A kind of preparation method of graphene

Abstract

The invention discloses a preparation method of graphene, which is characterized in that natural graphite used as a raw material is subjected to mechanical stripping under the auxiliary action of graphene quantum dots by using a polar solvent as a dispersion medium to prepare the high-quality graphene. The stripping of the natural graphite and dispersion of the graphene nanosheets in the polar solvent are promoted by utilizing the favorable dispersivity of the graphene quantum dots in the polar solvent and the strong non-covalent bond combination between the graphene quantum dots and graphene / graphene laminae, thereby obtaining the high-quality graphene. According to the invention, the graphene powder is directly obtained from the natural graphite under the condition of not introducing any surfactant, inorganic salt, organic salt or any other impurity. Compared with the existing methods, the method is simple in technique, and can be perform in multiple polar solvents; the maximum yield of the obtained graphene can reach 50%, and the quality is good; the graphene quantum dots used for auxiliary stripping can be recycled; and thus, the method is very suitable for mass preparation of graphene.

Description

technical field [0001] The invention relates to a preparation method of graphene, which belongs to the technical field of new nanometer materials. Background technique [0002] Graphene is a nano-carbon material with a hexagonal lattice honeycomb structure formed by sp2 hybridization of a single layer of carbon atoms, which belongs to a new type of two-dimensional crystal material. Graphene has good electrical conductivity, thermal conductivity, optical transparency, and special mechanical and electronic properties. It has good application prospects in energy storage, transparent conductive devices, composite materials, and optoelectronic devices. Therefore, graphene has become a research hotspot in many disciplines such as materials science, physics and chemistry. [0003] The preparation methods of graphene mainly include mechanical exfoliation method, chemical vapor deposition method, oxidation intercalation re-reduction method and liquid phase exfoliation method. Among...

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Problems solved by technology

However, studies have shown that the yield of graphene prepared by the solvent stripping method has a great relationship with the solvent. Generally, N-2-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF) and other high-boiling point solvents are selected. Organic solvents, there is a problem that it is difficult to remove residual solvents

In addition, even if a suitable solvent is selected, the yield of simple solvent stripping is generally very low, further improving the stripping yield requires adding inorganic salts, alkalis or surfactants, etc., and there is also the problem of impurity removal.

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