Nitrogen and chlorine co-doped carbon wave-absorbing material based on nickel-manganese cooperation and preparation method and application thereof

Abstract

The invention discloses a nitrogen-chlorine co-doped carbon wave-absorbing material based on nickel-manganese cooperation and a preparation method and application thereof, and belongs to the technical field of electromagnetic wave absorbing materials. The material has a general formula (MnxNi1-x) N, Cl-C, where 0 lt; xlt; the preparation method comprises the following steps: 1, carrying out oxidative polymerization on a pyrrole monomer in an ethanol solution containing nickel salt, manganese salt and hydrochloric acid, and carrying out freeze drying and high-temperature pyrolysis. The method is simple in process, accurate and controllable doping of four elements of nickel, manganese, nitrogen and chlorine can be achieved, a multi-element synergistic loss mechanism is effectively constructed, and impedance matching and attenuation performance of the material is optimized. The prepared material shows an excellent broadband wave-absorbing characteristic in the frequency band of 2-18 GHz, especially when the matching thickness is 2.0-2.5 mm, the effective absorption bandwidth can reach 7.0 GHz, and the material is suitable for electromagnetic wave absorbents, electromagnetic shielding materials and related functional devices.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic wave absorbing materials technology, specifically relating to a nickel-manganese synergistic nitrogen-chlorine co-doped carbon absorbing material and its preparation method and application. Background Technology

[0002] With the rapid development of electronic information technology, electromagnetic waves are widely used in communication, detection, and everyday electronic devices, but this has also brought significant electromagnetic interference and radiation pollution problems. Developing high-performance electromagnetic wave absorbing materials has become an urgent need to ensure equipment compatibility, information security, and human health. Currently, absorbing materials are mainly divided into two categories: magnetic loss materials (such as ferrites) and dielectric loss materials (such as carbon-based materials).

[0003] Dielectric loss-type carbon-based materials (such as graphene and porous carbon) have attracted widespread attention due to their advantages such as light weight, stability, and ease of processing. However, their inherent high conductivity leads to a severe mismatch with air impedance, causing electromagnetic waves to be easily reflected at the surface and difficult to dissipate internally. This results in a narrow absorption bandwidth and insufficient absorption intensity, limiting their practical applications.

[0004] To improve performance, researchers typically employ doping modification strategies: one is to introduce non-metallic elements such as nitrogen and boron to enhance polarization loss by creating defects and functional groups; the other is to introduce magnetic metals such as iron, cobalt, and nickel to supplement loss pathways and enhance dielectric loss. However, single non-metal doping has limited effect on improving impedance matching, while single metal doping is prone to increasing material filling volume due to metal particle agglomeration. Neither approach can achieve lightweight, broadband, and strong absorption in the material.

[0005] Of particular note is that the controlled co-doping of multiple metals and non-metals to synergistically regulate dielectric properties and loss characteristics is an ideal approach to overcome existing bottlenecks. However, existing methods generally suffer from complex processes and uncontrollable element doping ratios and spatial distributions, making it difficult to accurately construct efficient multi-element synergistic loss systems, resulting in material performance failing to meet expectations. Therefore, developing a high-performance carbon-based microwave absorbing material with simple processing, controllable elements, and the ability to achieve synergistic effects of multiple loss mechanisms has significant research value and application prospects. Summary of the Invention

[0006] This invention provides a nickel-manganese synergistic nitrogen-chlorine co-doped carbon microwave absorbing material, its preparation method, and its application. The method involves simultaneously introducing nickel, manganese, nitrogen, and chlorine elements through pyrrole oxidative polymerization, followed by freeze-drying and programmed pyrolysis to obtain the material. It exhibits excellent broadband electromagnetic wave absorption performance and is suitable for microwave absorbing agents, shielding materials, and related devices.

[0007] On the one hand, the present invention provides a nitrogen-chlorine co-doped carbon microwave absorbing material based on nickel-manganese synergy, using the following technical solution: A nickel-manganese synergistic nitrogen-chlorine co-doped carbon microwave absorbing material, with the general chemical formula (Mn) x Ni 1-x )N,Cl-C, where 0 <x<1。

[0008] Preferably, x takes the value of 0.2, 0.4, 0.5, 0.6 or 0.8.

[0009] On the other hand, the present invention also provides a method for preparing a nitrogen-chlorine co-doped carbon microwave absorbing material based on nickel-manganese synergy, using the following technical solution: A method for preparing a nickel-manganese synergistic nitrogen-chlorine co-doped carbon microwave absorbing material includes the following steps: S1. Preparation of precursor solution: Dissolve pyrrole monomer, hydrochloric acid and metal salts containing nickel chloride and manganese chloride in ethanol, mix well to obtain solution A; S2. Preparation of oxidizing agent solution: Dissolve ferric chloride in deionized water to obtain solution B; S3. Synthesis of hydrogel: Solution A and solution B were rapidly mixed and subjected to oxidative polymerization reaction, and then placed in an ice-water bath for static aging to obtain polypyrrole hydrogel co-doped with bimetallic chloride and hydrochloric acid. S4. Post-treatment of hydrogel: The polypyrrole hydrogel obtained in step S3 is washed and freeze-dried to obtain a dry polypyrrole precursor. S5. High-temperature pyrolysis carbonization: Under the protection of an inert atmosphere, the dried polypyrrole precursor is subjected to high-temperature heat treatment to obtain a nitrogen-chlorine co-doped carbon microwave absorbing material based on nickel-manganese synergy.

[0010] Preferably, the total molar amount of nickel chloride and manganese chloride in the metal salt in step S1 is 7.2 mmol.

[0011] Preferably, the molar ratio of nickel chloride to manganese chloride in step S1 is (0.2-0.8):(0.8-0.2).

[0012] Preferably, the molar ratio of nickel chloride to manganese chloride is 0.2:0.8, 0.4:0.6, 0.5:0.5, 0.6:0.4, or 0.8:0.2.

[0013] Preferably, in step S1, the amount of pyrrole monomer used is 0.5 mL, the amount of hydrochloric acid used is 0.6 mL, and the volume of ethanol is 5 mL. In step S2, the mass of ferric chloride is 1.17 g and the volume of deionized water is 5 mL.

[0014] Preferably, the rapid mixing time in step S3 is 20 seconds, and the total time for oxidative polymerization and aging is 24 hours.

[0015] Preferably, the specific procedure for high-temperature heat treatment in step S5 is as follows: under an argon atmosphere, the temperature is increased to 800°C at a heating rate of 3°C / min, and then held at this temperature for 2 hours.

[0016] This invention also provides an application of a nickel-manganese synergistic nitrogen-chlorine co-doped carbon absorbing material in the preparation of electromagnetic wave absorbers, electromagnetic shielding materials, or related functional devices.

[0017] In summary, the beneficial effects of the present invention are as follows: This invention constructs a highly efficient multi-loss synergistic mechanism in a carbon matrix through precise co-doping of nickel and manganese bimetals with nitrogen and chlorine. This not only significantly enhances dielectric loss capability but, more importantly, achieves "bidirectional trimming" of the material's electromagnetic parameters, thereby optimizing impedance matching characteristics. This enables the material to exhibit excellent broadband absorption performance in the 2-18 GHz frequency band, while also enhancing the attenuation constant. In particular, with a matching thickness of 2.5 mm, its effective absorption bandwidth can reach up to 7.0 GHz, systematically solving the core problems of narrow absorption bandwidth and impedance mismatch in traditional carbon-based materials.

[0018] The integrated preparation process provided by this invention uses pyrrole polymerization as a reaction platform and simultaneously introduces all dopant sources, enabling precise control over the final material's chemical composition through simple steps. This method is simple, reproducible, and allows for elemental control, overcoming the bottleneck of complex existing multi-element doping processes. It provides a highly promising and reliable pathway for the large-scale preparation and practical application of high-performance, broadband, and lightweight microwave absorbing materials. Attached Figure Description

[0019] Figure 1 (Mn) prepared in Example 1 x Ni 1-x A schematic diagram of the synthesis process of N,Cl-C; Figure 2 In the middle, a refers to (Mn) prepared in Examples 1-5. x Ni 1-x X-ray diffraction pattern of N,Cl-C carbon materials; Figure 2 b is the (Mn) prepared in Examples 1-5. x Ni 1-x Raman spectra of N,Cl-C carbon materials; Figure 3 In Example 1, (Mn) is the a-value prepared by (Mn) 0.2 Ni 0.8 Scanning electron microscope images and particle size distribution diagrams of N,Cl-C carbon materials; Figure 3 b is the (Mn) prepared in Example 2. 0.4 Ni0.6 Scanning electron microscope images and particle size distribution diagrams of N,Cl-C carbon materials; Figure 3 c represents the (Mn) prepared in Example 3. 0.5 Ni 0.5 Scanning electron microscope images and particle size distribution diagrams of N,Cl-C carbon materials; Figure 3 d represents the (Mn) prepared in Example 4. 0.6 Ni 0.4 Scanning electron microscope images and particle size distribution diagrams of N,Cl-C carbon materials; Figure 3 In Example 5, (Mn) is the material prepared by e. 0.8 Ni 0.2 Scanning electron microscope images and particle size distribution diagrams of N,Cl-C carbon materials; Figure 3 f is the (Mn) prepared in Example 4. 0.6 Ni 0.4 Transmission and high-magnification transmission electron microscopy images of N,Cl-C carbon materials; Figure 4 In Example 1, (Mn) is the a-value prepared by (Mn) 0.2 Ni 0.8 Three-dimensional reflection loss diagram of N,Cl-C carbon materials; Figure 4 b is the (Mn) prepared in Example 2. 0.4 Ni 0.6 Three-dimensional reflection loss diagram of N,Cl-C carbon materials; Figure 4 c represents the (Mn) prepared in Example 3. 0.5 Ni 0.5 Three-dimensional reflection loss diagram of N,Cl-C carbon materials; Figure 4 d represents the (Mn) prepared in Example 4. 0.6 Ni 0.4 Three-dimensional reflection loss diagram of N,Cl-C carbon materials; Figure 4 In Example 5, (Mn) is the material prepared by e. 0.8 Ni 0.2 Three-dimensional reflection loss diagram of N,Cl-C carbon materials; Figure 4 f is the (Mn) prepared in Example 1. 0.2 Ni 0.8 Reflection loss curves of N,Cl-C carbon materials at different thicknesses; Figure 4 g is the (Mn) prepared in Example 2. 0.4 Ni 0.6Reflection loss curves of N,Cl-C carbon materials at different thicknesses; Figure 4 h is the (Mn) prepared in Example 3. 0.5 Ni 0.5 Reflection loss curves of N,Cl-C carbon materials at different thicknesses; Figure 4 In example i, (Mn) was prepared in Example 4. 0.6 Ni 0.4 Reflection loss curves of N,Cl-C carbon materials at different thicknesses; Figure 4 j is the (Mn) prepared in Example 5. 0.8 Ni 0.2 Reflection loss curves of N,Cl-C carbon materials at different thicknesses; Figure 5 In Figure a, the three-dimensional reflection loss diagram of the Mn,N,Cl-C carbon material prepared in Comparative Example 1 is shown. Figure 5 In Figure b, the three-dimensional reflection loss diagram of the Ni,N,Cl-C carbon material prepared in Comparative Example 2 is shown. Figure 5 In the figure, c represents the reflection loss curves of the Mn,N,Cl-C carbon material prepared in Comparative Example 1 at different thicknesses. Figure 5 In the figure, d represents the reflection loss curves of the Ni,N,Cl-C carbon material prepared in Comparative Example 2 at different thicknesses. Figure 6 In Example 1, (Mn) is the a-value prepared by (Mn) 0.2 Ni 0.8 Impedance matching diagram of N,Cl-C carbon materials; Figure 6 b is the (Mn) prepared in Example 2. 0.4 Ni 0.6 Impedance matching diagram of N,Cl-C carbon materials; Figure 6 c represents the (Mn) prepared in Example 3. 0.5 Ni 0.5 Impedance matching diagram of N,Cl-C carbon materials; Figure 6 d represents the (Mn) prepared in Example 4. 0.6 Ni 0.4 Impedance matching diagram of N,Cl-C carbon materials; Figure 6 In Example 5, (Mn) is the material prepared by e. 0.8 Ni 0.2 Impedance matching diagram of N,Cl-C carbon materials; Figure 6f is the (Mn) prepared in Examples 1-5. x Ni 1-x The attenuation constant diagram of N,Cl-C carbon materials.

[0020] Figure 7 In Figure a, the impedance matching diagram of the Mn,N,Cl-C carbon material prepared in Comparative Example 1 is shown. Figure 7 b is the impedance matching diagram of the Ni,N,Cl-C carbon material prepared in Comparative Example 2; Figure 7 In the figure, c represents the attenuation constant of the Mn,N,Cl-C and Ni,N,Cl-C carbon materials prepared in Comparative Examples 1-2. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the embodiments.

[0022] Example Example 1 A nickel-manganese synergistic nitrogen-chlorine co-doped carbon microwave absorbing material is prepared by the following method: S1. Add 0.5 mL of pyrrole monomer, 0.6 mL of hydrochloric acid, 1.44 mmol of MnCl2, and 5.76 mmol of NiCl2 to 5 mL of ethanol solution and mix thoroughly to obtain solution A. Dissolve 1.17 g of anhydrous FeCl3 in 5 mL of deionized water and label this solution B.

[0023] S2. Quickly mix solution A and solution B and stir for 20 seconds. Then transfer the mixture to an ice-water bath and allow it to stand at 0-5°C for oxidative polymerization for 24 hours to obtain a polypyrrole hydrogel co-doped with bimetallic chloride and hydrochloric acid.

[0024] S3. The obtained hydrogel was washed thoroughly with deionized water and ethanol alternately until the filtrate was neutral to remove unreacted monomers and impurities. The purified hydrogel was then freeze-dried to obtain the dried polypyrrole precursor.

[0025] S4. Place the dried polypyrrole precursor in a tube furnace and, under an argon atmosphere, program the temperature to 800°C at a heating rate of 3°C / min, then maintain this temperature at this rate for 2 hours for isothermal pyrolysis. After the furnace has cooled naturally to room temperature, the target product is obtained, denoted as (Mn). 0.2 Ni 0.8 ),N,Cl-C carbon materials.

[0026] like Figure 1 The image shown is a schematic diagram of the synthesis process.

[0027] Example 2 A nickel-manganese synergistic nitrogen-chlorine co-doped carbon microwave absorbing material is prepared using a method different from Example 1, except that the amount of MnCl2 in step S1 is changed from 1.44 mmol to 2.88 mmol, and the amount of NiCl2 is changed from 5.76 mmol to 4.32 mmol. The target product is denoted as (MnCl2). 0.4 Ni 0.6 The remaining preparation steps and process parameters are exactly the same as in Example 1.

[0028] Example 3 A nickel-manganese synergistic nitrogen-chlorine co-doped carbon microwave absorbing material is prepared using a method different from Example 1, except that the amount of MnCl2 in step S1 is changed from 1.44 mmol to 3.60 mmol, and the amount of NiCl2 is changed from 5.76 mmol to 3.60 mmol. The target product is denoted as (MnCl2). 0.5 Ni 0.5 The remaining preparation steps and process parameters are exactly the same as in Example 1.

[0029] Example 4 A nickel-manganese synergistic nitrogen-chlorine co-doped carbon microwave absorbing material is prepared using a method different from Example 1, except that the amount of MnCl2 in step S1 is changed from 1.44 mmol to 4.32 mmol, and the amount of NiCl2 is changed from 5.76 mmol to 2.88 mmol. The target product is denoted as (MnCl2). 0.6 Ni 0.4 The remaining preparation steps and process parameters are exactly the same as in Example 1.

[0030] Example 5 A nickel-manganese synergistic nitrogen-chlorine co-doped carbon microwave absorbing material is prepared using a method different from Example 1, except that the amount of MnCl2 in step S1 is changed from 1.44 mmol to 5.76 mmol, and the amount of NiCl2 is changed from 5.76 mmol to 1.44 mmol. The target product is denoted as (MnCl2). 0.8 Ni 0.2 The remaining preparation steps and process parameters are exactly the same as in Example 1.

[0031] Comparative Example Comparative Example 1 A manganese-nitrogen-chlorine co-doped carbon material is prepared in a manner different from that in Example 1, the amount of MnCl2 in step S1 is changed from 1.44 mmol to 7.2 mmol, and the amount of NiCl2 is changed from 5.76 mmol to 0 mmol. The target product is denoted as Mn,N,Cl-C carbon material. The remaining preparation steps and process parameters are exactly the same as in Example 1.

[0032] Comparative Example 2 A nickel-nitrogen-chlorine co-doped carbon material is prepared in a manner different from that in Example 1, the amount of MnCl2 in step S1 is changed from 1.44 mmol to 0 mmol, and the amount of NiCl2 is changed from 5.76 mmol to 7.2 mmol. The target product is denoted as Ni,N,Cl-C carbon material. The remaining preparation steps and process parameters are exactly the same as in Example 1.

[0033] Test case Test Example 1 Phase analysis was performed on the carbon material samples obtained in Examples 1-5. The specific steps are as follows: like Figure 2 As shown, the structure and doping state of the material were characterized by X-ray diffraction (XRD, Rigak, Cu Kα) and Raman spectroscopy (Raman, Renishaw): XRD showed a broad peak on the amorphous carbon (002) crystal plane at approximately 26°, and weak diffraction peaks belonging to nickel / manganese species appeared at specific positions, confirming that the metal element was introduced in the form of a crystalline phase; the Raman spectrum showed a distinct D peak (~1350 cm⁻¹). -1 ) and G peak (~1580 cm) -1 and higher I D / I G The intensity ratio indicates that nitrogen and chlorine doping and metal embedding introduce abundant defects and disordered structures into the carbon framework, providing a key structural basis for enhancing polarization relaxation loss.

[0034] Test Example 2 The carbon material samples obtained in Examples 1-5 were subjected to scanning electron microscopy, and the carbon material sample obtained in Example 4 was subjected to transmission electron microscopy and high-magnification transmission electron microscopy. The specific steps are as follows: The carbon material samples obtained in Examples 1-5 were observed under a scanning electron microscope (SEM, Hitachi, SU1000) and a high-power transmission electron microscope (TEM, JEOL-2100F).

[0035] like Figure 3 As shown, SEM displays (Mn x Ni 1-x The N,Cl-C material exhibits a uniform porous particle morphology with a narrow particle size distribution, and its morphology changes systematically with compositional control. TEM and high-resolution imaging further demonstrate that nanoscale nickel / manganese species are uniformly embedded in the amorphous carbon matrix, forming a tight interface, accompanied by carbon layer defects caused by nitrogen and chlorine doping. This uniform composite structure and abundant interfaces provide a key microscopic basis for enhancing interfacial polarization, optimizing the conductive network, and improving electromagnetic wave dissipation performance.

[0036] Test Example 3 The microwave absorption performance of the carbon material samples prepared in Examples 1-5 and Comparative Examples 1-2 of this invention was tested. The specific steps are as follows: 0.009 g of carbon material and 0.091 g of molten paraffin prepared in Examples 1-5 and Comparative Examples 1-2 were weighed respectively, and ultrasonically stirred at 80°C for 30 minutes to ensure thorough and uniform dispersion. The mixture was then poured into a specific mold and cooled to solidify, preparing a coaxial ring-shaped test sample with an outer diameter of 7.0 mm and an inner diameter of 3.0 mm. Using an Agilent PNA series vector network analyzer and a coaxial testing system, the electromagnetic parameters (real part of dielectric, imaginary part of dielectric) of the sample were measured in the frequency range of 2-18 GHz. and ) and the real and imaginary parts of permeability ( and The reflection loss (RL) is calculated based on transmission line theory, using the following formula: The impedance matching condition (Z) of an electromagnetic wave absorbing material can be calculated using the following formula: The attenuation constant (α) can be calculated using the following formula: in, and For the complex permittivity and complex permeability, For frequency, For sample thickness, The speed of light in a vacuum. and These are the input impedance and free space impedance, respectively. Attenuation coefficient ( This can be used to evaluate the combined contribution of magnetic and dielectric losses. Generally, the larger the attenuation constant, the greater the loss of electromagnetic waves. Each sample was measured three times to ensure data reliability.

[0037] like Figure 4 As shown, the different nickel-manganese ratios (Mn) prepared in Examples 1-5 are systematically illustrated using three-dimensional reflection loss maps and two-dimensional reflection loss curves. x Ni 1-x Electromagnetic wave absorption properties of N,Cl-C materials: All bimetallic doped samples exhibited superior broadband absorption characteristics compared to the single-metal comparative samples; among them, (Mn 0.6 Ni 0.4The N,Cl-C (Example 4) material exhibits the most outstanding performance, with a minimum reflection loss of -34.7 dB at a matching thickness of 2.0 mm and an effective absorption bandwidth of 5.5 GHz (12.5–18.0 GHz). When the thickness is increased to 2.5 mm, its effective absorption bandwidth can be further broadened to 7.0 GHz (11.0–18.0 GHz), fully covering the X-band and Ku-band. This fully demonstrates that the material can achieve excellent and tunable broadband absorption capabilities through the synergistic control of composition and thickness.

[0038] like Figure 5 As shown, the electromagnetic wave absorption performance of the single-metal doped comparative samples (Mn,N,Cl-C and Ni,N,Cl-C) in Comparative Examples 1-2 is demonstrated. The three-dimensional and reflection loss curves at different thicknesses show that, regardless of whether the material is doped with only manganese or only nickel, its minimum reflection loss value, effective absorption bandwidth and frequency band coverage are significantly lower than those of the nickel-manganese bimetallic co-doped samples in the embodiments of the present invention.

[0039] like Figure 6 As shown, different nickel-manganese ratios (Mn) are illustrated. x Ni 1-x Impedance matching characteristics (Figure ae) and attenuation constant (Figure f) of materials with proportions of N, Cl-C, x=0.2, 0.4, 0.5, 0.6, and 0.8 are shown. Impedance matching analysis indicates that all proportioned materials exhibit good impedance matching in the 2–18 GHz frequency band, with (Mn) showing particularly good impedance matching. 0.6 Ni 0.4 The N,Cl-C composition exhibits impedance matching closest to the ideal value (~1) over a relatively wide frequency band, indicating that this composition effectively promotes the penetration of electromagnetic waves into the material interior. The attenuation constant curves further demonstrate that all materials possess high attenuation capabilities, especially with a significant increase in the attenuation constant in the Ku band (12–18 GHz). Furthermore, the overall attenuation of the bimetallic doped system is superior to that of the single-metal control sample (e.g., ...). Figure 7 This result confirms from the perspective of electromagnetic parameters that the impedance matching and attenuation performance of the material can be synergistically optimized by adjusting the nickel-manganese ratio, thus providing a theoretical basis for achieving broadband strong absorption.

[0040] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A nitrogen-chlorine co-doped carbon microwave absorbing material based on nickel-manganese synergy, characterized in that, Its general chemical formula is (Mn x Ni 1-x )N,Cl-C, where 0 <x<1。 2. The nitrogen-chlorine co-doped carbon microwave absorbing material based on nickel-manganese synergy according to claim 1, characterized in that, The value of x is 0.2, 0.4, 0.5, 0.6 or 0.

8.

3. A method for preparing a nitrogen-chlorine co-doped carbon microwave absorbing material based on nickel-manganese synergy as described in claim 1 or 2, characterized in that, Includes the following steps: S1. Preparation of precursor solution: Dissolve pyrrole monomer, hydrochloric acid and metal salts containing nickel chloride and manganese chloride in ethanol, mix well to obtain solution A; S2. Preparation of oxidizing agent solution: Dissolve ferric chloride in deionized water to obtain solution B; S3. Synthesis of hydrogel: Solution A and solution B are rapidly mixed and subjected to oxidative polymerization reaction, and then placed in an ice-water bath for static aging to obtain a polypyrrole hydrogel co-doped with bimetallic chloride and hydrochloric acid. S4. Post-treatment of hydrogel: The polypyrrole hydrogel obtained in step S3 is washed and freeze-dried to obtain a dry polypyrrole precursor. S5. High-temperature pyrolysis carbonization: Under the protection of an inert atmosphere, the dried polypyrrole precursor is subjected to high-temperature heat treatment to obtain the nickel-manganese synergistic nitrogen-chlorine co-doped carbon microwave absorbing material.

4. The preparation method according to claim 3, characterized in that, In step S1, the total molar amount of nickel chloride and manganese chloride in the metal salt is 7.2 mmol.

5. The preparation method according to claim 3 or 4, characterized in that, In step S1, the molar ratio of nickel chloride to manganese chloride is (0.2-0.8):(0.8-0.2).

6. The preparation method according to claim 5, characterized in that, The molar ratio of nickel chloride to manganese chloride is 0.2:0.8, 0.4:0.6, 0.5:0.5, 0.6:0.4, or 0.8:0.

2.

7. The preparation method according to claim 3, characterized in that, In step S1, the amount of pyrrole monomer used is 0.5 mL, the amount of hydrochloric acid used is 0.6 mL, and the volume of ethanol is 5 mL; in step S2, the mass of ferric chloride is 1.17 g, and the volume of deionized water is 5 mL.

8. The preparation method according to claim 3, characterized in that, In step S3, the rapid mixing time is 20 seconds, and the total time for oxidative polymerization and aging is 24 hours.

9. The preparation method according to claim 3, characterized in that, In step S5, the specific procedure for the high-temperature heat treatment is as follows: under an argon atmosphere, the temperature is increased to 800°C at a heating rate of 3°C / min, and then held at this temperature for 2 hours.

10. The application of the nickel-manganese synergistic nitrogen-chlorine co-doped carbon absorbing material as described in claim 1 or 2 in the preparation of electromagnetic wave absorbers, electromagnetic shielding materials or related functional devices.

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