Method for preparing graphene nano-sheet based on crystalline flake graphite

Abstract

The invention relates to the technical field of graphene nano-sheets, and discloses a method for preparing a graphene nano-sheet based on crystalline flake graphite. According to the preparation method, crystalline flake graphite serving as a raw material is oxidized by adopting low temperature, medium temperature and high temperature three stages, so that the side reaction in the graphite oxidizing process can be effectively controlled, and the graphite oxidizability can be improved; the graphite oxide is pre-stripped at a low temperature, which has lower cost in comparison with that for high-temperature stripping at about 1000 DEG C, and is applicable to industrial application. The ball mill method assisted with discharge plasma is adopted, the preparation method is simple in process andcan be produced in a large scale, has relatively small damage to graphite lamella, few-layer graphene nano-sheet with relatively good crystallinity can be easily obtained, and a good reduction effectcan be achieved for graphite by adding a solid-state ball mill medium, and the prepared graphene nano-sheet has high quality and a multi-fold translucent yarn structure.

Description

technical field [0001] The present invention relates to the technical field of graphene, more specifically, to a method for preparing graphene nanosheets based on flake graphite. Background technique [0002] Graphene is a two-dimensional planar single-layer structure of carbon formed by sp2 hybridized carbon atoms bonded in the form of a hexagonal lattice, which is an allotrope of carbon. Graphene is the basic unit for constructing other dimensional carbon materials. When it changes in the way of wrapping, winding and stacking, it can form zero-dimensional fullerene, one-dimensional carbon nanotube and three-dimensional graphite respectively. Graphene has good electrical and optical properties, mechanical properties, thermal conductivity and extremely high charge carrier mobility, as well as excellent mechanical strength and flexibility. These properties of graphene make it attract a lot of attention and quickly become a research hotspot. Graphene and its derivatives trea...

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Problems solved by technology

However, none of the above methods can be used to prepare defect-free high-quality graphene in large quantities.

For example, although the mechanical exfoliation method can theoretically produce defect-free high-quality graphene, the yield of the resulting graphene is very limited

Although the vapor deposition method can be used to prepare large-area graphene, its production process is complicated, the preparation conditions are harsh, the production cost is high, and the separation and transfer process of graphene film is very difficult, so this method still has great potential. limitation

[0003] The mechanical ball milling method is not only simple to operate, economical and applicable, but also easy to apply to large-scale industrial production. Therefore, it has also become a new process for the large-scale preparation of few-layer graphene nanosheets and their composite materials. However, by traditional solid phase The wet ball milling process developed by ball milling has a low yield of graphene, and solid medium mechanical ball milling easily leads to amorphization

The thickness of graphite flakes obtained by traditional shimmy high-energy ball milling is relatively thick, and due to the action of mechanical stress, it is difficult to preserve the integrity of the lamellar structure, and it is easy to form an edge carbon vacancy structure

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