Method for preparing graphene

Abstract

A method for preparing graphene, which initially weakens the van der Waals force between graphite layers by means of laser cracking treatment, and then combines with the thin layer of graphite through a release agent whose molecules can be inserted between the graphite layers, and plays a role in exfoliating the graphite. , and then through the expansion and explosion of the bubbles, the bonding force between the graphite layers is weakened again to break the connection between the graphite layers, so that the mixture of graphite, graphene and exfoliating agent can be obtained, and finally the exfoliation is carried out by means of separation. After the agent is removed, graphene is extracted from the mixture of graphite and graphene by extraction, and the preparation of graphene is completed. The process is simple, the preparation efficiency is high, and the graphene purity is high. The preparation process is environmentally friendly and does not produce pollution.

Description

[0001] 【Technical field】 [0002] The invention belongs to the technical field of carbon materials, and in particular relates to a preparation method of graphene. [0003] 【Background technique】 [0004] Due to its unique structure and photoelectric properties, graphene has become a research hotspot in the fields of carbon materials, nanotechnology, condensed matter physics and functional materials. Graphene is a new type of nanomaterial with the thinnest, highest strength, and strongest electrical and thermal conductivity found so far. Graphene is called "black gold" and is the "king of new materials". Its theoretical specific surface area is as high as 2630m2 / g. It can be used in effect transistors, electrode materials, composite materials, liquid crystal display materials, sensors, etc. But the main problem encountered in the process of using graphene is that it cannot be mass-produced at present. [0005] At present, there are mainly two methods for the production and pre...

AI Technical Summary

Problems solved by technology

But the main problem encountered in the process of using graphene is that it cannot be mass-produced at present

[0005] At present, there are mainly two methods for the production and preparation of graphene. One method is the mechanical exfoliation method, which uses the friction and relative motion between the object and graphene to obtain a thin layer of graphene material, but this method The efficiency and purity of obtaining graphene are extremely low, and the result is very unsatisfactory; the second method is the redox method, which is to oxidize natural graphite by using chemical reagents such as sulfuric acid and nitric acid and oxidants such as potassium permanganate and hydrogen peroxide. Increase the distance between the graphite layers, insert oxides between the graphite layers to obtain graphite oxide, then wash the reactants with water, and dry the washed solids at low temperature to obtain graphite oxide powder. Then the graphite oxide powder is peeled off by physical exfoliation, high temperature expansion and other methods to obtain graphene oxide, and finally the graphene oxide is reduced by chemical method to obtain graphene

This method is simple to operate and high in yield, but the quality of the product is low, and the prepared graphene is prone to agglomeration and difficult to disperse. Due to the presence of van der Waals interaction, graphene with a high specific surface area tends to form irreversible agglomerates, and even re- Graphene is piled up to form graphite, which affects the mass production of graphene, and also limits its application

In addition, the reducing agent used in the chemical redox method is toxic and causes certain pollution to the environment.