Simple thermal expansion method for preparing thin graphene

Abstract

The invention discloses a simple thermal expansion method for preparing thin graphene. The method comprises the following step: scattering graphite oxide powder into a furnace body of 250-400 DEG C to suddenly raise the temperature of the graphite oxide powder, so as to expand graphite oxide to obtain the thin graphene powder. The thermal expansion process of graphite oxide is directly completed under a simple condition without additional conditions mentioned in known reports such as graphite oxide pre-treatment, expansion in a hydrogen environment, expansion in a vacuum environment and the like. The number of laminates of graphene is less than 10, and graphene has no obvious diffraction peaks in an x-ray diffraction spectrum and belongs to short-range order and long-range disorder. The production cost is lowered while the production efficiency is improved, and the method is quite suitable for large-scaled production of graphene.

Description

technical field [0001] The invention relates to a simple thermal expansion preparation process of thin-layer graphene, in particular to a simple thermal expansion method for preparing thin-layer graphene; it belongs to the field of inorganic new energy materials. Background technique [0002] Graphene is composed of sp with hexagonal structure 2 A two-dimensional single-layer film composed of hybrid carbon atoms, there are two kinds of bonds in the graphene sheet: σ c-c bond and π bond. σ c-c The bonds exist on the two-dimensional plane of graphene, and because of its strongest bond energy, it has a good rigid structure. The π bond exists outside the two-dimensional plane of graphene, and is formed by the superposition of p electron orbitals perpendicular to the plane. The presence of such delocalized large π-bonds is beneficial to its electronic conductivity and provides a weaker force between graphene sheets. From a chemical point of view, structure determines propert...

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Problems solved by technology

[0005] Part of the process requires additional treatment of graphite oxide before graphite oxide expands, such as the process described in J Mater Chem C, 2013, 1, 50-53. Before the preparation of graphene, graphite oxide needs to be washed and pre-washed with hydrochloric acid. Treatment, using the residual hydrogen chloride to increase the internal pressure of expansion, so as to achieve the successful expansion of graphite oxide, so that the steps are more complicated, time-consuming, low in efficiency and high in cost, which seriously restricts the mass production of graphene; J Mater Sci 2014,49,4989 The process of -4997 is that before the preparation of graphene, graphite oxide needs to be freeze-dried to reduce the force between graphite oxides and make it easier to expand. However, the efficiency of freeze-drying is extremely low, and it is only suitable for laboratories. Research, it is difficult to scale up the process, which restricts the large-scale production of graphene in terms of cost and production efficiency

[0006] Another part of the process is harsh conditions for thermal expansion of graphite oxide, such as Chinese patent 200810151807.X, ACS Nano, 2009, 3, 3730-3736 and J Mater Chem 2011, 21, 5392-5397. In the process of thermal expansion, a relatively high negative pressure environment is required to achieve the successful expansion of graphite oxide. The conditions are relatively harsh and the requirements for equipment are extremely high, which invisibly increases the cost of equipment, making it difficult to scale up, and also restricts the large-scale production of graphene; The process reported in J Mater Chem 2010, 20, 8467-8469 is that in the preparation of graphene, a hydrogen environment is required, so that graphite oxide and hydrogen react violently to realize the expansion of graphite oxide. In this way, the process can be enlarged more Dangerous, requires specific equipment, and faces similar problems to the first type;

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