CN-122028396-A - Preparation method of NiCo@C@C/MXene material with excellent electromagnetic wave absorption performance

Abstract

The invention discloses a NiCo@C@C/MXene composite material with excellent electromagnetic wave absorption performance and a preparation method thereof. The material provides a multi-component heterogeneous interface engineering strategy, and utilizes polydopamine to coat Prussian blue analog precursors and combine MXene, and NiCo@C@C/MXene composite material with a layered structure is prepared through high-temperature pyrolysis. Aiming at the problems of organic ligand loss, low carbon content, easy collapse of structure, insufficient mechanical strength and conductivity and the like of the traditional PBA derivative material, the method effectively inhibits the structural damage at high temperature by introducing a PDA shell layer rich in carbon source, and simultaneously builds a stable conductive network by utilizing the excellent conductivity of MXene. The finally prepared composite material constructs rich heterogeneous interfaces and defect sites among NiCo nano particles, a mixed crystallinity carbon matrix and an MXene layer, and obviously optimizes impedance matching and attenuation capacity through the synergistic effect of interface polarization loss and multiple loss mechanisms.

Inventors

• JIA ZHIQING
• Gong Xinju
• GUO SIYAO
• WANG WENRUI
• BAO YUNFENG

Assignees

• 青岛理工大学

Dates

Publication Date

20260512

Application Date

20260206

Claims (7)

1. 1. The NiCo@C@C/MXene composite electromagnetic wave absorbing material is characterized in that the composite material is prepared by compounding a NiCo-PBA@PDA core-shell structure and a lamellar MXene and then carrying out high-temperature pyrolysis, and has a multicomponent heterogeneous interface structure comprising NiCo nano particles, a mixed crystallinity carbon matrix and a MXene layer.
2. 2. The preparation method of the NiCo@C@C/MXene composite electromagnetic wave absorbing material as claimed in claim 1, which is characterized by comprising the following steps: (1) Preparing a NiCo-PBA precursor, namely dissolving nickel nitrate hexahydrate and sodium citrate dihydrate in deionized water to form a solution A, and dissolving potassium cobalt cyanide in the deionized water to form a solution B; (2) Dispersing the NiCo-PBA precursor obtained in the step (1) in a mixed solution of water and ethanol to obtain a dispersion liquid A, dissolving dopamine hydrochloride and polyvinylpyrrolidone in the mixed solution of water and ethanol to obtain a solution B, mixing the dispersion liquid A and the solution B, adding formaldehyde and an ammonium hydroxide aqueous solution, stirring for reaction, and centrifugally washing and drying to obtain the NiCo-PBA@PDA precursor; (3) Dispersing lithium fluoride powder in a mixed solution of water and hydrochloric acid, adding Ti 3 AlC 2 powder, stirring for reaction, centrifugally washing until the pH value is close to 6, dispersing the precipitate in deionized water, centrifugally collecting supernatant, and obtaining the MXene nano-sheet dispersion; (4) The preparation method of the NiCo@C@C/MXene composite material comprises the steps of dispersing a NiCo-PBA@PDA precursor obtained in the step (2) in deionized water, adding the MXene nano sheet dispersion liquid obtained in the step (3), stirring and mixing, centrifuging, freeze-drying to obtain precursor powder, and carrying out heat treatment on the precursor powder in an inert atmosphere to obtain the NiCo@C@C/MXene composite electromagnetic wave-absorbing material.
3. 3. The preparation method of claim 2, wherein in the step (1), the molar ratio of the nickel nitrate hexahydrate, the sodium citrate dihydrate and the potassium cobalt cyanide is 0.5-0.7:0.8-1.0:0.3-0.5, the aging time is 20-28 hours, and the drying temperature is 60-80 ℃.
4. 4. The preparation method of the aqueous dispersion according to claim 2, wherein in the step (2), the volume ratio of solvent water to ethanol in the dispersion liquid A is 4:1-6:1, the concentration of the NiCo-PBA precursor is 3-8 mg/mL, the volume ratio of solvent water to ethanol in the solution B is 1:0.8-1:1.2, the mass ratio of dopamine hydrochloride to polyvinylpyrrolidone is 0.2-0.4:0.4-0.6, the addition amounts of formaldehyde and ammonium hydroxide are 0.8-1.2 mL, the stirring reaction temperature is 30-50 ℃ for 4-8 hours, the drying temperature is 60-80 ℃ and the time is 20-28 hours.
5. 5. The preparation method of the lithium fluoride/hydrochloric acid composite material is characterized in that in the step (3), the volume ratio of solvent water to hydrochloric acid is 1:2-1:4, ti 3 AlC 2 powder is added after the lithium fluoride and the hydrochloric acid are mixed and reacted for 20-30 minutes, then stirring and etching reaction is carried out for 45-55 hours at 35-40 ℃, and the centrifugal rotating speed is 3300-3500 r/min.
6. 6. The preparation method of claim 2, wherein in the step (4), the mass ratio of the NiCo-PBA@PDA precursor to the MXene nanoplatelets is 1:1-5:1, and the stirring and mixing time is 4-8 hours.
7. 7. The preparation method according to claim 2, wherein in the step (4), the inert atmosphere is argon, the heat treatment temperature is 600-800 ℃, the heating rate is 1-3 ℃ per minute, and the heat preservation time is 1-3 hours.

Description

Preparation method of NiCo@C@C/MXene material with excellent electromagnetic wave absorption performance Technical Field The invention belongs to the technical field of application of electromagnetic wave absorbing materials, and particularly relates to preparation and application of a NiCo@C@C/MXene composite electromagnetic wave absorbing material with excellent electromagnetic wave absorbing performance. Background The disclosure of this background section is only intended to increase the understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art already known to those of ordinary skill in the art. With the rapid development of modern electronic information technology, especially the wide application of wireless communication technology such as 5G network, various advanced electronic and communication devices bring great convenience to the life and industrial manufacture of people. However, while enjoying the technical convenience, the problem of electromagnetic radiation pollution generated therewith is also increasing, and has become a non-negligible environmental and safety problem. Electromagnetic radiation pollution not only can interfere with the operation precision of electronic equipment and disturb the transmission and reception of communication signals, but also can form a potential threat to human health, so that the development of efficient electromagnetic wave absorbing materials to solve the problem of electromagnetic interference has become important. The ideal electromagnetic wave absorbing material has the characteristics of thinness, lightness, width and strength, namely small matching thickness, low density, wide effective absorption bandwidth and high absorption strength. In order to achieve excellent electromagnetic wave absorption properties, the construction of multicomponent composite materials has become a major research trend. Engineered porous crystalline materials, particularly Prussian blue analogues, are distinguished by their unique architecture and tunable composition as very attractive precursors. Pyrolysis can convert PBAs into carbon-metal complexes consisting of magnetic nanoparticles embedded in a carbon matrix, a process that can create rich defects and heterogeneous interfaces that synergistically enhance the electromagnetic loss mechanism. Although related progress is made, the conventional PBA derivative materials often have the problems of serious loss of organic ligands, reduced carbon content, reduced conductivity, easy collapse of structures at high temperature and the like, and in addition, the PBA derivative materials generally have limited mechanical strength and lower conductivity, so that practical application of the PBA derivative materials in complex environments is limited. MXene, an emerging two-dimensional material family, has excellent mechanical properties and metal-level conductivity, and has great potential in electromagnetic wave absorption. However, pure MXene materials present severe stacking, excessive conductivity, and non-magnetic characteristics, which can hinder impedance matching and reduce absorption efficiency. Although prior studies have attempted to combine carbon-based materials or metal-organic frameworks with MXene to improve performance, challenges remain in designing a material that overcomes the shortcomings of a single component and that synergistically optimizes impedance matching and attenuation capabilities through multi-component heterogeneous interface engineering, by fully utilizing the advantages of each component. Therefore, developing a composite wave-absorbing material with reasonable preparation flow and excellent electromagnetic wave absorption performance has important application value. Disclosure of Invention The invention aims to provide a NiCo@C@C/MXene composite electromagnetic wave absorbing material and a preparation method thereof, wherein Prussian Blue Analogue (PBA) derivative material is combined with MXene, and the technical problems of poor structural stability, low conductivity, easiness in stacking of the MXene material, poor impedance matching and the like of the conventional PBA derivative material are solved by utilizing a multi-component heterogeneous interface engineering strategy, so that the electromagnetic wave absorbing performance is remarkably improved. In order to achieve the above purpose, the present invention provides the following technical solutions: according to one of the technical schemes, the invention provides a NiCo@C@C/MXene composite electromagnetic wave absorbing material which is characterized in that the composite material is prepared by compounding a NiCo-PBA@PDA core-shell structure and a lamellar MXene and then carrying out high-temperature pyrolysis, and the composite material has a multicomponent heterogeneous interface structure comprising NiCo na