Core-shell Ni/Co alloy and nitrogen-doped carbon-based wave-absorbing composite material and preparation method thereof

A technology of nitrogen-doped carbon and composite materials, applied in the fields of magnetic/electric field shielding, electrical components, etc., can solve the problems of narrow effective absorption bandwidth, complicated synthesis steps, and unfriendly environment, so as to improve the absorption performance and optimize the impedance Matching, environment-friendly effect

Pending Publication Date: 2022-05-06
GUIZHOU UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problems of complex synthesis steps, poor stability, unfriendly environment, narrow effective absorbing bandwidth, and poor absorbing intensity of existing absorbing materials, the present invention proposes a core-shell Ni / Co alloy@nitrogen-doped carbon-based absorbing compound Material preparation method

Method used

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  • Core-shell Ni/Co alloy and nitrogen-doped carbon-based wave-absorbing composite material and preparation method thereof
  • Core-shell Ni/Co alloy and nitrogen-doped carbon-based wave-absorbing composite material and preparation method thereof
  • Core-shell Ni/Co alloy and nitrogen-doped carbon-based wave-absorbing composite material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] (1) Preparation of Co / Ni-MOF precursor

[0032] 1.21g CH 3 COONa·3H 2 O and 1.22g of nicotinic acid were dissolved in 100ml of deionized water and stirred for 30 minutes to obtain A solution. At the same time, 2.1gNi(NO 3 ) 2 ·6H 2 O, 1.2gCo(NO 3 ) 2 ·6H 2 O and 1.1 g of polyvinylpyrrolidone (PVP) were dissolved in 100 ml of deionized water, and stirred for 30 minutes to obtain solution B. Solution B was slowly added to solution A and stirred for 30 minutes. Then the uniformly stirred mixed solution was transferred to a 250 ml polytetrafluoroethylene stainless steel autoclave, and reacted at 120° C. for 6 hours. After natural cooling to room temperature, a gray-blue precipitate was obtained, which was washed three times with deionized water, and vacuum-dried at 60 °C for 24 hours to obtain the CoNi-MOF precursor.

[0033] (2) Preparation of Ni / Co alloy@nitrogen-doped carbon-based microwave-absorbing composite material

[0034] The Ni / Co-MOF precursor is place...

Embodiment 2

[0042] (1) Preparation of Co / Ni-MOF precursor

[0043] CH 3 COONa·3H 2 O is 2.42g, niacin is 2.44g, Ni(NO 3 ) 2 ·6H 2 O is 3.15g, Co(NO 3 ) 2 ·6H 2 Og is 2.4, and other is with embodiment 1.

[0044] (2) Preparation of core-shell Ni / Co alloy@nitrogen-doped carbon-based microwave-absorbing composite

[0045]The Ni / Co-MOF precursor was placed in a crucible, pyrolyzed at 600 °C for 2 hours in an argon atmosphere, and the heating rate was 2 °C / min, and then naturally cooled to obtain a Ni / Co alloy with a core-shell structure@nitrogen-doped Heterocarbon-based microwave-absorbing composite (Ni / Co@C-600).

[0046] (3) Ni / Co@C-600 absorbing performance test

[0047] The absorbing material used is the composite material prepared in Example 2. Others are the same as in Example 1. When the absorbing material is measured at a frequency of 8.9GHz and a thickness of 3.5mm, the optimal RL value can reach -71.9dB, RL The effective absorbing bandwidth of <-10 is up to 16GHz, coverin...

Embodiment 3

[0049] (1) Preparation of CoNi-MOF precursor

[0050] CH 3 COONa·3H 2 O is 3.63g, niacin is 3.66g, Ni(NO 3 ) 2 ·6H 2 O is 4.2g, Co(NO 3 ) 2 ·6H 2 Og is 3.6, and other is with embodiment 1.

[0051] (2) Preparation of Ni / Co alloy@nitrogen-doped carbon-based microwave-absorbing composite material

[0052] The Ni / Co-MOF precursor is placed in a crucible, pyrolyzed at 650°C for 2 hours in an argon atmosphere, and the heating rate is 2°C / min, and then naturally cooled to obtain Ni / Co alloy@nitrogen-doped carbon-based absorber Composite material (Ni / Co@C-650).

[0053] (3) Ni / Co@C-650 absorbing performance test

[0054] The wave-absorbing material used is the composite material prepared in Example 3. Others are the same as in Example 1. When the frequency of the wave-absorbing material is 16.4GHz and the thickness is 2mm, the optimal RL value can reach -66.3dB.

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Abstract

The invention discloses a core-shell Ni / Co alloy and nitrogen-doped carbon-based wave-absorbing composite material and a preparation method thereof.The preparation method comprises the steps that firstly, a Ni / Co-MOF precursor is prepared through a simple hydrothermal reaction, and then the core-shell Ni / Co-C composite wave-absorbing material is obtained through high-temperature treatment in an argon inert environment; when the thickness of the composite wave-absorbing material is 3.5 mm, the frequency is 8.9 GHz, and the optimal effective wave-absorbing bandwidth (RL) value can reach-71.9 dB, RLlt; the effective wave-absorbing bandwidth of-10 reaches up to 16 GHz, S, C, X and Ku frequency bands are covered, and due to the fact that a core-shell structure with nickel and cobalt wrapped by carbon is formed, the material has good stability. The wave-absorbing material prepared by the method disclosed by the invention is environment-friendly, good in stability, relatively wide in wave-absorbing bandwidth, high in reflection loss, simple in process and suitable for large-scale production.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic absorbing materials, and more specifically relates to a core-shell Ni / Co alloy@nitrogen-doped carbon-based absorbing composite material and a preparation method thereof. Background technique [0002] In recent years, with the rapid development of microelectronics technology, 5G mobile technology, and civilian and military precision equipment, electromagnetic pollution may endanger human health and even lead to information leakage. At present, great efforts have been made to obtain ideal electromagnetic wave absorbing materials with high, thin, wide, and light weight. However, for absorbing materials, it is difficult to satisfy a wide effective absorbing bandwidth (EAB) and satisfactory reflection loss (RL) at the same time. [0003] Among the studied absorbing materials, carbon-based materials dominated by electrical loss have been widely used due to their low density, good chemical stabi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H05K9/00
CPCH05K9/0081
Inventor 秦兰何敏于杰刘玉飞娄金分秦舒浩
Owner GUIZHOU UNIV
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