Efficient composite wave-absorbing material NiCo-C-PANI and preparation method thereof

Abstract

The invention discloses an efficient composite wave-absorbing material NiCo-C-PANI and a preparation method thereof, and belongs to the technical field of composite materials. The preparation method comprises the following steps: firstly, preparing NiCo-BTC by adopting a solvothermal method, dispersing the NiCo-BTC, and adding tris (hydroxymethyl) aminomethane and dopamine hydrochloride to obtain NiCo (at) PDA; secondly, carrying out high-temperature calcination on the NiCo-coated PDA to obtain NiCo-coated C; and finally, dispersing NiCo-C, adding hydrochloric acid, an aniline monomer and ammonium persulfate to obtain a mixed solution, and reacting to obtain a product. According to the preparation method disclosed by the invention, polydopamine is sequentially introduced to the surface of NiCo-BTC and is calcined to obtain a carbon-coated nickel-cobalt alloy composite material, and a layer of polyaniline is attached to the outer layer of the carbon-coated nickel-cobalt alloy composite material; due to the synergistic effect of interface polarization generated among all levels of the core-shell structure, dielectric loss of the carbon layer and polyaniline and magnetic loss of the core alloy, the material has good impedance matching performance and attenuation capacity; electromagnetic parameters of the composite material are regulated and controlled by adjusting the proportion of nickel and cobalt metal particles and changing the proportion of nickel and cobalt metal to carbon and polyaniline dielectric components, and the wave absorbing performance is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials, and relates to a high-efficiency composite microwave absorption material NiCo@C@PANI derived from nickel-cobalt bimetallic organic framework and a preparation method thereof. Background Art

[0002] Electronic information technology is developing at an astonishing speed, and the types of civilian and military electronic information devices have increased sharply, bringing rich electromagnetic pollution. Electromagnetic pollution will interfere with the normal operation of other electronic devices and even endanger human health. To solve this problem, the design and manufacture of microwave absorbers have become a very important topic in modern society.

[0003] As a typical microwave absorption material, magnetic and dielectric materials need to meet the characteristics of rich resources, low cost, easy preparation, light weight, low relative density, high efficiency, frequency range response, etc. However, traditional metal magnetic particles and their compound microwave absorption materials have large density and poor corrosion resistance, which affect their practical applications. At present, the research on the preparation of multifunctional microwave absorption materials by multi-component composite of metal-organic frameworks and carbon materials has received extensive attention.

[0004] The NiCo@C@PANI prepared by the present invention by introducing a carbon material with low density and high chemical stability into the metal-organic framework and attaching a layer of conductive polyaniline on the outermost layer has excellent microwave absorption performance. The preparation method has simple process, is green and environmentally friendly, has universality, and is suitable for large-scale industrial production. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the present invention provides a simple method for preparing a composite microwave absorption material NiCo@C@PANI derived from nickel-cobalt bimetallic organic framework and a preparation method thereof. The present invention first synthesizes nickel-cobalt bimetallic MOF (NiCo-BTC) by solvothermal method. After it is fully dried, polydopamine is introduced onto its surface and then calcined to obtain a carbon-coated nickel-cobalt alloy composite material. Then, a layer of polyaniline with a certain crystallinity is attached to its outer layer. The interfacial polarization generated between the core-shell structures at all levels and the synergistic effect of the dielectric loss of the carbon layer and polyaniline and the magnetic loss of the inner core alloy make the material have good impedance matching and attenuation ability. Therefore, the prepared composite microwave absorption material NiCo@C@PANI has excellent microwave absorption performance.

[0006] To achieve the above purpose, the preparation method adopted by the present invention is:

[0007] A preparation method of an efficient electromagnetic wave absorbing composite material NiCo@C@PANI. The preparation method realizes the regulation of the electromagnetic parameters of the composite material and improves the wave absorption performance by adjusting the ratio of two metal particles of nickel and cobalt and changing the ratio of nickel-cobalt metal to dielectric components of carbon and polyaniline. The method comprises the following steps:

[0008] Step 1) Prepare nickel-cobalt bimetallic MOF (NiCo-BTC) by a solvothermal method. The obtained NiCo-BTC is in powder form and serves as intermediate 1. Poly dopamine is successively introduced onto its surface and then calcined to obtain a carbon-coated nickel-cobalt alloy composite material.

[0009] Step 2) After completely drying intermediate 1, it is fully dispersed in deionized water. Then, tris(hydroxymethyl)aminomethane and dopamine hydrochloride are added, and the mixture is stirred thoroughly, centrifuged, filtered by suction, washed, and dried to obtain NiCo@PDA powder, which serves as intermediate 2.

[0010] Step 3) Intermediate 2 is subjected to high-temperature calcination treatment to obtain NiCo@C, which serves as intermediate 3.

[0011] Step 4) Intermediate 3 (i.e., NiCo@C) is fully dispersed in deionized water. Hydrochloric acid, aniline monomer, and ammonium persulfate are added to obtain a mixed solution, and the mixed solution is reacted at 0 - 5 °C for 24 h. After centrifugation, suction filtration, washing, and drying, the final product NiCo@C@PANI is obtained.

[0012] Further, in step 1), the intermediate 1 is prepared by a solvothermal method, specifically: cobalt nitrate hexahydrate (Co(NO 3 )) 2 ·6H 2 O), nickel nitrate hexahydrate (Ni(NO 3 )) 2 ·6H 2 O), polyvinylpyrrolidone (PVPK30), and trimesic acid (BTC) are fully dissolved in an organic solvent. Among them, the molar ratio of cobalt nitrate hexahydrate (Co(NO 3 )) 2 ·6H 2 O) to nickel nitrate hexahydrate (Ni(NO 3 )) 2 ·6H 2 O) is 1:2 - 2:1, and the mass ratio of PVP to BTC is 5:1, denoted as solution 1. After stirring thoroughly for 20 - 40 min, it is poured into the inner liner of an 80 mL polytetrafluoroethylene reaction kettle, the reaction kettle is tightened, and solvent heat treatment is carried out at 120 - 180 °C for 4 - 8 h. After centrifugation, washing with water, washing with alcohol, and drying, intermediate 1 is obtained.

[0013] Further, in step 1), the organic solvent includes N,N-dimethylformamide (DMF) and methanol.

[0014] Further, in solution 1 of step 1), the concentration of Co(NO 3 ) 2 ·6H 2 O is 0.033 - 0.066 mol / L, and the concentration of Ni(NO 3 ) 2 ·6H 2 O is 0.033 - 0.066 mol / L;

[0015] Further, in step 2), the mass ratio of intermediate 1, tris(hydroxymethyl)aminomethane, and dopamine hydrochloride is 12:5:12.

[0016] Further, in step 3), the NiCo@PDA powder is calcined in a tubular furnace at 650 - 850 °C for 1 - 3 h in an argon atmosphere.

[0017] Further, in step 4), the mass ratio of NiCo@C to aniline monomer is controlled at 1:0.75 - 3, and the optimal ratio is 1:2.

[0018] Further, in step 4), for every 50 ml of deionized water, 0.25 g of NiCo@C is added. In the mixed solution formed by 50 ml of deionized water, the hydrochloric acid concentration is 0.5 moL / L, the molar ratio of ammonium persulfate to aniline monomer is 1:1, and the addition amount of aniline monomer is 0.2 - 0.75 mL.

[0019] A high - efficiency microwave - absorbing composite material NiCo@C@PANI is prepared by the above - mentioned preparation method.

[0020] The beneficial effects of the present invention are as follows:

[0021] When the matching thickness of NiCo@C@PANI is only 1.9 mm, the best reflection loss can reach - 62.10 dB, and it has an effective absorption bandwidth of 5.87 GHz at this matching thickness. The interfacial polarization generated between the levels of the core - shell structure, as well as the synergistic effect of the dielectric loss of the carbon layer and polyaniline and the magnetic loss of the inner - core alloy, endow the material with good impedance matching and attenuation ability. Therefore, the prepared composite microwave - absorbing material NiCo@C@PANI has excellent microwave absorption performance.

[0022] From the synthesis process, using NiCo - BTC as a template and dopamine hydrochloride as a carbon source, after high - temperature calcination, the protonic acid doping method is adopted. The aniline monomer polymerizes in a hydrochloric acid solution containing ammonium persulfate to introduce the dielectric layer of polyaniline, and a core - shell microwave - absorbing material NiCo@C@PANI is prepared by coating a carbon layer and a polyaniline layer on the surface of the NiCo alloy. Description of the Drawings

[0023] Figure 1 XRD pattern of NiCo@C@PANI obtained in Example 3;

[0024] Figure 2 SEM image of NiCo@C@PANI obtained in Example 3; Figure 2 (a) SEM image of NiCo@C@PANI at low magnification; Figure 2 (b) SEM image of NiCo@C@PANI at high magnification;

[0025] Figure 3 TEM image of NiCo@C@PANI obtained in Example 3; Figure 3 (a) TEM image of NiCo@C@PANI at low magnification; Figure 3 (b) TEM image of NiCo@C@PANI at high magnification;

[0026] Figure 4 Raman spectrum of NiCo@C@PANI obtained in Example 3;

[0027] Figure 5 Wave absorption performance diagram of NiCo@C@PANI obtained in Example 3. Detailed implementation manners

[0028] The present invention will be further described below in conjunction with specific embodiments.

[0029] Using NiCo-BTC as a template and dopamine hydrochloride as a carbon source, after high-temperature calcination, the protonic acid doping method is adopted. Aniline monomers are polymerized in a hydrochloric acid solution containing ammonium persulfate to introduce the dielectric layer of polyaniline, and a core-shell microwave absorption material NiCo@C@PANI is prepared by coating a carbon layer and a polyaniline layer on the surface of the NiCo alloy. In the X-ray diffraction pattern (attached Figure 1 ), three diffraction peaks appear at about 2θ = 15°, 20°, and 25°, which proves that polyaniline has a certain degree of crystallinity under protonic acid doping. From the SEM image (attached Figure 2 ), it can be observed that NiCo@C@PANI has a "durian-like" structure, and the outer fibrous matter is conductive polyaniline. From the TEM image (attached Figure 3 ), a spherical structure wrapped by fibrous matter can also be observed. The above shows that the NiCo@C@PANI is successfully prepared by this method. The preliminary test of the network vector analyzer and the later simulation with MATLAB (attached Figure 5 ) can both well prove that NiCo@C@PANI has good wave absorption performance, indicating the feasibility of this method.

[0030] The present invention will be further described below in conjunction with specific embodiments.

[0031] Example 1 Preparation method of an efficient composite wave-absorbing material NiCo@C@PANI-1 (1) Preparation of NiCo-BTC;

[0032] Dissolve 0.87 g of Co(NO 3 ) 2 ·6H 2 O, 0.87 g of Ni(NO 3 ) 2 ·6H 2 O, 3.0 g of PVP (K30), and 0.6 g of BTC in 60 mL of methanol solvent, ultrasonically stir for 40 min, and record it as solution A. Transfer solution A to the inner liner of an 80 mL polytetrafluoroethylene-lined autoclave, tighten the autoclave, and perform solvent heat treatment at 120 °C for 8 h. Wash successively with methanol, deionized water, and absolute ethanol, and dry to obtain the intermediate NiCo-BTC.

[0033] (2) Preparation of NiCo@PDA;

[0034] Fully dissolve 0.2850 g of NiCo-BTC in 100 mL of deionized water containing 0.121 g of Tris. After ultrasonically stirring for 30 min, add 0.2850 g of dopamine hydrochloride (DA), and the powder product obtained after stirring for 24 h is NiCo@PDA.

[0035] (3) Preparation of NiCo@C;

[0036] Calcine the NiCo@PDA powder in a tubular furnace under an argon atmosphere at 650 °C for 3 h to obtain the composite material NiCo@C.

[0037] (4) Preparation of NiCo@C@PANI-1;

[0038] Dissolve 0.2500 g of NiCo@C powder in 50 mL of deionized water, stir for 30 min, then transfer it to an ice bath reaction system at 0 - 5 °C, add 50 mL of 0.5 mol / L hydrochloric acid solution, aspirate 0.2 mL of aniline monomer and weigh ammonium persulfate with the same amount of substance as aniline and add it to the solution, and react for 24 h to obtain the composite wave-absorbing material NiCo@C@PANI-1.

[0039] Example 2 Preparation method of an efficient composite wave-absorbing material NiCo@C@PANI-2

[0040] (1) Preparation of NiCo-BTC;

[0041] Dissolve 1.1602 g of Co(NO 3 ) 2 ·6H2 O, 0.5801 g of Ni(NO 3 ) 2 ·6H 2 O, 3.0 g of PVP (K30), 0.6 g of BTC were dissolved in 60 mL of N-N-dimethylformamide (DMF) solvent, and ultrasonically stirred for 20 min, denoted as solution A. Solution A was transferred to the inner liner of an 80 mL polytetrafluoroethylene-lined autoclave, the autoclave was tightened, and solvothermal treatment was carried out at 180 °C for 4 h. It was washed successively with DMF, deionized water, and absolute ethanol, and dried to obtain the intermediate NiCo-BTC.

[0042] (II) Preparation of NiCo@PDA;

[0043] 0.2850 g of NiCo-BTC was fully dissolved in 100 mL of deionized water containing 0.121 g of Tris. After ultrasonically stirring for 30 min, 0.2850 g of dopamine hydrochloride (DA) was added, and the powder product obtained after stirring for 24 h was NiCo@PDA.

[0044] (III) Preparation of NiCo@C;

[0045] The NiCo@PDA powder was calcined in a tubular furnace under an argon atmosphere at 850 °C for 1 h to obtain the composite material NiCo@C.

[0046] (IV) Preparation of NiCo@C@PANI-2;

[0047] 0.2500 g of NiCo@C powder was dissolved in 50 mL of deionized water, stirred for 30 min, and then transferred to an ice bath reaction system at 0 - 5 °C. 50 mL of 0.5 mol / L hydrochloric acid solution was added, 0.75 mL of aniline monomer was aspirated, and ammonium persulfate with the same amount of substance as aniline was weighed and added to the solution. After reacting for 24 h, the composite wave-absorbing material NiCo@C@PANI-2 was obtained.

[0048] Example 3 Preparation method of a highly efficient composite wave-absorbing material NiCo@C@PANI-3

[0049] (I) Preparation of NiCo-BTC;

[0050] 1.1602 g of Co(NO 3 ) 2 ·6H 2 O, 0.5801 g of Ni(NO 3 ) 2 ·6H 20, 3.0 g of PVP (K30) and 0.6 g of BTC were dissolved in 60 mL of N-N-dimethylformamide (DMF) solvent, and ultrasonically stirred for 30 min, denoted as solution A. Solution A was transferred to the inner liner of an 80 mL polytetrafluoroethylene-lined autoclave, the autoclave was tightened, and solvent heat treatment was carried out at 150 °C for 6 h. It was washed successively with DMF, deionized water, and absolute ethanol, and dried to obtain the intermediate NiCo-BTC. (II) Preparation of NiCo@PDA;

[0051] 0.2850 g of NiCo-BTC was fully dissolved in 100 mL of deionized water containing 0.121 g of Tris. After ultrasonically stirring for 30 min, 0.2850 g of dopamine hydrochloride (DA) was added, and the powder product obtained after stirring for 24 h was NiCo@PDA.

[0052] (III) Preparation of NiCo@C;

[0053] Ni 1 Co 2 @PDA powder was calcined in a tubular furnace under an argon atmosphere at 750 °C for 2 h to obtain the composite material NiCo@C.

[0054] (IV) Preparation of NiCo@C@PANI-3;

[0055] 0.2500 g of NiCo@C powder was dissolved in 50 mL of deionized water, stirred for 30 min, and then transferred to an ice bath reaction system at 0 - 5 °C. 50 mL of 0.5 mol / L hydrochloric acid solution was added, 0.5 mL of aniline monomer was aspirated, and ammonium persulfate with the same amount of substance as aniline was weighed and added to the solution. After reacting for 24 h, the composite wave-absorbing material NiCo@C@PANI-3 could be obtained.

[0056] Example 4 Preparation method of a highly efficient composite wave-absorbing material NiCo@C@PANI-4

[0057] (I) Preparation of NiCo-BTC;

[0058] 0.5800 g of Co(NO 3 ) 2 ·6H 2 O, 1.1600 g of Ni(NO 3 ) 2 ·6H 2 O, 3.0 g of PVP (K30), and 0.6 g of BTC were dissolved in 60 mL of methanol solvent, ultrasonically stirred for 30 min, denoted as solution A. Solution A was transferred to the inner liner of an 80 mL polytetrafluoroethylene-lined autoclave, the autoclave was tightened, and solvent heat treatment was carried out at 150 °C for 4 h. It was washed successively with methanol, deionized water, and absolute ethanol, and dried to obtain the intermediate NiCo-BTC.

[0059] (2) Preparation of NiCo@PDA;

[0060] Dissolve 0.2850 g of NiCo-BTC in 100 mL of deionized water containing 0.121 g of Tris. After ultrasonic stirring for 30 min, add 0.5602 g of dopamine hydrochloride (DA). The powder product obtained after stirring for 24 h is NiCo@PDA.

[0061] (3) Preparation of NiCo@C;

[0062] Calcine the NiCo@PDA powder in a tube furnace under an argon atmosphere at 850 °C for 1 h to obtain the composite material NiCo@C.

[0063] (4) Preparation of NiCo@C@PANI-4;

[0064] Dissolve 0.2500 g of NiCo@C powder in 50 mL of deionized water, stir for 30 min, and then transfer it to an ice bath reaction system at 0 - 5 °C. Add 50 mL of 0.5 mol / L hydrochloric acid solution. Pipette 0.2 mL of aniline monomer and weigh ammonium persulfate with the same amount of substance as aniline and add them to the solution. React for 24 h to obtain the composite wave-absorbing material NiCo@C@PANI-4.

[0065] Example 5 Preparation method of a high-efficiency composite wave-absorbing material NiCo@C@PANI-5

[0066] (1) Preparation of NiCo-BTC;

[0067] Dissolve 0.5801 g of Co(NO 3 ) 2 ·6H 2 O, 1.1602 g of Ni(NO 3 ) 2 ·6H 2 O, 3.0 g of PVP (K30), and 0.6 g of BTC in 60 mL of methanol solvent. Ultrasonic stir for 40 min and label it as solution A. Transfer solution A to the inner liner of an 80 mL Teflon-lined autoclave, tighten the autoclave, and perform solvent heat treatment at 120 °C for 8 h. Wash successively with methanol, deionized water, and absolute ethanol, and dry to obtain the intermediate NiCo-BTC.

[0068] (2) Preparation of NiCo@PDA;

[0069] 0.2850 g of NiCo-BTC was fully dissolved in 100 mL of deionized water containing 0.121 g of Tris. After ultrasonic stirring for 30 min, 0.5602 g of dopamine hydrochloride (DA) was added. The powder product obtained after stirring for 24 h was NiCo@PDA.

[0070] (III) Preparation of NiCo@C;

[0071] The composite material NiCo@C can be obtained by calcining the NiCo@PDA powder in a tubular furnace under an argon atmosphere at 650 °C for 4 h.

[0072] (IV) Preparation of NiCo@C@PANI-5;

[0073] 0.2500 g of NiCo@C powder was dissolved in 50 mL of deionized water and stirred for 30 min. Then it was transferred to an ice bath reaction system at 0 - 5 °C, and 50 mL of 0.5 mol / L hydrochloric acid solution was added. 0.75 mL of aniline monomer and ammonium persulfate with the same amount of substance as aniline were weighed and added to the solution. The composite wave-absorbing material NiCo@C@PANI-5 can be obtained after reacting for 24 h.

[0074] Example 6 Preparation method of a highly efficient composite wave-absorbing material NiCo@C@PANI-6

[0075] (I) Preparation of NiCo-BTC;

[0076] 0.8700 g of Co(NO 3 ) 2 ·6H 2 O, 0.8700 g of Ni(NO 3 ) 2 ·6H 2 O, 3.0 g of PVP (K30), and 0.6 g of BTC were dissolved in 60 mL of DMF solvent and ultrasonic stirred for 20 min, denoted as solution A. Solution A was transferred to the inner liner of an 80 mL polytetrafluoroethylene-lined autoclave, the autoclave was tightened, and solvent heat treatment was carried out at 150 °C for 4 h. It was washed successively with DMF, deionized water, and absolute ethanol and dried to obtain the intermediate NiCo-BTC.

[0077] (II) Preparation of NiCo@PDA;

[0078] 0.2850 g of NiCo-BTC was fully dissolved in 100 mL of deionized water containing 0.121 g of Tris. After ultrasonic stirring for 30 min, 0.5602 g of dopamine hydrochloride (DA) was added. The powder product obtained after stirring for 24 h was NiCo@PDA.

[0079] (III) Preparation of NiCo@C;

[0080] The NiCo@PDA powder is calcined in a tube furnace under an argon atmosphere at 850 °C for 1 h to obtain the composite material NiCo@C.

[0081] (IV) Preparation of NiCo@C@PANI-6;

[0082] Dissolve 0.2500 g of NiCo@C powder in 50 mL of deionized water, stir for 30 min, then transfer it to an ice bath reaction system at 0 - 5 °C. Add 50 mL of 0.5 mol / L hydrochloric acid solution, suck 0.75 mL of aniline monomer and weigh ammonium persulfate with the same amount of substance as aniline and add them to the solution. React for 24 h to obtain the composite wave-absorbing material NiCo@C@PANI-6.

[0083] Example 7 Preparation method of a high-efficiency composite wave-absorbing material NiCo@C@PANI-7

[0084] (I) Preparation of NiCo-BTC;

[0085] Dissolve 0.8700 g of Co(NO 3 ) 2 ·6H 2 O, 0.8700 g of Ni(NO 3 ) 2 ·6H 2 O, 3.0 g of PVP(K30), and 0.6 g of BTC in 60 mL of DMF solvent, ultrasonically stir for 30 min, and record it as solution A. Transfer solution A to the inner liner of an 80 mL Teflon-lined autoclave, tighten the autoclave, and perform solvent heat treatment at 180 °C for 4 h. Wash successively with DMF, deionized water, and absolute ethanol, and dry to obtain the intermediate NiCo-BTC.

[0086] (II) Preparation of NiCo@PDA;

[0087] Fully dissolve 0.2850 g of NiCo-BTC in 100 mL of deionized water containing 0.121 g of Tris. After ultrasonically stirring for 30 min, add 0.5602 g of dopamine hydrochloride (DA), and the powder product obtained after stirring for 24 h is NiCo@PDA.

[0088] (III) Preparation of NiCo@C;

[0089] The NiCo@PDA powder is calcined in a tube furnace under an argon atmosphere at 650 °C for 3 h to obtain the composite material NiCo@C.

[0090] (IV) Preparation of NiCo@C@PANI-7;

[0091] Dissolve 0.2500 g of NiCo@C powder in 50 mL of deionized water, stir for 30 min, and then transfer it to an ice bath reaction system at 0 - 5 °C. Add 50 mL of 0.5 mol / L hydrochloric acid solution, pipette 0.5 mL of aniline monomer and weigh ammonium persulfate with the same amount of substance as aniline and add them to the solution. React for 24 h to obtain the composite wave-absorbing material NiCo@C@PANI-7.

[0092] The above-described embodiments only represent the implementation modes of the present invention, but should not be construed as limiting the scope of the present invention. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A method for preparing a high-efficiency composite absorbing material NiCo@C@PANI, characterized in that: The preparation method adjusts the ratio of nickel and cobalt metal particles, changes the ratio of nickel and cobalt metal to carbon and polyaniline dielectric components, thereby achieving regulation of the electromagnetic parameters of the composite material and improving the wave absorbing performance; the method comprises the following steps: Step 1) preparing powdered NiCo-BTC as intermediate 1 by a solvothermal method; Step 2) After the intermediate 1 is completely dried, it is fully dispersed in deionized water, tris(hydroxymethyl)aminomethane) and dopamine hydrochloride are added, and the mixture is fully stirred, centrifuged, filtered, washed, and dried to obtain NiCo@PDA powder as the intermediate 2; Step 3) calcining the intermediate 2 at high temperature to obtain NiCo@C as the intermediate 3; Step 4) The intermediate 3 is fully dispersed in deionized water, and hydrochloric acid, aniline monomer, and ammonium persulfate are added to obtain a mixed solution, and the mixed solution is reacted at 0-5° C. for 24 hours; After centrifugation, filtration, washing and drying, the final product NiCo@C@PANI was obtained.

2. The method for preparing a high-efficiency composite absorbing material NiCo@C@PANI according to claim 1, characterized in that: In the step 1), the intermediate 1 is prepared by a solvothermal method, specifically: Cobalt nitrate hexahydrate Co(NO3)2·6H2O, nickel nitrate hexahydrate Ni(NO3)2·6H2O, polyvinyl pyrrolidone PVP, and trimesic acid BTC are fully dissolved in an organic solvent, wherein the molar ratio of cobalt nitrate hexahydrate Co(NO3)2·6H2O and nickel nitrate hexahydrate Ni(NO3)2·6H2O is 1:2-2:1, and the mass ratio of PVP to BTC is 5:1, which is recorded as solution 1; after sufficient stirring, pour the solution into a polytetrafluoroethylene reactor liner, tighten the reactor, and perform solvent heat treatment at 120-180°C for 4-8h. Finally, the intermediate 1 is obtained by centrifugation, water washing, alcohol washing and drying.

3. The method for preparing a high-efficiency composite absorbing material NiCo@C@PANI according to claim 2, characterized in that: In the step 1), the organic solvent includes NN-dimethylformamide and methanol.

4. The method for preparing a high-efficiency composite absorbing material NiCo@C@PANI according to claim 2, characterized in that: In the solution 1 of step 1), the concentration of Co(NO3)2·6H2O is 0.033-0.066 mol / L, and the concentration of Ni(NO3)2·6H2O is 0.033-0.066 mol / L; the stirring time is 20-40 min.

5. The method for preparing a high-efficiency composite absorbing material NiCo@C@PANI according to claim 1, characterized in that: In the step 2), the mass ratio of the intermediate 1, tris(hydroxymethyl)aminomethane and dopamine hydrochloride is 12:5:

12.

6. The method for preparing a high-efficiency composite absorbing material NiCo@C@PANI according to claim 1, characterized in that: In the step 3), the NiCo@PDA powder is calcined at 650-850° C. in an argon atmosphere in a tube furnace for 1-3 hours.

7. The method for preparing a high-efficiency composite absorbing material NiCo@C@PANI according to claim 1, characterized in that: In the step 4), 0.25 g of NiCo@C is added to every 50 ml of deionized water, the concentration of hydrochloric acid in the mixed solution formed by 50 ml of deionized water is 0.5 mol / L, the molar ratio of ammonium persulfate to aniline monomer is 1:1, and the amount of aniline monomer added is 0.2-0.75 mL.

8. The method for preparing a high-efficiency composite absorbing material NiCo@C@PANI according to claim 1, characterized in that: The mass ratio of NiCo@C to aniline monomer is controlled at 1:0.75-3.

9. The method for preparing a high-efficiency composite absorbing material NiCo@C@PANI according to claim 1, characterized in that: The mass ratio of the NiCo@C to the aniline monomer is controlled at 1:2.

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