Method for preparing graphene by electrochemically expanding intercalated graphite

Abstract

The invention discloses a method for preparing graphene by electrochemically expanding intercalated graphite, wherein the method comprises the specific processes: adding intercalated graphite into molten paraffin, kneading, and pressing into an intercalated graphite electrode in a mold after uniformly kneading; taking the intercalated graphite electrode as a cathode, a graphite plate as an anode and an alkaline aqueous solution as an electrolyte solution, and applying 3-15 V direct-current voltage to prepare expanded graphite; and pickling the expanded graphite, ultrasonically stripping, and drying to obtain graphene powder. Compared with a hydrogen peroxide expansion process, the novel process for preparing graphene by electrochemically expanding intercalated graphite provided by the invention is higher in safety, lower in preparation cost and more stable and uniform in product quality, does not damage a lamellar structure of graphene, and is suitable for large-scale production.

Description

technical field [0001] The invention relates to the technical field of graphene, in particular to a method for preparing graphene by electrochemically expanding intercalated graphite. Background technique [0002] Since its discovery in 2004, graphene has attracted much attention as a new type of carbon material. It is a completely sp 2 The quasi-two-dimensional crystal material composed of hybrid carbon atoms with a thickness of only one atomic layer or several single atomic layers has excellent properties such as high light transmission and electrical conductivity, high specific surface area, high strength and flexibility, etc. It is expected to be widely used in the fields of high-performance nanoelectronic devices, optoelectronic devices, gas sensors, composite materials, field emission materials and energy storage. However, the low-cost and large-scale preparation of high-quality graphene still faces difficulties, which restricts the development and application of th...

AI Technical Summary

Problems solved by technology

[0005] 1. The principle of the expansion reaction between hydrogen peroxide or oxalic acid and intercalated graphite is that intercalant molecules catalyze the decomposition of hydrogen peroxide to generate oxygen, which expands the interlayer spacing of graphite, but the oxygen and oxygen free radicals generated during the reaction will oxidize graphite to a certain extent. As a result, the graphite sheet structure is destroyed, which affects the conductivity of the final graphene.

[0006] 2. The hydrogen peroxide decomposition process is accompanied by the generation of a large amount of heat and a large amount of oxygen at the same time. The reaction process is violent and has certain dangers.

[0007] 3. There is a large amount of ineffective decomposition in the catalytic decomposition process of hydrogen peroxide, resulting in low utilization rate of reaction raw materials, high energy consumption and high cost

[0008] 4. As the decomposition reaction continues to occur, the concentration of the hydrogen peroxide solution will continue to decrease, resulting in a decrease in the subsequent reaction rate and a longer overall reaction time. At the same time, due to changes in the expansion liquid system, the expansion degree of the intercalated graphite in the later stage of the reaction will not be enough to affect the quality of the final product. Quality Consistency

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