Method for electrochemically preparing graphene

Abstract

The invention discloses a method for electrochemically preparing graphene, which preferably comprises the steps of pressing a high-purity graphite raw material to form a graphite electrode, carrying out anodization through the graphite electrode by using sulfuric acid aqueous solution or acetic acid and the like mixed acid solution as an electrolyte to prepare a graphite intercalation product, and obtaining expanded graphite by high temperature or microwave and other methods; and then pressing the expanded graphite to prepare a reaction electrode, and carrying out secondary electrochemical intercalation and expansion to finally obtain laminar graphene. According to the invention, in the preparing process, potassium permanganate and other strong oxidizers are not used, and the damage of the strong oxidizers to the structure and performance of graphene are avoided; alkali metal, fuming sulfuric acid oxydol and other inflammable and explosive dangerous substances are not used, and toxic or harmful substances are not introduced, so that the production is safe and environment friendly; and at the same time, the method is simple in process flow, easy to operate, low in cost, high in yield, mild in reaction conditions and low in energy consumption, and is suitable for industrialized large-scale production.

Description

technical field [0001] The invention relates to a method for preparing graphene materials, in particular to a method for electrochemically preparing graphene, which belongs to the field of material technology. Background technique [0002] Graphene is another major discovery in the field of carbon materials after fullerene and carbon nanotubes. Graphene is composed of single layer sp 2 The honeycomb-like hexagonal planar two-dimensional crystal formed by the arrangement of hybridized carbon atoms can be stacked into 3D graphite, curled into 1D carbon nanotubes, or even wrapped into 0D fullerene. On a two-dimensional plane, sp 2 The hybridized carbon atoms are connected to the adjacent three carbon atoms through strong σ bonds, and the remaining P electron orbitals are perpendicular to the graphene plane, forming large π bonds with the surrounding atoms, making graphene have good conductivity. The theoretical specific surface area of ​​graphene can reach 2630 m 2 / g. The...

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Problems solved by technology

Among them, although the mechanical exfoliation method can obtain high-quality graphene, it cannot be used for large-scale production and cannot meet the needs of industrialization; although the graphite oxide reduction method can prepare a large amount of graphene at a relatively low cost, graphene The electronic structure and the integrity of the crystal are severely damaged by strong oxidants, which affect its electronic properties, which limits its application in devices to a certain extent.

Although the chemical deposition method can produce graphene with large area and excellent performance, the immaturity of the current process and the high cost limit its large-scale application.

In the international cutting-edge research, the preparation of graphene by electrochemical method has attracted sufficient attention in recent years. This method does not need to use strong oxidants such as potassium permanganate in the preparation process, which can avoid the damage of strong oxidants to the structure and properties of graphene; Use alkali metals (K, Na) and other flammable and explosive dangerous substances, do not introduce toxic and harmful substances, and are environmentally friendly; the preparation conditions are controllable; the cost is low, and it is suitable for large-scale production. However, graphite prepared by existing electrochemical methods The graphene sheet layer is thick, and the graphene structure made from commercial graphite electrode raw materials has many structural defects, which cannot meet the needs of practical applications well.

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