CN113493200A

CN113493200A - Preparation method of graphene oxide

Info

Publication number: CN113493200A
Application number: CN202011113154.3A
Authority: CN
Inventors: 董雷; 杨悦琪
Original assignee: Suzhou North America High School
Current assignee: Suzhou North America High School
Priority date: 2020-10-17
Filing date: 2020-10-17
Publication date: 2021-10-12

Abstract

The invention relates to a preparation method of graphene oxide, which is characterized in that corundum-phase alumina is used for catalyzing and oxidizing graphite at a high temperature of more than 1000 ℃ in an air atmosphere for a short time to obtain the graphene oxide. Compared with the prior art, the invention provides a scheme for preparing graphene oxide by a solid phase method without using any strong acid.

Description

Preparation method of graphene oxide

Technical Field

The invention belongs to the technical field of new material preparation, and particularly relates to a preparation technology of graphene oxide.

Background

Graphene is a two-dimensional nanomaterial of a carbon monoatomic layer, and since the graphene is discovered in 2004, the graphene is paid unprecedented attention and is known as the king of materials. The preparation method of graphene can be divided into a top-down method and a bottom-up method, wherein the top-down method uses graphite as a raw material, the graphite is a crystalline carbon material and belongs to a layered structure, one graphite particle is like a book, and each piece of paper forming the book is a monoatomic layer of carbon, namely graphene. If the paper is wrapped, the carbon nano tube can be obtained, if the paper is wrapped skillfully, the carbon nano tube can be fullerene, and if the paper is of a three-dimensional structure instead of a single-layer structure, the carbon nano tube can be diamond, so that the graphene can be regarded as single-layer diamond. The method for preparing graphene from top to bottom is a process of how to tear open the book of graphite to obtain graphene sheets. The above process of preparing graphene is generally a process of forming a film using a carbon precursor.

Over the past decade, researchers around the world have developed various laboratory methods for preparing graphene, such as mechanical exfoliation, chemical vapor deposition, thermal decomposition of silicon carbide, and redox, with redox being the most prevalent of the most popular methods for industrialization. The oxidation-reduction comprises two steps of oxidation and reduction, wherein the first step of oxidation is to obtain graphene oxide, the preparation method of the graphene oxide is generally three, namely, a Standmaier method, a Brodies method and a Hummers method, and the basic principle of the preparation is that graphite is treated by strong protonic acid to form a graphite interlayer compound, and then a strong oxidant is added for oxidation. The use of strong acids can corrode equipment and cause severe contamination. After obtaining the graphene oxide, obtaining the graphene by a second reduction method, wherein the reduction method may be light reduction, thermal reduction, microwave reduction, chemical liquid phase reduction, and the like.

Disclosure of Invention

The invention aims to solve the problem of using strong acid in the most common method for preparing graphene by a redox method, the technical scheme for solving the problem is to directly utilize graphite to prepare graphene oxide by high-temperature catalytic oxidation of corundum-phase alumina in an air atmosphere, and the second aim of the invention is to provide a catalyst corundum-phase alumina for catalyzing graphite oxide in the air atmosphere.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a preparation method of graphene oxide and a catalyst for catalyzing graphite oxide are characterized by comprising the following steps:

uniformly mixing 5-20 wt% of flake graphite powder and 80-95 wt% of corundum phase alumina powder, placing the mixed powder in an air atmosphere muffle furnace at 1000-1300 ℃, preserving heat for 10-40 min, taking out the mixed powder at a high temperature, naturally cooling or water cooling to obtain yellow graphite oxide coated corundum powder, adding the yellow graphite oxide powder into water or absolute ethyl alcohol, placing the mixture in a planetary ball mill, performing wet ball milling for 10-24 hours, and performing centrifugal separation and drying to obtain graphene oxide.

The mass percentage of the flake graphite is 5-20 wt%, the percentage is too low, the yield is not high, and the oxidation loss of the graphite is serious when the percentage is too high.

The graphite oxidation temperature of the invention is 1000-1300 ℃, the temperature is too slow to be oxidized, and the temperature is too fast to be oxidized. Table 1 shows the yields of graphite oxide catalyzed by different oxides.

It is understood from Table 1 that the corundum phase alumina has the highest catalytic activity, and that corundum phase alumina as a catalyst can be repeatedly used.

Drawings

FIG. 1: TEM (transmission electron microscope) image 2 of graphene oxide after high temperature oxidation at 1000 ℃ and centrifugal separation: TEM (transmission electron microscope) image 3 of graphene oxide after high temperature oxidation at 1100 ℃ and centrifugal separation: TEM (transmission electron microscope) image of graphene oxide after 1200 ℃ high temperature oxidation and centrifugation 4: TEM (transmission electron microscope) image of graphene oxide after 1300 ℃ high-temperature oxidation and centrifugal separation

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

Example 1

Uniformly mixing 5 g of flake graphite powder and 95 g of corundum phase alumina powder, pouring the mixed powder into a flat-bottom corundum porcelain boat for paving, heating a muffle furnace to 1000 ℃ for heat preservation, opening a furnace door, rapidly putting the corundum porcelain boat into the muffle furnace, closing the furnace door for heat preservation for 30 minutes, taking out at high temperature for cooling, adding water into the cooled powder, putting the powder into a planetary ball mill, and performing ball milling for 24 hours, wherein a ball milling medium is agate balls. Placing the mixed solution after ball milling in a centrifuge at 2000 rpm, centrifuging for 5 minutes, drying the upper liquid to obtain graphene oxide powder, wherein the transmission electron microscope image of the powder is shown in figure 1.

Example 2

Mixing 10 g of flake graphite powder and 90 g of corundum phase alumina powder uniformly, pouring the mixed powder into a flat-bottom corundum porcelain boat for paving, heating a muffle furnace to 1100 ℃ for heat preservation, opening a furnace door, rapidly putting the corundum porcelain boat into the muffle furnace, closing the furnace door for heat preservation for 20 minutes, taking out at high temperature for cooling, adding water into the cooled powder, putting the powder into a planetary ball mill, and performing ball milling for 20 hours, wherein a ball milling medium is agate balls. Placing the mixed solution after ball milling in a centrifuge at 2000 rpm, centrifuging for 5 minutes, drying the upper liquid to obtain graphene oxide powder, wherein the transmission electron microscope image of the powder is shown in figure 2.

Example 3

Mixing 15 g of flake graphite powder and 85 g of corundum phase alumina powder uniformly, pouring the mixed powder into a flat-bottom corundum porcelain boat for paving, heating a muffle furnace to 1200 ℃ for heat preservation, opening a furnace door, rapidly putting the corundum porcelain boat into the muffle furnace, closing the furnace door for heat preservation for 15 minutes, taking out at high temperature for cooling, adding water into the cooled powder, putting the powder into a planetary ball mill, and performing ball milling for 15 hours, wherein a ball milling medium is agate balls. Placing the mixed solution after ball milling in a centrifuge at 2000 rpm, centrifuging for 5 minutes, drying the upper liquid to obtain graphene oxide powder, wherein the transmission electron microscope image of the powder is shown in figure 3.

Example 4

Uniformly mixing 20 g of flake graphite powder and 80 g of corundum phase alumina powder, pouring the mixed powder into a flat-bottom corundum porcelain boat for paving, heating a muffle furnace to 1300 ℃ for heat preservation, opening a furnace door, rapidly putting the corundum porcelain boat into the muffle furnace, closing the furnace door for heat preservation for 10 minutes, taking out at high temperature for cooling, adding water into the cooled powder, putting the powder into a planetary ball mill, and performing ball milling for 10 hours, wherein a ball milling medium is agate balls. Placing the mixed solution after ball milling in a centrifuge at 2000 rpm, centrifuging for 5 minutes, drying the upper liquid to obtain graphene oxide powder, wherein the transmission electron microscope image of the powder is shown in figure 4.

Claims

1. A preparation method of graphene oxide is characterized by comprising the following steps:

the method comprises the following steps: uniformly mixing 5-20 wt% of flake graphite powder and 80-95 wt% of corundum phase alumina powder;

step two: directly placing the mixed powder in an air atmosphere muffle furnace at the temperature of 1000-1300 ℃, and preserving heat for 10-40 min;

step three: directly taking out mixed powder of graphite and corundum phase alumina at the high temperature of 1000-1300 ℃, and naturally cooling or water cooling to obtain yellow graphite oxide coated corundum powder;

step four: and adding the yellow powder prepared in the third step into water or absolute ethyl alcohol, placing the mixture into a planetary ball mill for wet ball milling for 10-24 hours, and performing centrifugal separation and drying to obtain the graphene oxide.

2. The method for producing graphene oxide according to claim 1, characterized in that: the mass of the crystalline flake graphite powder accounts for 8-15 wt% preferably.

3. The method for producing graphene oxide according to claim 1, characterized in that: the weight percentage of the crystalline flake graphite powder is preferably 12-15 wt%.

4. The method for preparing graphene oxide according to claim 1, comprising the steps of:

the method comprises the following steps: uniformly mixing 15 wt% of flake graphite powder and 85 wt% of corundum phase alumina powder;

step two: directly placing the mixed powder in a muffle furnace with an air atmosphere at 1200 ℃, and preserving heat for 15 min;

step three: directly taking out the mixture obtained in the step two at a high temperature of 1200 ℃, and naturally cooling to obtain yellow graphite oxide coated corundum powder;

step four: and D, adding the yellow powder prepared in the step three into absolute ethyl alcohol, placing the mixture into a planetary ball mill for wet ball milling for 15 hours, centrifugally separating the mixture for 5 minutes, removing the upper liquid and drying the upper liquid to obtain the graphene oxide.

5. The method for preparing graphene oxide according to any one of claims 1 to 4, wherein: the mass of the corundum-phase alumina powder accounts for preferably 85-95 wt%.