阅读说明：本技术 一种氟化石墨烯材料的制备方法 (Preparation method of fluorinated graphene material ) 是由 冯奕钰 俞慧涛 高龙 唐俊稳 封伟 于 2019-03-28 设计创作，主要内容包括：本发明公开一种氟化石墨烯材料的制备方法,首先利用羧基化的方法将石墨烯进行功能化处理得到羧基化石墨烯,然后利用脱羧取代的方法,将石墨烯表面羧基上的羟基进行氟元素取代,得到氟化石墨烯。经表征分析,氟元素成功接枝在石墨烯表面,摩尔接枝率可达15％,而且氟化的石墨烯表面完整,未发生明显的结构破坏。该发明为氟化石墨烯提供了方法和应用前提。(The invention discloses a preparation method of a fluorinated graphene material, which comprises the steps of firstly carrying out functionalization treatment on graphene by utilizing a carboxylation method to obtain carboxylated graphene, and then carrying out fluorine element substitution on hydroxyl on carboxyl on the surface of the graphene by utilizing a decarboxylation substitution method to obtain the fluorinated graphene. Through characterization and analysis, the fluorine element is successfully grafted on the surface of the graphene, the molar grafting rate can reach 15%, and the fluorinated graphene has a complete surface and is not obviously structurally damaged. The invention provides a method and application premise for fluorinated graphene.)

1. The preparation method of the fluorinated graphene material is characterized by comprising the following steps of firstly, reacting graphene oxide, sodium hydroxide and sodium chloroacetate to convert hydrogen atoms of hydroxyl groups in the graphene oxide into carboxyl groups, so as to obtain carboxylated graphene; and then reacting the carboxylated graphene, a fluorine source substance and silver nitrate to replace hydroxyl in carboxyl in the carboxylated graphene by fluorine atoms to obtain the fluorinated graphene.

2. The method for preparing a fluorinated graphene material according to claim 1, wherein the molar ratio of sodium hydroxide to sodium chloroacetate is equal when graphene oxide, sodium hydroxide and sodium chloroacetate react.

3. The method for preparing a fluorinated graphene material according to claim 1, wherein when graphene oxide, sodium hydroxide and sodium chloroacetate are reacted, water is selected as a reaction atmosphere, stirring reaction is performed at room temperature of 20-25 ℃, and ultrasonic or mechanical stirring is selected.

4. The method of claim 1, wherein the reaction time of graphene oxide, sodium hydroxide and sodium chloroacetate is 6-15 hours, preferably 8-12 hours.

5. The method of claim 1, wherein the fluorine source is a commercially available fluorine-containing reagent, sodium fluoride reagent, or high purity fluorine gas.

6. The method according to claim 1, wherein when the carboxylated graphene, the fluorine source substance and the silver nitrate are reacted, the mass ratio of the carboxylated graphene to the fluorine source substance to the silver nitrate is 1: (3-8): 1, preferably 1: (5-8): 1.

7. the method according to claim 1, wherein when the carboxylated graphene, the fluorine source substance and the silver nitrate are reacted, water is selected as a reaction atmosphere, vacuum pumping is performed, an inert protective gas is filled, and a reflux reaction is performed at 80-90 ℃ for 20-24 hours.

8. The fluorinated graphene material obtained by the production method according to any one of claims 1 to 7, wherein fluorine is grafted to the surface of graphene in the form of a covalent bond.

9. The fluorinated graphene material of claim 8, wherein the fluorine atom is bonded to the graphene as "F — C (carbon atom of carbonyl) -O —".

10. The fluorinated graphene material of claim 8 or 9, wherein the molar grafting ratio is 10% to 15%.

Technical Field

The invention belongs to the field of carbon nano composite materials, and particularly relates to a preparation method of a fluorinated graphene material.

Background

Graphene is the most attractive new two-dimensional material discovered recently, and has acquired the 2010 nobel prize, and its excellent physical and chemical properties have led researchers to pay great attention to it today. Meanwhile, research products of various graphene are also greatly applied to scientific social life. The composite material taking GO as a substrate is a research angle for development and utilization of graphene, and particularly has a very wide application prospect in the fields of liquid crystal devices, photoelectric information storage, electronic devices, sensing materials, catalysts and the like.

The problem of dispersibility of graphene has been one of the topics of scientific interest, because graphene as an excellent carrier itself provides limited performance, and a functional group must be grafted to bring the scientific application of the new material into full play. Moreover, the quality of life of people is continuously improved, and the issues of energy storage, environmental friendliness and the like become more and more sensitive, so that the development of energy storage environment-friendly materials becomes very important. Through long-time research, the method for covalent bond functionalization is found to be capable of grafting the group with the fluorine element on the surface of the graphene, and shows higher energy storage density, better surface contact effect and the like. And the fluorinated graphene molecules can be subjected to composite treatment with various materials to obtain different types of graphene composite materials, such as fluorinated graphene/self-repairing polymer materials, fluorinated graphene/polypyrrole composite materials and the like. Therefore, the preparation method or the process for obtaining the fluorinated graphene has great potential in the aspects of energy storage, material corrosion prevention, aerospace equipment and the like.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, provides a preparation method of a fluorinated graphene material, and is used for polymer framework materials, battery anode and cathode materials, quantum dots and the like in the future, so that the preparation method has a wide application prospect.

The technical purpose of the invention is realized by the following technical scheme.

Firstly, reacting graphene oxide, sodium hydroxide and sodium chloroacetate to convert hydrogen atoms of hydroxyl groups in the graphene oxide into carboxyl groups, so as to obtain carboxylated graphene; and then reacting the carboxylated graphene, a fluorine source substance and silver nitrate to replace hydroxyl in carboxyl in the carboxylated graphene by fluorine atoms to obtain the fluorinated graphene.

In addition, the sodium hydroxide provides an alkaline environment for the reaction, enhances the hydrolysis, and reacts with the residual chloroacetic acid in the sodium chloroacetate to form corresponding salt, thereby avoiding the influence of the addition of other ions.

Further, sodium hydroxide and sodium chloroacetate were in equimolar ratio.

In addition, when graphene oxide, sodium hydroxide and sodium chloroacetate are reacted, water is selected as a reaction atmosphere, stirring reaction is carried out at room temperature of 20-25 ℃, and the reaction time is 6-15 hours, preferably 8-12 hours; stirring is carried out by selecting ultrasound or machinery.

And after obtaining the carboxylated graphene, centrifuging the product, washing the product twice by absolute ethyl alcohol, centrifuging the product, washing the product by deionized water, dialyzing the product in a dialysis bag, and drying the product at the temperature of 60-70 ℃.

Further, the fluorine source substance is a commercially available fluorine-containing reagent, sodium fluoride reagent or high-purity fluorine gas.

The mass ratio of the carboxylated graphene to the fluorine source substance to the silver nitrate is 1: (3-8): 1, preferably 1: (5-8): 1.

in addition, when the carboxylated graphene, the fluorine source substance and the silver nitrate react, water is selected as a reaction atmosphere, inert protective gas is filled after vacuum pumping, reflux reaction is carried out at 80-90 ℃, and the reaction time is 20-24 hours;

and after the reaction of the carboxylated graphene, the fluorine source substance and the silver nitrate is finished, cooling to room temperature, then carrying out suction filtration on the obtained solution, washing filter residues with deionized water and absolute ethyl alcohol, then putting the washed solution into a dialysis bag for dialysis, and carrying out freeze drying for 24 hours after 3-5 days (24 hours per day) of dialysis to obtain the fluorinated graphene.

In the finally prepared fluorinated graphene material, fluorine is grafted on the surface of graphene in a covalent bond mode, the molar grafting rate is 10-15%, and F-C (carbon atom of carbonyl) -O-graphene is adopted.

Compared with the prior art, the technical scheme of the invention is that firstly, the graphene is functionalized by using a carboxylation method to obtain the carboxylated graphene, and then, hydroxyl on the carboxyl on the surface of the graphene is substituted by fluorine element by using a decarboxylation substitution method to obtain the fluorinated graphene. Through characterization and analysis, the fluorine element is successfully grafted on the surface of the graphene, the molar grafting rate can reach 15%, and the fluorinated graphene has a complete surface and is not obviously structurally damaged. The invention provides a method and application premise for fluorinated graphene.

Drawings

Fig. 1 is an X-ray energy spectrum of fluorinated graphene; ultraviolet spectrograms of graphene oxide, carboxylated graphene and fluorinated graphene.

Fig. 2 is an infrared spectrum of graphene oxide, carboxylated graphene, and fluorinated graphene.

Fig. 3 is a scanning electron micrograph of fluorinated graphene prepared according to the present invention.

FIG. 4 is a schematic view of a specific process of the preparation method of the present invention.

Fig. 5 is a schematic diagram of a chemical formula structure of a fluorinated graphene material prepared according to the present invention.

Detailed Description

The following embodiments are further described in the present invention, but not intended to limit the scope of the invention. Drugs were purchased from alatin, llc.