Wave-absorbing material of nitrogen-doped carbon-coated FeNi alloy with flammulina velutipes structure as well as preparation method and application of wave-absorbing material
By preparing nitrogen-doped carbon-coated FeNi alloy microwave absorbing materials with a mushroom-like structure, the problem that existing materials cannot meet the requirements of wide-band and high-efficiency electromagnetic absorption was solved, and excellent microwave absorption performance was achieved.
Patent Information
- Application Number
- CN202410965979.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-18
- Publication Date
- 2026-01-20
AI Technical Summary
Existing microwave attenuation materials cannot meet the requirements of wide-bandwidth and high-efficiency electromagnetic absorption, and the materials must have excellent electromagnetic impedance matching characteristics, electromagnetic loss performance, light weight, corrosion resistance and moisture resistance.
A nitrogen-doped carbon-coated FeNi alloy with a mushroom-like structure was used to prepare a microwave absorbing material through hydrothermal reaction and annealing. This process formed a spherical FeNi alloy core and a nitrogen-doped carbon coating layer, which, combined with mesoporous and rod-like structures, created a perfect spatial conductive network.
It achieves wideband and high-efficiency electromagnetic wave absorption by combining dielectric and magnetic properties to reduce conductivity and magnetic loss, thus achieving excellent microwave absorption performance.
Smart Images
Figure CN121362567A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of electromagnetic functional materials, and particularly relates to a nitrogen-doped carbon-coated FeNi alloy wave-absorbing material with a golden needle mushroom structure, a preparation method and application thereof. BACKGROUND
[0002] With the rapid development of the electronic industry, the number of wireless communication systems and high-frequency electronic devices has increased dramatically, and the problems of electromagnetic interference and electromagnetic pollution have become increasingly prominent. The worsening electromagnetic environment not only affects the communication field, but also brings significant harm to people's production and life. In the military field, the rapid development of detection technology and precision-guided weapons has greatly threatened the survival of weapons and the improvement of military capabilities. This has put forward higher and higher requirements for microwave technology and microwave absorbing materials. The existing microwave attenuation materials cannot fully meet the increasingly stringent application requirements. In order to obtain a wave-absorbing material with excellent performance, it is necessary to have excellent electromagnetic impedance matching characteristics and electromagnetic loss performance to broaden the absorption frequency band and improve the absorption rate, and the material also needs to have the characteristics of light weight, thin absorbing layer, good corrosion resistance, and moisture resistance. Therefore, developing new types of broadband and efficient microwave absorbing materials has become an urgent and challenging task in the field of science and technology. The nitrogen-doped carbon-coated FeNi alloy with a golden needle mushroom structure can meet the requirements of broadband and high efficiency of microwave absorbing materials. SUMMARY
[0003] In view of the above technical problems, the present application provides a preparation method of a nitrogen-doped carbon-coated FeNi alloy wave-absorbing material with a golden needle mushroom structure, which is used to solve the above technical problems.
[0004] The technical scheme adopted by the present application is as follows:
[0005] A wave-absorbing material, which comprises a nitrogen-doped carbon-coated FeNi alloy.
[0006] According to an embodiment of the present application, the wave-absorbing material has a golden needle mushroom structure, which comprises a spherical structure and a rod-like structure directly connected to the spherical structure.
[0007] According to an embodiment of the present application, the spherical structure comprises a core structure composed of FeNi alloy, and a nitrogen-doped carbon coating layer coated on the surface of the FeNi alloy.
[0008] According to an embodiment of the present application, the core structure has a mesoporous structure.
[0009] According to an embodiment of the present application, the component of the rod-like structure comprises nitrogen and carbon.
[0010] According to embodiments of the present application, the size of the spherical structure is 30-200 nm, for example, 50 nm, 100 nm, 150 nm.
[0011] According to embodiments of the present application, the rod diameter of the rod-shaped structure is 10-100 nm, for example, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm.
[0012] According to embodiments of the present application, the length of the rod-shaped structure is 10-1000 nm, for example, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 1000 nm.
[0013] According to embodiments of the present application, the needle mushroom structure has a large aspect ratio, and the aspect ratio is 1-50, for example, 10-30.
[0014] The present application also provides a preparation method of the above wave-absorbing material, and the preparation method comprises the following steps:
[0015] S1) dissolving a nickel source and a carbon source in a first part of a nitrogen-containing solvent to obtain an A solution;
[0016] S2) dissolving an iron source in a second part of the nitrogen-containing solvent to obtain a B solution;
[0017] S3) uniformly mixing the A solution and the B solution, adding an alkali solution, and performing preheating treatment to obtain a mixed solution;
[0018] S4) after the mixed solution is subjected to hydrothermal reaction, cooling and collecting the precipitate;
[0019] S5) after the precipitate is subjected to annealing treatment, the wave-absorbing material is obtained.
[0020] According to embodiments of the present application, the nickel source is selected from at least one of nickel acetate tetrahydrate, nickel chloride hexahydrate, and nickel nitrate hexahydrate.
[0021] According to embodiments of the present application, the iron source is selected from potassium ferricyanide.
[0022] According to embodiments of the present application, the carbon source is selected from at least one of polyvinylpyrrolidone, glucose, and sucrose.
[0023] According to embodiments of the present application, the nitrogen-containing solvent is selected from N,N-dimethylformamide and propylenediamine.
[0024] According to embodiments of the present application, in step S1, the molar ratio of the nickel source, the carbon source, and the first part of the nitrogen-containing solvent is 0.1-10:1-20:100-300, for example, 1:10:200.
[0025] According to the embodiments of the present application, in step S2, the molar ratio of the potassium ferricyanide to the second part of the nitrogen-containing solvent is 0.1:10-50, for example, 1:30.
[0026] According to the embodiments of the present application, in step S3, the molar ratio of the nickel source, the carbon source and the iron source is 1-10:1-100:1-10, for example, 3:30:2.
[0027] According to the embodiments of the present application, in step S3, the basic solution is, for example, a NaOH solution (the concentration of NaOH is, for example, 1 mol L -1 ), a KOH (the concentration of KOH is, for example, 1 mol L -1 ).
[0028] According to the embodiments of the present application, in step S3, the volume ratio of the mixture of the A solution and the B solution to the volume of the basic solution is 1-20:1, for example, 10:1.
[0029] According to the embodiments of the present application, in step S3, the pre-heating treatment is performed at 50-100°C for 1-10h, for example, at 85°C for 4h.
[0030] According to the embodiments of the present application, in step S4, the hydrothermal reaction is performed at 150-250°C for 10-100h, for example, at 190°C for 72h.
[0031] According to the embodiments of the present application, in step S4, the hydrothermal reaction is performed in a hydrothermal reactor, for example, a reactor with a polytetrafluoroethylene lining.
[0032] According to the embodiments of the present application, in step S4, the cooling can be performed by any method known in the art, which is not specifically limited in the present application.
[0033] According to the embodiments of the present application, in step S4, the collection of the precipitate can be performed by any method known in the art, for example, by centrifugation.
[0034] According to the embodiments of the present application, in step S4, after the collection of the precipitate, the precipitate can be washed, dried and ground. Preferably, the precipitate is washed to neutral.
[0035] According to the embodiments of the present application, the precipitate obtained in step S4 comprises a FeNi precursor, and the surface of the FeNi precursor is loaded with the carbon source and the nitrogen-containing solvent.
[0036] According to an embodiment of the present application, in step S5, the conditions of the annealing treatment include: annealing at 700-1000℃ in an Ar atmosphere for 2h, with a heating rate of 5℃ / min.
[0037] According to an embodiment of the present application, in step S5, during the annealing treatment, the FeNi precursor becomes a FeNi alloy with a spherical structure, and the carbon source and nitrogen-containing solvent loaded on the surface of the FeNi precursor are converted into a nitrogen-doped carbon coating layer; the FeNi alloy acts as a catalyst to promote the carbon in the nitrogen-doped carbon coating layer to grow in a rod-like structure along a direction perpendicular to the contact surface between the FeNi alloy and the carbon coating layer.
[0038] The present application also provides an application of the above-mentioned wave-absorbing material in electromagnetic functional materials.
[0039] According to an embodiment of the present application, the electromagnetic functional material comprises the above-mentioned wave-absorbing material.
[0040] Advantages
[0041] The wave-absorbing material of the nitrogen-doped carbon-coated FeNi alloy prepared by the present application has a golden needle mushroom structure, and the mesoporous structure in the spherical structure is conducive to the reflection and scattering of electromagnetic waves, and promotes the attenuation of electromagnetic energy; and the amorphous carbon coating layer coated on the surface of the FeNi alloy particles can promote the interfacial polarization loss.
[0042] The golden needle mushroom structure of the present application has a large aspect ratio, and the amorphous carbon coating layer in the spherical structure cooperates with the rod-like structure to form a perfect space conductive network structure, providing a channel for the migration and diffusion of electrons and promoting the conductance loss.
[0043] The nitrogen element doped in the wave-absorbing material of the present application can further promote the formation of dipoles and enhance the polarization loss; at the same time, the FeNi alloy has excellent magnetic properties and promotes the magnetic loss.
[0044] The wave-absorbing material of the present application has a nitrogen-doped carbon coating layer with dielectric properties and a FeNi alloy with magnetic properties, which can obtain excellent impedance matching characteristics; and the golden needle mushroom structure of the wave-absorbing material of the present application has a large aspect ratio, forming a perfect space conductive network structure, providing a channel for the migration and diffusion of electrons and promoting the conductance loss, which is conducive to the reflection and scattering of electromagnetic waves, realizing efficient attenuation of electromagnetic energy and achieving the purpose of attenuating electromagnetic waves, so excellent microwave absorption performance can be realized. BRIEF DESCRIPTION OF DRAWINGS
[0045] Figure 1 A flowchart of preparing the wave-absorbing material of the nitrogen-doped carbon-coated FeNi alloy with a golden needle mushroom structure according to Example 1 of the present application is shown in the figure;
[0046] Figure 2A transmission electron microscope image of the nitrogen-doped carbon-coated FeNi alloy with a needle mushroom structure prepared in Example 1 of the present application;
[0047] Figure 3 A scanning electron microscope image of the nitrogen-doped carbon-coated FeNi alloy with a needle mushroom structure prepared in Example 1 of the present application;
[0048] Figure 4 A scanning electron microscope image of the nitrogen-doped carbon-coated FeNi alloy with a needle mushroom structure prepared in Example 4 of the present application;
[0049] Figure 5 A scanning electron microscope image of the carbon-coated FeNi alloy prepared in Comparative Example 1 of the present application;
[0050] Figure 6 A scanning electron microscope image of the carbon-coated FeNi alloy prepared in Comparative Example 2 of the present application;
[0051] Figure 7 An EDS image of the nitrogen-doped carbon-coated FeNi alloy with a needle mushroom structure prepared in Test Example 1 of the present application;
[0052] Figure 8 A wave-absorbing performance image of the nitrogen-doped carbon-coated FeNi alloy with a needle mushroom structure prepared in Application Example 1 of the present application. DETAILED DESCRIPTION
[0053] The technical solutions of the present application will be further described in detail below in combination with specific embodiments. It should be understood that the following embodiments are only illustratively described and explained, and should not be interpreted as limiting the scope of protection of the present application. Any technology realized based on the above description of the present application is covered within the scope of protection intended by the present application.
[0054] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.
[0055] Example 1
[0056] The preparation method of the wave-absorbing material of the nitrogen-doped carbon-coated FeNi alloy with a needle mushroom structure is as follows:
[0057] S1, dissolve nickel acetate tetrahydrate and polyvinylpyrrolidone in N,N-dimethylformamide to obtain solution A, wherein the molar ratio of nickel acetate tetrahydrate, polyvinylpyrrolidone and N,N-dimethylformamide is 1:10:200;
[0058] S2, dissolve potassium ferricyanide in N,N-dimethylformamide to obtain solution B, wherein the molar ratio of potassium ferricyanide and N,N-dimethylformamide is 1:30;
[0059] S3, the A solution and the B solution are uniformly mixed under magnetic stirring, 1M NaOH solution is added, the volume ratio of the A solution and the B solution after mixing to the volume of the NaOH solution is 10:1, and the mixture is stirred at 85°C for 4h;
[0060] S4, the solution is transferred to a reaction kettle with a polytetrafluoroethylene liner, and is kept at 190°C for 72h;
[0061] S5, after the reaction kettle is cooled to room temperature, the precipitate is collected by centrifugation, and the precipitate is washed, dried, and ground into powder;
[0062] S6, the powder is annealed at 700-1000°C (preferably 800°C in this embodiment) in an Ar atmosphere for 2h at a heating rate of 5°C / min, to obtain a nitrogen-doped carbon-coated FeNi alloy wave-absorbing material.
[0063] The nitrogen-doped carbon-coated FeNi alloy wave-absorbing material prepared in this embodiment has a golden needle mushroom structure, and specifically:
[0064] The inventors believe that in this embodiment, metal ions undergo coprecipitation with metal hexacyanide ions to form FeNi precursors. Polyvinylpyrrolidone has hydrophobic vinyl groups and hydrophilic carboxyl groups, which can cause the formation of polarized nuclei: the crystal nuclei formed in the early stage of the FeNi precursor are adsorbed on the carboxyl groups of polyvinylpyrrolidone, and then gradually accumulate closely together; with further reaction, these nanocrystals accumulate into monodisperse nanospheres through the lamer mechanism. During the reaction, polyvinylpyrrolidone plays a very important role in adjusting the morphology and preventing particle agglomeration, which is mainly due to the steric hindrance effect of the hydrophobic carbon chain of polyvinylpyrrolidone, which effectively hinders the aggregation of particles, and forms a mesoporous structure between particles and particles; on the other hand, polyvinylpyrrolidone can uniformly adhere to the surface of the FeNi precursor to form a coating layer. At a high temperature of 190°C, the N atoms in N,N-dimethylformamide are connected to polyvinylpyrrolidone to form nitrogen doping. After annealing, N,N-dimethylformamide and polyvinylpyrrolidone attached to the surface of the FeNi precursor are carbonized to form a uniform nitrogen-doped amorphous carbon coating layer, as shown in Figure 2 After annealing, the FeNi precursor becomes a FeNi alloy with a spherical structure coated with a nitrogen-doped carbon coating layer, and acts as a catalyst to promote the rapid growth of carbon along the direction perpendicular to the contact surface between FeNi and the carbon coating layer, forming a rod-shaped structure, thus forming a golden needle mushroom structure, as shown in Figure 3 The size of the spherical structure is 50-100nm, and the length of the rod-shaped structure is 500-1000nm, and the rod diameter is 30-50nm.
[0065] Example 2
[0066] This example is substantially the same as example 1, except that:
[0067] In step S3, the molar ratio of the nickel acetate tetrahydrate, polyvinylpyrrolidone and potassium ferricyanide in the A solution and the B solution added is 2:30:3. The nitrogen-doped carbon-coated FeNi alloy wave-absorbing material prepared in this example has a golden needle mushroom structure, the size of the spherical structure is 50-100 nm, the length of the rod-shaped structure is 300-600 nm, and the rod diameter is 30-50 nm.
[0068] Example 3
[0069] This example is substantially the same as example 1, except that:
[0070] In step S4, the reaction condition is 250°C for 72h. The nitrogen-doped carbon-coated FeNi alloy wave-absorbing material prepared in this example has a golden needle mushroom structure, the size of the spherical structure is 80-150 nm, the length of the rod-shaped structure is 300-1000 nm, and the rod diameter is 50-100 nm.
[0071] Example 4
[0072] This example is substantially the same as example 1, except that:
[0073] In step S6, the powder is annealed at 900°C in an Ar atmosphere for 2h. The nitrogen-doped carbon-coated FeNi alloy wave-absorbing material prepared in this example has a golden needle mushroom structure, as shown in FIG. 2, the size of the spherical structure is 100-200 nm, the length of the rod-shaped structure is 300-1000 nm, and the rod diameter is 30-60 nm. Figure 4
[0074] It can be known through testing that the nitrogen-doped carbon-coated FeNi alloy wave-absorbing materials prepared in examples 2-4 all have a golden needle mushroom structure.
[0075] Comparative Example 1
[0076] This comparative example is substantially the same as example 1, except that: in step S6, the powder is annealed at 1050°C in an Ar atmosphere for 2h, and the nitrogen-doped carbon-coated FeNi alloy wave-absorbing material of this comparative example is obtained. The scanning electron microscope result of this comparative example is shown in FIG. 3, and it can be seen that this comparative example fails to obtain a golden needle mushroom structure. Figure 5
[0077] Comparative Example 2
[0078] This comparative example is substantially the same as example 1, except that: in step S4, the reaction condition is 300°C for 72h, and the nitrogen-doped carbon-coated FeNi alloy wave-absorbing material of this comparative example is obtained. The scanning electron microscope result of this comparative example is shown in FIG. 4. Figure 6 As shown, it can be seen that the comparative example fails to obtain a golden needle mushroom structure.
[0079] Test Example 1
[0080] The wave-absorbing material of the nitrogen-doped carbon-coated FeNi alloy prepared in Example 1 was taken for element determination, and the test results are shown in Table 1. Figure 7 Figure 7 It can be known that the material prepared in the application contains C, O, Fe, Ni and N elements, the C element comes from amorphous carbon, the O element comes from the functional groups in the amorphous carbon, the Fe and Ni come from the FeNi alloy, and the existence of the N element indicates that the N is doped into the amorphous carbon.
[0081] The rod-shaped structure and the spherical structure on the wave-absorbing material of the nitrogen-doped carbon-coated FeNi alloy prepared in Example 1 were taken for element determination, respectively, and the test results are as follows: the rod-shaped structure contains C, O and N elements, and the spherical structure contains C, O, Fe, Ni and N elements.
[0082] Application Example 1
[0083] The wave-absorbing material of the nitrogen-doped carbon-coated FeNi alloy prepared in Example 1 was taken for microwave absorption performance test, and the results are shown in Table 2. Figure 8
[0084] The above illustrates the exemplary embodiments of the application. However, the protection scope of the application is not limited to the above-mentioned embodiments. Any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principles of the application shall be included in the protection scope of the application.
Claims
1. A wave-absorbing material, characterized by, The wave-absorbing material comprises a nitrogen-doped carbon-coated FeNi alloy. The wave-absorbing material has a golden needle mushroom structure, and the golden needle mushroom structure comprises a spherical structure and a rod-shaped structure directly connected to the spherical structure.
2. The wave-absorbing material according to claim 1, characterized in that, The spherical structure comprises a core structure of FeNi alloy and a nitrogen-doped carbon coating layer coated on the surface of the FeNi alloy. Preferably, the core structure has a mesoporous structure. Preferably, the component of the rod-shaped structure comprises nitrogen and carbon.
3. The wave-absorbing material according to claim 1 or 2, characterized in that, The size of the spherical structure is 30-200 nm. Preferably, the rod diameter of the rod-shaped structure is 10-100 nm. Preferably, the length of the rod-shaped structure is 10-1000 nm. Preferably, the golden needle mushroom structure has a large aspect ratio, and the aspect ratio is 1-50.
4. The method of producing a wave-absorbing material according to any one of claims 1 to 3, characterized by, The preparation method comprises the following steps: S1) dissolving a nickel source and a carbon source in a first part of a nitrogen-containing solvent to obtain an A solution; S2) dissolving an iron source in a second part of a nitrogen-containing solvent to obtain a B solution; S3) uniformly mixing the A solution and the B solution, adding an alkaline solution, and performing preheating treatment to obtain a mixed solution; S4) after the hydrothermal reaction of the mixed solution, cooling and collecting the precipitate; S5) after annealing treatment of the precipitate, the wave-absorbing material is obtained.
5. The production method according to claim 4, characterized by, The nickel source is selected from at least one of nickel acetate tetrahydrate, nickel chloride hexahydrate, and nickel nitrate hexahydrate. Preferably, the iron source is selected from potassium ferricyanide. Preferably, the carbon source is selected from at least one of polyvinylpyrrolidone, glucose, and sucrose. Preferably, the nitrogen-containing solvent is selected from N,N-dimethylformamide and propylene diamine.
6. The method of claim 4, wherein the step of forming the first and second layers is performed by a method comprising: In step S1, the molar ratio of the nickel source, the carbon source, and the first part of the nitrogen-containing solvent is 0.1-10:1-20:100-300. Preferably, in step S2, the molar ratio of potassium ferricyanide and the second part of the nitrogen-containing solvent is 0.1:10-50.
7. The method of claim 4, wherein the step of forming the first and second layers is performed by a method comprising: In step S3, the molar ratio of the nickel source, the carbon source, and the iron source is 1-10:1-100:1-10. Preferably, in step S3, the volume ratio of the mixed A solution and B solution to the volume of the alkaline solution is 1-20:
1. Preferably, in step S3, the preheating treatment is performed at 50-100℃ for 1-10h.
8. The method of claim 4, wherein the step of forming the first and second layers is performed by a method comprising: In step S4, the hydrothermal reaction is performed at 150-250℃ for 10-100h. Preferably, in step S4, the hydrothermal reaction is performed in a hydrothermal reaction kettle. Preferably, the precipitate obtained in step S4 comprises an FeNi precursor, and the surface of the FeNi precursor is loaded with the carbon source and the nitrogen-containing solvent.
9. The method of claim 4, wherein the step of forming the first and second layers is performed by a method comprising: In step S5, the annealing treatment is performed at 700-1000℃ in an Ar atmosphere for 2h, and the heating rate is 5℃ / min. Preferably, in step S5, during the annealing treatment, the FeNi precursor becomes FeNi alloy with a spherical structure, and the carbon source and nitrogen-containing solvent loaded on the surface of the FeNi precursor are converted into a nitrogen-doped carbon coating layer; the FeNi alloy acts as a catalyst to promote the carbon in the nitrogen-doped carbon coating layer to grow in a direction perpendicular to the contact surface between the FeNi alloy and the carbon coating layer to form a rod-like structure.
10. Use of the wave-absorbing material according to any one of claims 1-3 in electromagnetic functional materials.