CN107626931B - Preparation and application of cobalt-graphene composite material for absorbing electromagnetic waves - Google Patents
Preparation and application of cobalt-graphene composite material for absorbing electromagnetic waves Download PDFInfo
- Publication number
- CN107626931B CN107626931B CN201710814646.7A CN201710814646A CN107626931B CN 107626931 B CN107626931 B CN 107626931B CN 201710814646 A CN201710814646 A CN 201710814646A CN 107626931 B CN107626931 B CN 107626931B
- Authority
- CN
- China
- Prior art keywords
- cobalt
- graphene oxide
- preparing
- graphene
- wave
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The invention provides a method for preparing a cobalt-graphene composite wave-absorbing material in a normal-temperature water-phase system by using a one-step reduction method, belonging to the technical field of preparation of nano metal powder in a metal functional material. The method comprises the steps of adding an aqueous solution containing cobalt ions into an alkaline graphene oxide solution with a certain concentration at normal temperature, and then adding a reducing agent to synchronously reduce graphene oxide and metal cobalt from the solution to obtain the cobalt-graphene composite material. The cobalt-graphene composite wave-absorbing material is prepared by reducing cobalt ions and graphene oxide by a one-step method for the first time, is very simple to operate, low in energy consumption and low in cost, can be used for absorbing electromagnetic waves in a certain frequency range, and is wide in effective wave-absorbing frequency and high in efficiency.
Description
Technical Field
The invention belongs to the technical field of preparation of nano metal powder in a metal functional material, relates to a method for preparing a cobalt-graphene composite material, and particularly relates to a method for preparing a high-performance cobalt-graphene composite material by one-step reduction in a liquid phase.
Background
The wave-absorbing material has wide application prospect in civil and military fields. Firstly, in the civil field, with the progress of science and technology, more products using electromagnetic waves as media appear in people's life, and the electromagnetic waves generated by the products have great influence on human bodies and the environment. Electromagnetic radiation pollution has become the fifth largest pollution following water, atmosphere, solid waste and noise. In daily life, electronic equipment can radiate electromagnetic waves in an operating state, so that the normal operation of surrounding equipment is interfered, communication interference is caused, information safety is influenced, and even the health of a human body is threatened. In the military field, most modern novel weapons use radar waves for detection and guidance, and serious threats are caused to the existence of airplanes, naval vessels, flecks, tanks and other military equipment, so that the efficient electromagnetic wave absorbing material is very necessary, can absorb incident electromagnetic waves under the conditions of not changing the appearance of the military equipment and not influencing the functions of the military equipment, reduces the risks of detection and discovery of the military equipment, improves the survival rate of the equipment and improves the striking efficiency.
The electromagnetic wave-absorbing materials are various in types, and the following 4 types are common classification methods: (1) according to different loading capacities and preparation processes, the composite material can be divided into a structural wave-absorbing material and a coating type wave-absorbing material; (2) according to the size difference of the wave absorbing agent, the wave absorbing agent can be divided into micron-sized wave absorbing materials and nanometer-sized wave absorbing materials; (3) can be divided into ferrite, magnetic metal, alloy, ceramic, carbon material and the like according to different chemical compositions of the absorbent; (4) the absorption type wave-absorbing material can be divided into absorption type and interference type wave-absorbing materials according to different loss mechanisms, wherein the absorption type wave-absorbing material can be divided into resistance loss type, dielectric loss type and magnetic loss type wave-absorbing materials.
The evaluation of the performance of the electromagnetic wave-absorbing material can be summarized into 4 characters of 'thin, wide, strong and light'. "strong" refers to the absorption strength of electromagnetic waves, characterized by reflectivity; "wide" refers to the width of the electromagnetic wave absorption frequency band, and the frequency band with the reflection loss value (RL) below-10 dB is usually used as the effective wave absorption frequency band; "thin" means that the thickness of the coating layer for absorbing electromagnetic waves is thin; "light" means that the density of the electromagnetic absorbing material is less. At present, some electromagnetic wave-absorbing materials can achieve 'strong' electromagnetic wave absorption but cannot meet 'wide' frequency absorption, or can achieve 'strong' electromagnetic wave absorption but have too thick coating thickness, for example, the wave-absorbing efficiency of a magnetic medium wave-absorbing material taking ferrite as a core and a composite material taking silicon nitride and titanate as the core can reach 99.99 percent; some carbon materials can meet the requirement of wide frequency absorption, but the absorption strength is weak, for example, carbon materials such as graphite, carbon fiber, conductive carbon black, carbon nano tube and graphene can generally reach about 90% of wave-absorbing efficiency.
The metal cobalt is a typical magnetic metal wave-absorbing material, but the electromagnetic wave-absorbing performance of the metal cobalt is not ideal, and although the wave-absorbing strength is high, the effective absorption frequency band is narrow, the absorption to a low-frequency region is weak, and the like, so that the practical application of the metal cobalt is limited. Graphene, a typical two-dimensional material, has the characteristics of light weight, good conductivity, large specific surface area, large dielectric constant and the like due to its thickness of a single atomic layer and special pore walls. However, as mentioned above, when graphene is used alone as a wave-absorbing material, the impedance matching characteristic is poor due to the extremely high conductivity of graphene, and although the graphene can achieve wider frequency absorption, the wave-absorbing strength is low and cannot meet the requirements of the wave-absorbing material. Therefore, the graphene is compounded with a magnetic metal material such as metal cobalt to obtain a new composite material, the synergistic effect of resistance loss and magnetic loss is exerted, the impedance matching and wave absorbing performance of the material is improved, multi-band and high-efficiency absorption of electromagnetic waves is realized, and the requirements of thin coating and low density can be met.
At present, a hydrothermal method or a thermal decomposition method is generally adopted for preparing the graphene and magnetic metal composite wave-absorbing material, the preparation conditions are complex, the operation steps are complex, the energy consumption is high, and the obtained composite material does not realize multiband, broadband and strong absorption of electromagnetic waves within the range of 2-18 GHz. For example, X.C.ZHao et al adopts a hydrothermal reduction method to compound iron and graphene, the minimum reflection loss value (RL) of the material is-45 dB, the thickness of the coating is 3mm, and the effective wave-absorbing bandwidth (RL is less than or equal to-10 dB) is 2.5 GHz; wang et al used hydrothermal reaction and annealing process to compound porous nickel oxide with graphene, the minimum reflection loss value (RL) of the material was-16.5 dB, the coating thickness was 1.5mm, and the effective wave-absorbing bandwidth (RL ≦ 10dB) was 5.1 GHz; wang et al used a microemulsion method to compound cobaltosic oxide with graphene, the minimum reflection loss value (RL) of the material was-7.3 dB, and the thickness of the coating was 2 mm. Chen et al prepared a nickel-graphene composite material by a hydrothermal method, wherein the minimum reflection loss value (RL) -17.8dB, the coating thickness was 5mm, and the effective wave-absorbing bandwidth (RL < minus 10dB) was 2.3 GHz.
The invention adopts a low-temperature liquid phase reduction method for the first time, prepares the cobalt-graphene composite material by one-step reduction, has simple operation, low energy consumption and low cost, and can realize multiband, broadband and strong absorption of electromagnetic waves by applying the prepared cobalt-graphene composite material to the absorption of the electromagnetic waves in the frequency range of 2-18 GHz.
Disclosure of Invention
The invention provides a method for preparing a cobalt-graphene composite wave-absorbing material in a liquid phase by adopting a one-step reduction method, and aims to obtain the cobalt-graphene composite wave-absorbing material with good electromagnetic wave-absorbing performance.
The principle of the invention is as follows: cobalt ions in the liquid phase and the dispersed graphene oxide are simultaneously reduced by using a reducing agent, and the cobalt ions and the dispersed graphene oxide form a composite material. Firstly, ultrasonically dispersing graphene oxide in an aqueous solution, adjusting the pH value to be alkaline, preparing an aqueous solution from a cobalt salt, a complexing agent and a dispersing agent, then adding the aqueous solution into a graphene oxide dispersion solution, stirring for 5-10min, then adding a reducing agent with the molar ratio of 1.5 times that of cobalt ions and above, reacting for more than 60min, separating by using a magnet after the reaction is finished to obtain a product, repeatedly carrying out ultrasonic cleaning by using ethanol and deionized water, and carrying out vacuum drying to obtain the black fluffy cobalt-graphene composite material.
The cobalt-graphene composite wave-absorbing material is prepared at normal temperature based on a liquid-phase reduction method, can be produced in batches, greatly simplifies the preparation process of the cobalt-graphene composite wave-absorbing material, and avoids the problem of high energy consumption caused by the conventional hydrothermal method or thermal decomposition method at home and abroad. The prepared cobalt-graphene composite wave-absorbing material has electromagnetic wave absorption peaks in an S wave band (2-4GHz), an X wave band (8-12GHz) and a Ku wave band (12-18GHz) within the range of 2-18GHz of the frequency of electromagnetic waves, the effective absorption bandwidth is 4-7GHz, and the maximum effective absorption efficiency can reach 99.99%.
The specific preparation process of the invention comprises the following steps:
a cobalt complex solution is first prepared. Dissolving any one of cobalt chloride, cobalt sulfate, cobalt acetate and cobalt nitrate and a complexing agent (comprising sodium lactate, sodium malate, sodium citrate, succinic acid, ethylenediamine and ethylene diamine tetraacetic acid disodium) in deionized water at the temperature of 60-80 ℃, adding a dispersing agent (comprising stearic acid monoglyceride, zinc stearate and polyvinylpyrrolidone) and stirring to dissolve, wherein the molar ratio of the cobalt chloride to the sodium malate to the succinic acid monoglyceride to the zinc stearate to the polyvinylpyrrolidone is 1:1:0.02, and preparing 0.08-0.20mol/L of cobalt complex solution.
And preparing a graphene oxide dispersion liquid. Adding graphene oxide into deionized water, and performing ultrasonic dispersion for 30-60min to obtain a dark brown transparent solution, and preparing a 0.05-0.5mg/L graphene oxide dispersion liquid. .
Preparing graphene oxide alkaline dispersion liquid. Weighing a certain amount of solid alkali, adding the solid alkali into the graphene oxide dispersion liquid under the condition of vigorous stirring, cooling to normal temperature, and preparing to obtain the graphene oxide dispersion liquid with the alkali concentration of 0.5-2 mol/L.
And adding the cobalt complex solution into the graphene oxide alkaline dispersion liquid, uniformly stirring, and adding a reducing agent for reaction. Adding a reducing agent according to the molar ratio of 2-4:1 to the cobalt ions, and keeping the water bath temperature to 25-30 ℃ for reaction under mechanical stirring for 60-90 min.
And (5) separating and cleaning. Separating with strong magnet to obtain product, and recovering alkali solution. And respectively carrying out ultrasonic cleaning and washing on the product for 2-3 times by using absolute ethyl alcohol and deionized water, wherein each time lasts for 5-8 minutes.
And (5) drying in vacuum. And (3) carrying out vacuum freeze-drying on the washed product under the condition that the vacuum degree is 15-20Pa, and finally obtaining the black fluffy cobalt-graphene composite material.
The electromagnetic wave absorbing performance is applied. The composite material and paraffin are uniformly mixed according to the mass ratio of 1:1 to 1:9, then the mixture is pressed into a coaxial circular ring sample with the inner diameter of 3mm, the outer diameter of 7mm and the thickness of 2mm, and the wave absorbing performance of the sample is tested by utilizing a PNA-N5244A model vector network analyzer of Agilent.
Drawings
Fig. 1 is a Scanning Electron Microscope (SEM) image of the synthesized cobalt-graphene composite wave-absorbing material.
FIG. 2 is a Transmission Electron Microscope (TEM) image of the synthesized cobalt-graphene composite wave-absorbing material.
Fig. 3 is a magnetic hysteresis loop plot (VSM) of the synthesized cobalt-graphene composite wave-absorbing material.
Fig. 4 is a Reflection Loss (RL) analysis diagram of the synthesized cobalt-graphene composite wave-absorbing material.
Detailed Description
At normal temperature, reducing cobalt ions in the liquid phase and the dispersed graphene oxide by using a reducing agent simultaneously to form a composite material, so as to obtain a cobalt-graphene composite wave-absorbing material with good electromagnetic wave-absorbing performance; the preparation method of the cobalt-graphene composite wave-absorbing material comprises the following steps:
(1) preparing a cobalt complex solution: dissolving soluble cobalt salt and a complexing agent in deionized water at 60-80 ℃, adding a dispersing agent, stirring and dissolving, wherein the molar ratio of the soluble cobalt salt to the complexing agent to the dispersing agent is 1:1:0.02, and preparing a 0.08-0.20mol/L cobalt complex solution; the soluble cobalt salt is one of cobalt chloride, cobalt sulfate, cobalt acetate or cobalt nitrate; the coordination agent is one of sodium lactate, sodium malate, sodium citrate, succinic acid, ethylenediamine or disodium ethylene diamine tetraacetate; the dispersing agent is one of stearic acid monoglyceride, zinc stearate or polyvinylpyrrolidone;
(2) preparing a graphene oxide dispersion liquid: adding graphene oxide into deionized water, and performing ultrasonic dispersion for 30-60min to obtain a dark brown transparent solution, and preparing a graphene oxide dispersion liquid of 0.05-0.5 mg/L;
(3) preparing graphene oxide alkaline dispersion liquid: weighing a certain amount of solid alkali, adding the solid alkali into the graphene oxide dispersion liquid under the condition of vigorous stirring, cooling to normal temperature, and preparing to obtain the graphene oxide dispersion liquid with the alkali concentration of 0.5-2 mol/L;
(4) preparing a cobalt-graphene composite material by one-step reduction: adding the cobalt complex solution into the graphene oxide alkaline dispersion liquid, uniformly stirring, and adding a reducing agent for reaction; adding a reducing agent according to the molar ratio of 2-4:1 to cobalt ions, and keeping the water bath temperature to 25-30 ℃ for reaction for 60-90min under the condition of mechanical stirring; separating with strong magnet to obtain product, and recovering alkali solution; respectively ultrasonically cleaning and washing the product with anhydrous ethanol and deionized water for 2-3 times, each time for 5-8 min; carrying out vacuum freeze-drying on the washed product under the condition that the vacuum degree is 15-20Pa, and finally obtaining a black and fluffy cobalt-graphene composite material; the reducing agent is hydrazine hydrate or sodium borohydride.
Claims (1)
1. A preparation method of a cobalt-graphene composite wave-absorbing material is characterized in that cobalt ions in a liquid phase and dispersed graphene oxide are simultaneously reduced by a reducing agent at normal temperature to form a composite material, so that the cobalt-graphene composite wave-absorbing material with good electromagnetic wave-absorbing performance is obtained;
the preparation method of the cobalt-graphene composite wave-absorbing material comprises the following steps:
(1) preparing a cobalt complex solution: dissolving soluble cobalt salt and a complexing agent in deionized water at 60-80 ℃, adding a dispersing agent, stirring and dissolving, wherein the molar ratio of the soluble cobalt salt to the complexing agent to the dispersing agent is 1:1:0.02, and preparing a 0.08-0.20mol/L cobalt complex solution;
the soluble cobalt salt is one of cobalt chloride, cobalt sulfate, cobalt acetate or cobalt nitrate;
the coordination agent is one of sodium lactate, sodium malate, sodium citrate, succinic acid, ethylenediamine or disodium ethylene diamine tetraacetate;
the dispersing agent is one of stearic acid monoglyceride, zinc stearate or polyvinylpyrrolidone;
(2) preparing a graphene oxide dispersion liquid: adding graphene oxide into deionized water, and performing ultrasonic dispersion for 30-60min to obtain a dark brown transparent solution, and preparing a graphene oxide dispersion liquid of 0.05-0.5 mg/L;
(3) preparing graphene oxide alkaline dispersion liquid: weighing a certain amount of solid alkali, adding the solid alkali into the graphene oxide dispersion liquid under the condition of vigorous stirring, cooling to normal temperature, and preparing to obtain the graphene oxide dispersion liquid with the alkali concentration of 0.5-2 mol/L;
(4) preparing a cobalt-graphene composite material by one-step reduction: adding the cobalt complex solution into the graphene oxide alkaline dispersion liquid, uniformly stirring, and adding a reducing agent for reaction; adding a reducing agent according to the molar ratio of 2-4:1 to cobalt ions, and keeping the water bath temperature to 25-30 ℃ for reaction for 60-90min under the condition of mechanical stirring; separating with strong magnet to obtain product, and recovering alkali solution; respectively ultrasonically cleaning and washing the product with anhydrous ethanol and deionized water for 2-3 times, each time for 5-8 min; carrying out vacuum freeze-drying on the washed product under the condition that the vacuum degree is 15-20Pa, and finally obtaining a black and fluffy cobalt-graphene composite material;
the reducing agent is hydrazine hydrate or sodium borohydride.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710814646.7A CN107626931B (en) | 2017-09-12 | 2017-09-12 | Preparation and application of cobalt-graphene composite material for absorbing electromagnetic waves |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710814646.7A CN107626931B (en) | 2017-09-12 | 2017-09-12 | Preparation and application of cobalt-graphene composite material for absorbing electromagnetic waves |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107626931A CN107626931A (en) | 2018-01-26 |
| CN107626931B true CN107626931B (en) | 2020-12-08 |
Family
ID=61101149
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710814646.7A Active CN107626931B (en) | 2017-09-12 | 2017-09-12 | Preparation and application of cobalt-graphene composite material for absorbing electromagnetic waves |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107626931B (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109005660B (en) * | 2018-09-04 | 2019-08-06 | 北京科技大学 | Cobalt nano-particle and redox graphene electromagnetic wave absorbent material preparation method |
| CN110577821B (en) * | 2019-09-24 | 2022-10-04 | 国网重庆市电力公司电力科学研究院 | Composite wave-absorbing material and preparation method thereof |
| CN110835123B (en) * | 2019-12-09 | 2022-03-25 | 哈尔滨工业大学（威海） | Preparation method of cobalt metal particles and cobalt oxide composite graphite nanosheet powder |
| CN111613901B (en) * | 2020-04-16 | 2022-03-01 | 北京服装学院 | Graphene/metal oxide/metal ternary nano composite magnetic material and preparation method thereof |
| CN114085649A (en) * | 2020-08-25 | 2022-02-25 | 安徽璜峪电磁技术有限公司 | Non-metal graphene-based composite wave-absorbing material and preparation method thereof |
| CN113604089B (en) * | 2021-07-02 | 2022-03-08 | 中国科学院重庆绿色智能技术研究院 | Broadband optical absorbent and coating preparation method |
| CN113436824A (en) * | 2021-07-07 | 2021-09-24 | 上海圣石生物医学科技有限公司 | Magnetic wave-absorbing material, preparation method, application and health-care product thereof |
| CN113634744A (en) * | 2021-07-13 | 2021-11-12 | 中北大学 | Preparation method of graphene surface cobalt-plated reinforced cobalt-based alloy composite powder for selective laser melting forming |
| CN114682788A (en) * | 2021-12-21 | 2022-07-01 | 北京航空航天大学 | Samarium iron/graphene nano composite material for electromagnetic wave absorption and preparation method thereof |
| CN114437665B (en) * | 2022-01-10 | 2023-02-17 | 北京理工大学 | Combustion type plasma electromagnetic damage cloud cluster and preparation method and application thereof |
| CN114340371B (en) * | 2022-01-21 | 2022-10-04 | 中星(广州)纳米材料有限公司 | Graphene oxide-high-entropy alloy nanocomposite for electromagnetic wave shielding and preparation method and application thereof |
| CN115058143A (en) * | 2022-05-24 | 2022-09-16 | 晶展(哈尔滨)科技有限责任公司 | Electromagnetic wave absorbent, preparation method thereof and method for preparing wave-absorbing coating by using electromagnetic wave absorbent |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103554908A (en) * | 2013-11-13 | 2014-02-05 | 北京科技大学 | Graphene/polyaniline/cobalt composite wave-absorbing material and preparation method |
| CN104209531A (en) * | 2013-05-31 | 2014-12-17 | 北京化工大学 | Cobalt/graphene composite nano wave-absorbing material and preparation method thereof |
| CN105908041A (en) * | 2016-04-27 | 2016-08-31 | 富耐克超硬材料股份有限公司 | High-tenacity polycrystalline composite material, high-tenacity polycrystalline blade and preparation method of high-tenacity polycrystalline blade |
| CN106541145A (en) * | 2016-10-28 | 2017-03-29 | 四川大学 | A kind of graphene oxide magnetic metal nanowire composite and preparation method thereof |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101337994B1 (en) * | 2010-04-14 | 2013-12-06 | 한국과학기술원 | Graphene/metal nanocomposite powder and method of manufacturing thereof |
| CN102229425B (en) * | 2011-03-29 | 2013-01-02 | 东华大学 | Method for preparing cobalt/graphene composite material by alcohol thermal method |
| CN102530934A (en) * | 2012-01-09 | 2012-07-04 | 苏州大学 | Method for preparing graphene |
| CN103286308B (en) * | 2012-02-24 | 2015-08-26 | 中国科学院理化技术研究所 | A kind of Metal/grapheme nanocomposite and preparation method thereof |
| CN104084575B (en) * | 2014-06-30 | 2016-03-23 | 北京师范大学 | Emission in Cubic cobalt/graphene composite material, preparation method and absorbing property |
| CN104084576B (en) * | 2014-06-30 | 2016-03-23 | 北京师范大学 | Six side's phase cobalt/graphene composite materials, preparation method and absorbing property |
| CN105295832A (en) * | 2014-07-25 | 2016-02-03 | 南京理工大学 | Preparation method for reduced graphene oxide/Ni-Co ternary composite wave-absorbing material |
| CN104263317B (en) * | 2014-09-26 | 2016-03-09 | 厦门大学 | The synthetic method of a kind of cobalt oxide/Graphene composite wave-suction material |
| CN104690264B (en) * | 2015-03-06 | 2016-11-23 | 苏州欢颜电气有限公司 | A kind of thermally-stabilised conduction absorbing material CoFe2o4the preparation method of/Ag/ graphene composite material |
| CN105923624B (en) * | 2016-04-21 | 2018-06-19 | 重庆理工大学 | A kind of preparation method of modified graphene |
-
2017
- 2017-09-12 CN CN201710814646.7A patent/CN107626931B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104209531A (en) * | 2013-05-31 | 2014-12-17 | 北京化工大学 | Cobalt/graphene composite nano wave-absorbing material and preparation method thereof |
| CN104209531B (en) * | 2013-05-31 | 2016-08-17 | 北京化工大学 | A kind of cobalt/Graphene composite nano wave-absorbing material and preparation method thereof |
| CN103554908A (en) * | 2013-11-13 | 2014-02-05 | 北京科技大学 | Graphene/polyaniline/cobalt composite wave-absorbing material and preparation method |
| CN105908041A (en) * | 2016-04-27 | 2016-08-31 | 富耐克超硬材料股份有限公司 | High-tenacity polycrystalline composite material, high-tenacity polycrystalline blade and preparation method of high-tenacity polycrystalline blade |
| CN106541145A (en) * | 2016-10-28 | 2017-03-29 | 四川大学 | A kind of graphene oxide magnetic metal nanowire composite and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107626931A (en) | 2018-01-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107626931B (en) | Preparation and application of cobalt-graphene composite material for absorbing electromagnetic waves | |
| CN108834389B (en) | Preparation method of bimetal organic framework derived porous carbon/multi-walled carbon nanotube nano composite wave-absorbing material | |
| CN109705808B (en) | Cobalt-nickel alloy-porous carbon composite wave-absorbing material with MOF structure and preparation method thereof | |
| CN112961650B (en) | Three-metal organic framework derived iron-nickel alloy/porous carbon ultrathin wave absorber and preparation method thereof | |
| CN110290691B (en) | Lamellar MXene-loaded cobalt ferrite composite wave-absorbing material and preparation method thereof | |
| CN105219345B (en) | Preparation method of ferroferric oxide @ iron core shell structure-graphene composite absorbing material | |
| CN108690556A (en) | A kind of preparation method of redox graphene/multi-walled carbon nanotube/Ni ferrite ternary nano composite wave-suction material | |
| CN109005660B (en) | Cobalt nano-particle and redox graphene electromagnetic wave absorbent material preparation method | |
| CN109936974B (en) | Synthetic method of sandwich structure CoFe @ C/graphene electromagnetic wave absorption material | |
| CN105950112B (en) | A kind of nano combined absorbing material and preparation method thereof | |
| CN113088252A (en) | Iron-cobalt-nickel alloy/carbon/graphene ultrathin wave-absorbing material and preparation method thereof | |
| CN114195197B (en) | Magnetic porous carbon compound and preparation method and application thereof | |
| CN112430451A (en) | Nitrogen-doped graphene/cobalt-zinc ferrite composite aerogel wave-absorbing material and preparation method thereof | |
| CN112897569B (en) | Preparation method of nickel/zinc oxide/carbon/reduced graphene oxide ultrathin wave absorber | |
| CN114449877A (en) | Core-shell Ni/Co alloy @ nitrogen-doped carbon-based wave-absorbing composite material and preparation method thereof | |
| CN112752496A (en) | Hollow nitrogen-doped nickel oxide/nickel/carbon composite material, preparation method and application | |
| CN113068385A (en) | One-dimensional yolk-shell Ni @ void @ Co3O4@ RGO wave absorbing agent and preparation method thereof | |
| CN112449568A (en) | Method for preparing hollow cobalt-nickel alloy/porous carbon composite wave-absorbing material | |
| CN110253032B (en) | Method for preparing flower-like nickel nanoparticles at normal temperature and normal pressure in high yield | |
| CN110340376B (en) | Flower-shaped nickel wire wave-absorbing material and preparation method thereof | |
| CN112980389A (en) | Preparation method of functionalized graphene wave-absorbing material | |
| CN112875768B (en) | One-dimensional coralliform NiS/Ni3S4@PPy@MoS2Wave absorber, preparation method and application | |
| CN114479762A (en) | Magnetic metal/metal oxide/carbon nano composite material, preparation method and application thereof | |
| CN113597247A (en) | Magnetic metal nanoparticle modified carbon hollow sphere wave-absorbing material and preparation method thereof | |
| Xu et al. | A chiral microwave absorbing absorbent of Fe–CoNiP coated on spirulina |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |