A composite wave absorbing material composed of nano nickel element and graphite carbon modified titanium carbide and a preparation method thereof

Abstract

The present invention relates to the field of nanocomposite materials, and in particular to a composite wave absorbing material composed of nano nickel and graphite carbon modified titanium carbide and a preparation method thereof. The preparation method firstly prepares a multilayer Ti3C2T x The monomers are then intercalated and layered using organic bases and ultrasonic oscillation, and ammonium ions are introduced to destroy the electrostatic balance to obtain a few-layer Ti3C2T x monomer; secondly, dopamine is used as a binder to fix Ni on Ti3C2T x On the sheet layer, Ni / PDA@Ti3C2T x Finally, after carbonization under argon, polydopamine was converted into carbon material, which is the composite material Ni / NC@Ti3C2T x The Ni / NC@Ti3C2T x Composite materials achieve broadband absorption of electromagnetic waves without increasing the density of the composite materials, comprehensively optimize the impedance matching characteristics of the materials, and lay a matching foundation for achieving broadband and strong absorption characteristics of electromagnetic waves.

Description

Technical Field

[0001] The invention relates to the field of micro-nano composite materials for electromagnetic wave absorption, and in particular to a composite wave absorbing material composed of nano nickel element and graphite carbon modified titanium carbide and a preparation method thereof. Background Art

[0002] The principle of radar detection is based on the emission of electromagnetic waves and the reception of effective echoes, thereby obtaining information such as the distance, position and height of the target. With the rapid development of modern radar detection technology and the diversification of military reconnaissance methods, stealth technologies such as marine ship equipment and weapons have been challenged greatly. As the core material of stealth technology, absorbing materials are high-tech technologies that are being developed by countries around the world today. Common absorbing materials can be divided into electrical loss type and magnetic loss type according to the loss mechanism. It is difficult for a single type of absorbing material to achieve good absorbing performance due to poor matching. In practical applications, electro-magnetic materials are usually used after being compounded to achieve excellent absorbing performance. However, the proportion of electro-magnetic components is not the more the better. Introducing too much electrical or magnetic materials will also lead to impedance mismatch, which is not conducive to practical applications.

[0003] Ti3C2T X MXene is a new type of two-dimensional ceramic material with a large specific surface area, abundant natural defects, abundant surface active groups and special metal characteristics. It has been widely used in the field of microwave absorption. X The non-magnetic properties, limited electromagnetic wave attenuation mechanism and overactive conductivity of MXene lead to unbalanced electromagnetic parameters, which cannot form a good impedance matching and limit its wave absorption performance. XIn order to solve the problems of impedance mismatch and single loss mechanism of MXene, researchers have explored methods to combine it with magnetic materials. For example, the preparation method of the composite absorber disclosed in the patent document with publication number CN 108251054A includes the following steps: (1) MXene powder is obtained by etching the MAX phase with hydrofluoric acid for 20 h and centrifuging, filtering and drying; (2) a sandwich structure MXene / Fe3O4 composite absorber is obtained by heating in a 50 mL reactor at a temperature of 200±5 ℃ and an ethylene glycol solvent system for 8 h; (3) the MXene / Fe3O4 composite absorber is heated at 300±5 ℃ for 1 h, i.e., annealing treatment, to obtain the final absorber. The maximum effective absorption bandwidth of the MXene / Fe3O4 composite absorber obtained by this method is 1.4 GHz. For example, the preparation method of MXene-based nanocomposite absorbing material disclosed in the patent document with publication number CN 114276781A includes the following steps: (1) etching MAX phase to obtain MXene; (2) mixing and pre-treating metal salt (one or more of organic salts and inorganic salts of iron, cobalt, and nickel) with the obtained MXene; (3) irradiating the pre-treated mixture; (4) finally post-treating to obtain the MXene-based nanocomposite absorbing material. The effective absorption bandwidth of the MXene-based nanocomposite absorbing material obtained by this method is 2.65 GHz.

[0004] However, the above patent introduces magnetic materials on the basis of MXene, which improves the magnetic loss in the composite system, but the serious self-stacking phenomenon of MXene itself and the limited loading capacity of magnetic particles have not been solved, and it is impossible to achieve broadband absorption at a thin thickness.

[0005] The present invention solves the above-mentioned problems and achieves the combination of excellent performances of multiple single-type materials, thus meeting the requirements of various industries for electromagnetic wave absorbing materials. Summary of the invention

[0006] In order to solve the problem mentioned in the background technology that although the introduction of magnetic materials on the basis of MXene can improve the magnetic loss in the composite system, MXene itself still has serious self-stacking phenomenon and limited magnetic particle loading, the present invention provides a method for preparing a composite microwave absorbing material composed of nano nickel element and graphite carbon modified titanium carbide, comprising the following steps:

[0007] Multilayer Ti3C2T x The monomers are intercalated and layered by organic base and ultrasonic vibration, and ammonium ions (NH4 + ) to destroy the electrostatic balance to form flocs, which are then collected and dried to obtain a few-layer Ti3C2T x monomer;

[0008] The few-layer Ti3C2T x The monomer powder was dispersed in deionized water, and dopamine hydrochloride was added and stirred. The suspension was centrifuged, the precipitate was washed and vacuum dried to obtain PDA@Ti3C2T x Composite material (Chinese name is polydopamine modified titanium carbide composite absorbing material);

[0009] The PDA@Ti3C2T x The composite material is dispersed evenly in the solvent, and then NiCl2·6H2O is added to disperse it, and then hydrazine hydrate and sodium hydroxide are added to stir evenly, and then reduction reaction is carried out at 160-200℃. After the reaction, the black-gray sample is collected, and then washed and vacuum dried in sequence to obtain Ni / PDA@Ti3C2T x The precursor is calcined at 600-700°C in an inert gas atmosphere to obtain the composite absorber composed of nano-nickel and graphite carbon modified titanium carbide, hereinafter referred to as Ni / NC@Ti3C2T x Composite materials.

[0010] In one embodiment, the solvent is ethylene glycol or anhydrous ethanol, but is not limited thereto.

[0011] In one embodiment, the multilayer Ti3C2T x The monomer was prepared by hydrofluoric acid etching of Ti3AlC2.

[0012] In one embodiment, the multilayer Ti3C2T x The monomer and the organic base aqueous solution are mixed according to the addition ratio of (0.5-1.5) g: (5-15) mL.

[0013] In one embodiment, in the multilayer Ti3C2T x The few-layer Ti3C2T obtained by intercalation and layering of monomers through organic base and ultrasonic vibration x In the solution, ammonia water and ammonium bicarbonate solution are added dropwise to destroy the electrostatic balance to form floccules.

[0014] It should be noted that the purpose of adding ammonia water and ammonium bicarbonate solution here is to introduce ammonium ions, and the ammonium ions are used to destroy the electrostatic balance. Here, the ammonium ions are added only when a sufficient amount is ensured until floccules are observed, so there is no need to specifically limit their content.

[0015] In one embodiment, the few-layer Ti3C2T x The mass ratio of the monomer powder to dopamine hydrochloride is 0.7-0.8:0.1-0.2.

[0016] In one embodiment, the PDA@Ti3C2T x Composite materials and Ni 2+ The mass ratio is 0.5-0.8: 0.05-0.8.

[0017] In one embodiment, the PDA@Ti3C2T x The addition ratio of the composite material, hydrazine hydrate and sodium hydroxide is (0.05-0.8) g: (0.024-0.4) mL: (0.068-1.12) g.

[0018] In one embodiment, the reaction time at 160-200° C. is 2-6 hours.

[0019] In one embodiment, the calcination process conditions are calcination at 600-700° C. with a heating rate of 2-8° C. / min for 1-3 h.

[0020] In one embodiment, the vacuum drying condition is drying at 60-80° C. for 12-24 hours.

[0021] The present invention also provides a composite wave absorbing material composed of nano nickel element and graphite carbon modified titanium carbide, which is prepared by any of the above-mentioned preparation methods.

[0022] Compared with the prior art, the present invention has the following technical principles and effects:

[0023] 1. The present invention solves the serious self-stacking phenomenon of MXene itself by coating a layer of polydopamine on the surface of MXene, and the abundant active groups on the coated polydopamine provide nucleation sites for the loading of magnetic particles, further solving the problem of limited magnetic loading.

[0024] 2. The precursor nickel / polydopamine / titanium carbide (Ti3C2T x ) can be converted into a low-density graphite carbon connecting medium after annealing, thereby achieving broadband absorption of electromagnetic waves without increasing the density of the composite material.

[0025] 3. The present invention introduces magnetic materials to precisely control the magnetic components, and this method has no effect on the electrical properties of the material, thereby comprehensively optimizing the impedance matching characteristics of the material and laying a matching foundation for achieving the material's broadband and strong absorption characteristics of electromagnetic waves. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0027] Figure 1 It is the scanning electron microscope image of each sample of the embodiment;

[0028] Figure 2 : is the reflection loss value of each sample in the embodiment at different thicknesses.

[0029] Figure 3 It is the reflection loss value of the comparative sample at different thicknesses. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The present invention provides an embodiment of a method for preparing a composite wave absorbing material composed of nano nickel and graphite carbon modified titanium carbide, and the specific operation steps are as follows:

[0032] S100, few-layer Ti3C2T X Powder preparation

[0033] Few-layer Ti3C2T x The preparation method of the powder is based on the method described in the reference (J Phys Chem Lett 11: 1247-1254), and the specific operation is as follows:

[0034] Multilayer Ti3C2T x The monomer and tetramethylammonium hydroxide (TMAOH) aqueous solution were mixed in an addition ratio of (0.5-1.5) g: (5-15) mL and stirred at room temperature for 18-24 h. The mixture was then centrifuged and washed once with deionized water. The collected precipitate was injected into deionized water and stirred vigorously to obtain a uniform multilayer Ti3C2T x Dispersion.

[0035] The obtained multilayer Ti3C2T xThe dispersion was ultrasonically treated for 25-35 min and then centrifuged at 3000-4000 rpm, and the supernatant was collected for use in subsequent experimental steps.

[0036] The precipitate after centrifugation was dispersed again in deionized water, and the above-mentioned ultrasonic treatment and centrifugation operation were repeated until the total ultrasonic stratification time reached 2.5-3.5h.

[0037] All the above supernatants were collected together to obtain the few-layer Ti3C2T x solution, in few-layer Ti3C2T x Add 5-15 mL of 28% ammonia water to the solution, then drop 1.8-3.0 g of ammonium bicarbonate solution. As flocs form, let stand for a while or centrifuge at low speed, and dry at 60-80 ° C for 12-24 h to obtain a few-layer Ti3C2T x powder.

[0038] The above multilayer Ti3C2T x The monomer is prepared by HF acid etching. Those skilled in the art may refer to the literature (Advanced Materials, 2011, 23(37): 4207-4207). Specifically, the multilayer Ti3C2T x The monomer preparation method is as follows:

[0039] Under the stirring of the polyvinylidene fluoride magnetic bar, 0.5-0.8 g of Ti3AlC2 powder was gradually added into 10-16 mL40 w t.% HF (addition completed within 5-10 min), and then magnetically stirred for 12-48 h at room temperature (23 °C). After stirring, the powder was centrifuged (3500 rpm / min, 5-10 min per cycle) and washed separately. The specific washing process is as follows:

[0040] After each centrifugation cycle, Ti3C2T x The sediment settles at the bottom of the centrifuge tube, separating the precipitate from the aqueous supernatant;

[0041] Pour the acidic liquid after each cycle of washing into the waste, and then wash the Ti3C2T x The precipitate is re-ultrasonic dispersed and then centrifuged repeatedly. The washing is repeated until the pH value of the supernatant is 6. The precipitate obtained after washing is dried at 60-80°C for 12-24h to obtain multilayer Ti3C2T x .

[0042] It should be noted that the reason why Ti3AlC2 powder is added gradually in the above operation is to reduce excessive bubbles formed due to the exothermic nature of the reaction.

[0043] S200, PDA@Ti3C2T x Preparation of composite materials

[0044] The few-layer Ti3C2T x The powder was dispersed in deionized water and ultrasonically dispersed for 15-25 min, then dopamine hydrochloride was added and stirred vigorously for 18-24 h. x The mass ratio of PDA@Ti3C2T to dopamine hydrochloride is 0.7-0.8:0.1-0.2. After stirring, the suspension is centrifuged, the precipitate is washed with deionized water and ethanol, and then dried under vacuum conditions at 60-80°C for 12-24h to obtain PDA@Ti3C2T x Composite materials.

[0045] S300, Ni / NC@Ti3C2T x Preparation of composite materials

[0046] Preparation of Ni / NC@Ti3C2T by solvothermal method and annealing treatment x :Weigh PDA@Ti3C2T x Dispersed in anhydrous ethanol, ultrasonically dispersed for 5-15min, and then NiCl2·6H2O was added to the above solution (where PDA@Ti3C2T x with Ni 2+ The mass ratio is 05-0.8: 0.05-0.8), and then ultrasonically dispersed for 10-20 minutes after stirring at room temperature for 5-10 minutes. Then pour hydrazine hydrate and sodium hydroxide into the liquid mixture and stir for 5-10 minutes. After stirring, put the mixture into a stainless steel autoclave and keep it at 160-200°C for 2-6 hours. After the reaction is completed, collect the black-gray sample, first centrifuge it with water until the supernatant is clear, then centrifuge it with ethanol for about 2 times (centrifugation conditions are about 8000 rpm / min), and dry it at 60-80°C vacuum conditions for 12-24 hours to obtain Ni / PDA@Ti3C2T x The precursor is calcined at 600-700℃ in an inert gas atmosphere at a heating rate of 2-8℃ / min for 1-3h to obtain Ni / NC@Ti3C2T x Composite materials.

[0047] The present invention also provides the following embodiments

[0048] Example 1

[0049] (1) Few-layer Ti3C2TX Powder preparation

[0050] 1 g of the prepared multilayer Ti3C2T x The precipitate was dispersed in 10 ml of 25% tetramethylammonium hydroxide (TMAOH) aqueous solution and stirred at room temperature for 24 h. It was then washed once with deionized water by centrifugation. The collected precipitate was injected into 50 ml of deionized water and stirred vigorously to obtain a uniform multilayer Ti3C2T x Dispersion in aqueous solution. Ultrasonic TMAOH treated multilayer Ti3C2T x Dispersion aqueous solution, centrifuged after 30 min. Collect the supernatant after centrifugation for subsequent experimental steps, and disperse the precipitate after centrifugation in 50 ml deionized water again. Repeat the above steps until the total ultrasonic stratification time reaches 3h. Collect all the above supernatants together to collect about 300 ml of few-layer Ti3C2T x Nanosheet dispersion. In 300 ml of few-layer Ti3C2T x 7.5 ml of 28% ammonia water was added to the solution, and then ammonium bicarbonate solution (prepared by dissolving 2.4 g of ammonium bicarbonate in 30 ml of deionized water) was added dropwise. As flocs formed, the mixture was allowed to stand for a period of time or centrifuged at low speed, and dried at 60 °C for 24 h to obtain a few-layer Ti3C2T x powder.

[0051] (2) PDA@Ti3C2T x Preparation

[0052] 0.8 g of the few-layer Ti3C2T prepared in the above steps was x The powder was dispersed in 200 mL of deionized water and ultrasonically dispersed for 20 minutes. Then 0.2 g of dopamine hydrochloride was added and stirred vigorously for 24 h. After stirring, the suspension was centrifuged, washed with deionized water and ethanol, and dried at 60 °C in vacuum for 24 h to obtain PDA@Ti3C2T x Composite materials.

[0053] (3) Ni / NC@Ti3C2T x Preparation of -1

[0054] Preparation of Ni / NC@Ti3C2T by solvothermal method and annealing treatment x :Weigh 0.6g PDA@Ti3C2T x Dispersed in 60 mL of anhydrous ethanol, ultrasonically dispersed for 10 min, and then weighed NiCl2·6H2O (Ni 2+ / PDA@Ti3C2T xAdd 10 mL of 50% hydrazine hydrate and 0.4 g of sodium hydroxide into the liquid mixture and stir for 5 min. After stirring, put the mixture into a stainless steel autoclave and keep it at 180 ° C for 2 h. After the reaction, collect the black-gray sample, wash it with water by centrifugation until the supernatant is clear and not turbid, and then wash it with ethanol by centrifugation for about 2 times (the centrifugation condition is about 8000 rpm / min), and dry it at 70 ° C under vacuum for 20 h to obtain Ni / PDA@Ti3C2T x Finally, the precursor was calcined at 700 °C in N2 atmosphere for 2 h with a heating rate of 5 °C / min to obtain Ni / NC@Ti3C2T x -1 Composite material.

[0055] Example 2

[0056] Steps (1) and (2) of Example 2 are exactly the same as those of Example 1, except for step (3).

[0057] (3) Ni / NC@Ti3C2T x Preparation of -2

[0058] Preparation of Ni / NC@Ti3C2T by solvothermal method and annealing treatment x :Weigh 0.6g PDA@Ti3C2T x Dispersed in 60 mL of anhydrous ethanol, ultrasonically dispersed for 10 min, and then weighed NiCl2·6H2O (Ni 2+ / PDA@Ti3C2T x Add 10 mL of 50% hydrazine hydrate and 0.4 g of sodium hydroxide into the liquid mixture and stir for 5 min. After stirring, put the mixture into a stainless steel autoclave and keep it at 180 ° C for 2 h. After the reaction, collect the black-gray sample, wash it with water by centrifugation until the supernatant is clear and not turbid, and then wash it with ethanol by centrifugation for about 2 times (the centrifugation condition is about 8000 rpm / min), and dry it at 70 ° C under vacuum for 20 h to obtain Ni / PDA@Ti3C2T x Finally, the precursor was calcined at 700 °C in N2 atmosphere for 2 h with a heating rate of 5 °C / min to obtain Ni / NC@Ti3C2T x -2 Composite materials.

[0059] Example 3

[0060] Steps (1) and (2) of Example 3 are exactly the same as those of Example 1, except for step (3);

[0061] (3) Ni / NC@Ti3C2T x Preparation of -3

[0062] Preparation of Ni / NC@Ti3C2T by solvothermal method and annealing treatment x :Weigh 0.6g PDA@Ti3C2T x Dispersed in 60 mL of anhydrous ethanol, ultrasonically dispersed for 10 min, and then weighed NiCl2·6H2O (Ni 2+ / PDA@Ti3C2T x Add 100 mL of 50% hydrazine hydrate and 0.4 g of sodium hydroxide into the liquid mixture and stir for 5 min. After stirring, put the mixture into a stainless steel autoclave and keep it at 180 ° C for 2 h. After the reaction, collect the black-gray sample, wash it with water and ethanol several times, wash it with water by centrifugation until the supernatant is clear and not turbid, and then wash it with ethanol by centrifugation for about 2 times (the centrifugal condition is about 8000 rpm / min), and dry it at 70 ° C under vacuum for 20 h to obtain Ni / PDA@Ti3C2T x Finally, the precursor was calcined at 700 °C in N2 atmosphere for 2 h with a heating rate of 5 °C / min to obtain Ni / NC@Ti3C2T x -3 Composite materials.

[0063] Comparative Example

[0064] The present invention also provides the existing CoFe@Ti3C2T x The composite material is used as a comparative example, and its preparation method is as follows:

[0065] Ti3C2T x The powder was prepared by removing the Al layer from Ti3AlC2: 1.0 g Ti3AlC2 was added to 10 mL hydrofluoric acid aqueous solution and stirred for 65 h. After that, the suspension was centrifuged and washed with deionized water to pH = 7 to obtain a precipitate that was then freeze-dried.

[0066] Further improvement of Ti3C2T by one-step solvothermal method x Interlayer space of MXene: 0.5 g of Ti3C2T etched by hydrofluoric acid was placed x Dispersed into 40 mL DMF, the suspension was then deoxygenated with N2 for 30 min, further sonicated for 2 h, and deoxygenated again for 30 min.

[0067] Next, the dispersion was introduced into a 50 mL polytetrafluoroethylene-lined autoclave and sealed at 120 °C for 4 h. The prepared precipitate was centrifuged and washed with deionized water and ethanol several times to obtain a black powder, which was then dried in a freezer to obtain the product D-Ti3C2T x MXene.

[0068] Finally, CoFe@Ti3C2T x The composite material was synthesized by in-situ reduction method in an oil bath: 0.5 g D-Ti3C2T x MXene was redispersed in 200 mL of degassed water, and then 0.215 mmol of CoCl2·6H2O and FeSO4·7H2O were dissolved in the above solution under N2 atmosphere. x The suspension was ultrasonically treated for 24 h. Next, the suspension was transferred to a 250 mL three-necked flask, 9.88 g NaOH and 40 mL N2H4·H2O were added, and the reaction was carried out in an oil bath at 66 °C for 1 h. After the reaction, the oil bath was removed and the flask was continuously purged with N2 until the suspension cooled to ambient temperature. After centrifugation and rinsing with ultrapure water and ethanol several times, CoFe@Ti3C2T was obtained by freeze drying. x Composite materials.

[0069] The products obtained in the above embodiments and comparative examples were subjected to performance tests (using a Keysight N5222B vector network analyzer, with a test frequency of 2-18 GHz, and tested according to the coaxial ring method). The test results are shown in Table 1 and Figure 1 , Figure 2 As shown:

[0070] Table 1 Example test results

[0071] absorbers Thickness(mm) max RL (dB)(corresponding frequency GHz) Maximum reflection loss value; (the frequency at which the maximum reflection loss value occurs) Frequency range (RL<-10dB) (effective absorption frequency range) EAB(GHz)(Effective Absorption Bandwidth) Example 1 2.0 -28.43(12.22) 14.19-10.49 3.70 Example 2 1.5 -20.60(15.20) 13.20-17.85 4.65 Example 3 2.0 -23.23(11.34) 9.75-14.07 4.32 Comparative Example 1.7 -35.00（11.00） 10.40-12.80，17.40-18.00 3.00

[0072] in, Figure 1 The figures are the microscopic morphologies of the samples in the embodiments at different magnifications. Specifically, part a and part b correspond to the samples prepared in embodiment 2, part a is the scanning electron microscope image at low magnification, and part b is the scanning electron microscope image at high magnification; part c corresponds to the scanning electron microscope image of the sample prepared in embodiment 1 at high magnification; part d corresponds to the scanning electron microscope image of the sample prepared in embodiment 3 at high magnification.

[0073] Figure 2The graphs in part a are the reflection loss values ​​of the samples in the examples at different thicknesses. Specifically, the graph in part b reflects the reflection loss values ​​of the samples in the examples 1 at different thicknesses; the graph in part c reflects the reflection loss values ​​of the samples in the examples 2 at different thicknesses.

[0074] From Table 1 and Figure 2 It can be seen from the test results that Ni / NC@Ti3C2T x The minimum reflection loss of the -3 sample is -23.23 dB at a frequency of 11.34 GHz and a thickness of 2 mm, and the effective absorption bandwidth is 4.32 GHz. x -2 sample has a minimum reflection loss of -20.60 dB and an effective absorption bandwidth of 4.65 GHz at a frequency of 15.20 GHz and a thickness of 1.5 mm. x The minimum reflection loss of the -1 sample at a frequency of 12.22 GHz and a thickness of 2 mm reaches -28.43 dB, and the effective absorption bandwidth is 3.70 GHz. The minimum reflection loss of the comparative sample at a thickness of 1.7 mm is -35.00 dB, and the effective absorption bandwidth is 3.00 GHz. After a comprehensive comparison of the performance of each sample, it can be seen that the absorbing performance of the sample of the embodiment is better than that of the comparative sample, especially Ni / NC@Ti3C2T x -2 achieves broadband and strong absorption of electromagnetic waves in thin thickness.

[0075] from Figure 1 It can be seen from the high magnification figure in the figure that the composite materials prepared in these embodiments are all sheet structures with a diameter of about 1um. By reducing the magnification to observe the overall microscopic morphology of the composite materials (refer to Figure 1 (a) It is found that the layered Ni / NC@Ti3C2T x They are evenly and alternately combined together to form a flocculent structure with good dispersion.

[0076] Figure 3 is the reflection loss value of the sample in the comparative example at different thicknesses. From the test results of the comparative example and the embodiment, it can be seen that the comparative example is directly x The product CoFe@Ti3C2T was obtained by in-situ growth of FeCo alloy x The measured effective absorption bandwidth is 3.0 GHz. Obviously, the embodiment has a more excellent wave absorbing performance.

[0077] In addition, the difference between the above embodiments is only that Ni 2+ The addition ratio is different, from Table 1 and Figure 2It can also be seen that the prepared Ni / NC@Ti3C2T x -1 The wave absorption properties of composite materials are different. Therefore, the magnetic components can be precisely controlled by introducing magnetic materials, thereby comprehensively optimizing the impedance matching characteristics of the material.

[0078] In summary, the composite absorbing material composed of nano nickel element and graphite carbon modified titanium carbide prepared by the preparation method of the present invention achieves broadband and strong absorption of electromagnetic waves at a thin thickness and has excellent absorbing performance.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 a composite wave absorbing material composed of nano nickel and graphite carbon modified titanium carbide, characterized in that: The steps include: Multilayer Ti3C2T x The monomers are intercalated and layered by organic base and ultrasonic vibration, and ammonium ions are introduced to destroy the electrostatic balance to form floccules. After standing or centrifugation, the precipitate is collected and dried to obtain a few-layer Ti3C2T x monomer; The few-layer Ti3C2T x The monomer powder was dispersed in deionized water, and dopamine hydrochloride was added and stirred. The suspension was centrifuged, the precipitate was washed and vacuum dried to obtain PDA@Ti3C2T x Composite materials; The PDA@Ti3C2T x The composite material is dispersed evenly in the solvent, and then NiCl2·6H2O is added to disperse it, and then hydrazine hydrate and sodium hydroxide are added to stir evenly, and then reacted at 160-200℃. After the reaction is completed, a black-gray sample is collected, and then washed and vacuum dried in sequence to obtain Ni / PDA@Ti3C2T x Precursor, and calcining the precursor in an inert gas atmosphere at 600-700°C to obtain the composite microwave absorbing material composed of nano nickel element and graphite carbon modified titanium carbide; The solvent is ethylene glycol or anhydrous ethanol; The PDA@Ti3C2T x Composite materials and Ni 2+ The mass ratio is 0.5-0.8: 0.05-0.

8.

2. The method for preparing the composite microwave absorbing material composed of nano nickel and graphite carbon modified titanium carbide according to claim 1, characterized in that: The multilayer Ti3C2T x The monomer was prepared by hydrofluoric acid etching of Ti3AlC2.

3. The method for preparing the composite microwave absorbing material composed of nano nickel element and graphite carbon modified titanium carbide according to claim 1, characterized in that: The multilayer Ti3C2T x The monomer and the organic base aqueous solution are mixed according to the addition ratio of (0.5-1.5) g: (5-15) mL.

4. The method for preparing the composite microwave absorbing material composed of nano nickel element and graphite carbon modified titanium carbide according to claim 1, characterized in that: In the multilayer Ti3C2T x The few-layer Ti3C2T obtained by intercalation and layering of monomers through organic base and ultrasonic vibration x In the solution, ammonia water and ammonium bicarbonate solution are added dropwise to destroy the electrostatic balance to form floccules.

5. The method for preparing the composite microwave absorbing material composed of nano nickel element and graphite carbon modified titanium carbide according to claim 1, characterized in that: The few-layer Ti3C2T x The mass ratio of the monomer powder to dopamine hydrochloride is 0.7-0.8:0.1-0.

2.

6. The method for preparing the composite microwave absorbing material composed of nano nickel element and graphite carbon modified titanium carbide according to claim 1, characterized in that: The PDA@Ti3C2T x The addition ratio of the composite material, hydrazine hydrate and sodium hydroxide is (0.05-0.8) g: (0.024-0.4) mL: (0.068-1.12) g.

7. The method for preparing the composite microwave absorbing material composed of nano nickel element and graphite carbon modified titanium carbide according to claim 1, characterized in that: The calcination process conditions are calcination at 600-700° C. with a heating rate of 2-8° C. / min for 1-3 hours.

8. A method for preparing a composite microwave absorbing material composed of nano nickel and graphite carbon modified titanium carbide, characterized in that: Prepared by the preparation method according to any one of claims 1 to 7.

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