阅读说明：本技术 一种磁性石墨烯及其制备方法 (Magnetic graphene and preparation method thereof ) 是由 金闯 张敬杰 于 2021-07-30 设计创作，主要内容包括：本发明提供了一种磁性石墨烯及其制备方法,包括：将氧化石墨烯加入油胺和二苄醚中,混合均匀后得到分散体A；将Fe(acac)-3溶解到分散体A中,搅拌/超声处理分散均匀制得分散体B；然后将获得的浅棕色分散体B转移到密闭高压容器中,然后用氮气/氩气冲洗以除去痕量的氧气和水分,制得分散体C；将分散体C进行热还原,并在该温度下老化,制得分散体D；反应结束后,将分散体D冷却至室温。加入乙醇提取产物,然后离心回收数次以去除残留试剂。本发明制备方法简单高效、成本低、可大规模生产,得到的磁性石墨烯具有良好的铁磁性能。该过程发生在密闭高压容器中,可以抑制组分挥发且高温条件有利于提高磁性。(The invention provides magnetic graphene and a preparation method thereof, wherein the preparation method comprises the following steps: adding graphene oxide into oleylamine and dibenzyl ether, and uniformly mixing to obtain a dispersion A; mixing Fe (acac) 3 Dissolving the mixture into the dispersion A, and uniformly dispersing the mixture by stirring/ultrasonic treatment to obtain a dispersion B; then transferring the obtained light brown dispersion B into a closed high-pressure container, and then flushing with nitrogen/argon to remove trace oxygen and moisture to obtain a dispersion C; thermally reducing the dispersion C and aging at the temperature to obtain a dispersion D; after the reaction was complete, dispersion D was cooled to room temperature. The product was extracted by adding ethanol and then recovered by centrifugation several times to remove residual reagent. The preparation method is simple and efficient, has low cost, can be used for large-scale production, and the obtained magnetic graphene has good ferromagnetic performance. The process takes place in a closed high pressure vessel, which can inhibit the volatilization of components and the high temperature condition is favorable for improving the magnetism.)

1. The preparation method of the magnetic graphene is characterized by comprising the following steps:

adding graphene oxide into a mixture of oleylamine and benzyl ether, and uniformly mixing to obtain a dispersion A;

mixing Fe (acac)₃Dissolving the mixture into the dispersoid A, and dispersing the mixture uniformly through pretreatment to obtain a dispersoid B;

transferring the dispersion B into a closed high-pressure container, and then flushing with inert gas to obtain a dispersion C;

carrying out thermal reduction and aging on the dispersion C to obtain a dispersion D;

dispersion D was cooled to room temperature and the product was extracted by addition of a volatile polar solvent.

2. The method for preparing magnetic graphene according to claim 1, wherein the mixing is performed by uniformly dispersing graphene oxide and a mixture of oleylamine and dibenzyl ether by mechanical stirring and/or ultrasonic treatment.

3. The method according to claim 1, wherein the pretreatment is a mechanical stirring and/or ultrasonic treatment of Fe (acac)₃And dispersion a was uniformly dispersed.

4. The method according to claim 1, further comprising centrifuging the extracted product.

5. The method according to claim 1, wherein the inert gas is nitrogen and/or argon.

6. The method for preparing magnetic graphene according to claim 1, wherein the temperature of the thermal reduction is 150 ℃ 250-^oAnd C, the aging temperature is the same as the thermal reduction temperature, and the aging time is 1.5-2.5 h.

7. The method according to claim 1, wherein the Fe (acac)₃The concentration of (B) is 0.3-6 mol/L.

8. The method according to claim 1, wherein the concentration of the graphene oxide dispersion is 1-10 mg/mL.

9. The method for preparing magnetic graphene according to claim 1, wherein the volatile polar solvent includes any one of ethanol, propanol and/or isopropanol.

10. A magnetic graphene prepared according to the preparation method of any one of claims 1 to 9.

Technical Field

The invention relates to magnetic graphene and a preparation method thereof, and belongs to the field of composite graphene materials.

Background

Graphene is a novel carbon nanomaterial, consisting of sp²The hybridized carbon atoms form a honeycomb lattice structure and have the characteristics of excellent photoelectric property, mechanical property, larger specific surface area, stronger adsorbability, good thermal stability and the like. The magnetic nano particles have the characteristics of magnetism and nano, have small-size effect, superparamagnetism, biocompatibility, surface effect and the like, but are easy to agglomerate to cause superparamagnetism loss.

Many researchers have incorporated magnetic metal oxides into graphene oxide-based nanocomposites, referred to as magnetic graphene. As a composite of magnetic nanoparticles and graphene, magnetic graphene has both excellent chemical and physical properties, such as paramagnetism, excellent specific surface area, strong chemical stability, size coordination, and biocompatibility. The magnetic graphene composite material has better functionality than single graphene or magnetic particles, and can make up for the respective defects of the two materials. In general, magnetic particles can improve the dispersibility of graphene in water; the huge surface area of graphene can load a large amount of magnetic nanoparticles, so that the magnetic nanoparticles are prevented from agglomerating, and meanwhile, new properties are endowed to the magnetic particles.

In the prior art, a solvothermal method is usually adopted for preparing the magnetic graphene, but the preparation cost is high, and the process is complex, so that the method is not suitable for mass production.

Disclosure of Invention

The invention aims to provide magnetic graphene and a preparation method thereof, and aims to solve the problems of high preparation cost, complex process and unsuitability for mass production in the prior art.

In order to solve the technical problems, the invention is realized by adopting the following technical scheme:

a preparation method of magnetic graphene comprises the following steps:

adding graphene oxide into a mixture of oleylamine and benzyl ether, and uniformly mixing to obtain a dispersion A;

mixing Fe (acac)₃Dissolving the mixture into the dispersoid A, and dispersing the mixture uniformly through pretreatment to obtain a dispersoid B;

transferring the dispersion B into a closed high-pressure container, and then flushing with inert gas to obtain a dispersion C;

carrying out thermal reduction and aging on the dispersion C to obtain a dispersion D;

dispersion D was cooled to room temperature and the product was extracted by addition of a volatile polar solvent.

Further, the mixing is to disperse the graphene oxide and the mixture of oleylamine and dibenzyl ether uniformly by mechanical stirring and/or ultrasonic treatment.

Further, the pretreatment is that Fe (acac) is mixed by mechanical stirring and/or ultrasonic treatment₃And dispersion a was uniformly dispersed.

Further, the method also comprises the step of carrying out centrifugal treatment on the extracted product.

Further, the inert gas is nitrogen and/or argon.

Further, the temperature of the thermal reduction is 150 ℃ to 250-^oC。

Furthermore, the aging temperature is the same as the thermal reduction temperature, and the aging time is 1.5-2.5 h.

Further, the Fe (acac)₃The concentration of (B) is 0.3-6 mol/L.

Further, the concentration of the graphene oxide dispersion liquid is 1-10 mg/mL.

Further, the volatile polar solvent comprises any one of ethanol, propanol and/or isopropanol.

The second purpose of the invention is to provide the magnetic graphene prepared by the preparation method.

Compared with the prior art, the invention has the following beneficial effects:

(1) the method has the advantages that the ferric acetylacetonate is used as a magnetic iron source and is blended with the graphene oxide, thermal reduction and aging are carried out in a closed high-pressure inert gas atmosphere, and then cooling and extraction are carried out, so that the preparation process is simple and efficient, and the used raw materials and reagents are low in acquisition difficulty and cost and are suitable for large-scale production;

(2) by controlling the thermal reduction temperature and the aging temperature and time and carrying out reaction in a high-pressure closed container, the method can inhibit component volatilization, is favorable for improving magnetism under high-temperature conditions, and can obtain magnetic graphene with good ferromagnetic property.

(3) The oleylamine and the dibenzyl ether are used as solvents, so that the graphene oxide can be dispersed more uniformly, and the adsorbed magnetic particles are prevented from being agglomerated to cause superparamagnetic loss.

Detailed Description

The invention is further described below. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

Example 1

100 parts by weight of graphene oxide was added to a mixture of 30 parts by weight of oleylamine and 35 parts by weight of dibenzyl ether, and the mixture was uniformly mixed to obtain dispersion a.

20 parts by weight of 0.3 mol/L Fe (acac)₃Dissolved in dispersion a, dispersed uniformly by mechanical agitation and sonication to give dispersion B, which was light brown in color.

The light brown dispersion B obtained was transferred to a closed high pressure vessel and then flushed with nitrogen to remove traces of oxygen and moisture to give dispersion C.

Thermally reducing the dispersion C at 150 ℃, and aging for 1.5 h at the temperature to obtain a dispersion D;

after the end of the aging, dispersion D was cooled to room temperature. And adding ethanol to extract the magnetic graphene in the dispersion D, and then centrifugally recovering to remove residual reagent to obtain the final product, namely the magnetic graphene.

Example 2

100 parts by weight of graphene oxide was added to a mixture of 30 parts by weight of oleylamine and 35 parts by weight of dibenzyl ether, and the mixture was uniformly mixed to obtain dispersion a.

20 parts by weight of 1.0 mol/L Fe (acac)₃Dissolved in dispersion a, dispersed uniformly by mechanical agitation and sonication to give dispersion B, which was light brown in color.

The light brown dispersion B obtained was transferred to a closed high pressure vessel and then flushed with nitrogen to remove traces of oxygen and moisture to give dispersion C.

Thermally reducing the dispersion C at 200 ℃, and aging for 2 h at the temperature to obtain a dispersion D;

after the end of the aging, dispersion D was cooled to room temperature. And adding propanol to extract the magnetic graphene in the dispersion D, and then centrifugally recovering to remove residual reagent to obtain the final product, namely the magnetic graphene.

Example 3

100 parts by weight of graphene oxide was added to a mixture of 30 parts by weight of oleylamine and 35 parts by weight of dibenzyl ether, and the mixture was uniformly mixed to obtain dispersion a.

20 parts by weight of 2.0 mol/L Fe (acac)₃Dissolved in dispersion a, dispersed uniformly by mechanical agitation and sonication to give dispersion B, which was light brown in color.

The light brown dispersion B obtained was transferred to a closed high pressure vessel and then flushed with nitrogen to remove traces of oxygen and moisture to give dispersion C.

Thermally reducing the dispersion C at 250 ℃, and aging for 2.5 h at the temperature to obtain a dispersion D;

after the end of the aging, dispersion D was cooled to room temperature. Adding isopropanol to extract the magnetic graphene in the dispersion D, and then centrifugally recycling to remove residual reagents to obtain the final product, namely the magnetic graphene.

Example 4

100 parts by weight of graphene oxide was added to a mixture of 30 parts by weight of oleylamine and 35 parts by weight of dibenzyl ether, and the mixture was uniformly mixed to obtain dispersion a.

20 parts by weight of 4.0 mol/L Fe (acac)₃Dissolved in dispersion a, dispersed uniformly by mechanical agitation and sonication to give dispersion B, which was light brown in color.

The light brown dispersion B obtained was transferred to a closed high pressure vessel and then flushed with argon to remove traces of oxygen and moisture to give dispersion C.

Thermally reducing the dispersion C at 200 ℃, and aging for 2 h at the temperature to obtain a dispersion D;

after the end of the aging, dispersion D was cooled to room temperature. And adding ethanol to extract the magnetic graphene in the dispersion D, and then centrifugally recovering to remove residual reagent to obtain the final product, namely the magnetic graphene.

Example 5

100 parts by weight of graphene oxide was added to a mixture of 30 parts by weight of oleylamine and 35 parts by weight of dibenzyl ether, and the mixture was uniformly mixed to obtain dispersion a.

20 parts by weight of 6.0 mol/L Fe (acac)₃Dissolving the mixture into the dispersion liquid of the dispersion A, and uniformly dispersing the mixture by mechanical stirring and ultrasonic treatment to obtain a dispersion B, wherein the color of the dispersion B is light brown.

The light brown dispersion B obtained was transferred to a closed high pressure vessel and then flushed with nitrogen to remove traces of oxygen and moisture to give dispersion C.

Thermally reducing the dispersion C at 200 ℃, and aging for 2 h at the temperature to obtain a dispersion D;

after the end of the aging, dispersion D was cooled to room temperature. And adding ethanol to extract the magnetic graphene in the dispersion D, and then centrifugally recovering to remove residual reagent to obtain the final product, namely the magnetic graphene.

Comparative example 1

In patent publication No. CN 109265744B, ferrous chloride tetrahydrate and ferric chloride hexahydrate are used as magnetic iron sources to prepare a magnetic graphene material.

The magnetic graphene prepared in examples 1 to 5 was subjected to a performance test, and the magnetic properties were measured by a dynamic hysteresis loop measuring instrument, with the results as follows:

example 1

Example 2

Example 3

Example 4

Example 5

Comparative example 1

Ferromagnetic property

25.6 emu/g

37.8 emu/g

35.2 emu/g

34.5 emu/g

34.2 emu/g

9.7 emu/g

As can be seen from the above table, the thermal reduction temperature and the aging temperature and time described in example 2, i.e., the thermal reduction temperature is 200 ℃, the aging time is 2 hours, and Fe (acac)₃When the concentration of (A) is 1 mol/L, the prepared magnetic graphene material has the highest ferromagnetic performance. From the aspect of ferromagnetic performance, compared with the preparation method of comparative example 1, the method provided by the invention adopts the mixture of oleylamine and dibenzyl ether as the solvent to dissolve graphene, so that the graphene is effectively dispersed uniformly, and the adsorbed magnetic particles are prevented from being agglomerated to cause superparamagnetic loss. In addition, as can be seen from comparison of examples 1, 2, 3, 4, 5 and 1, the ferromagnetic properties of the magnetic graphene material prepared according to the present invention are superior.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.