Method and device for preparing graphene oxide

Abstract

The invention relates to the field of preparation of graphene oxide, in particular to a method for preparing graphene oxide. The method comprises the following steps of adding graphite, acid and an oxidant into a material mixing kettle, mixing at low temperature, sending into a first pipeline reactor, and performing oxidizing reaction; adding a solvent and a reducing agent, uniformly mixing, sending into a second pipeline reactor, dispersing and reducing, and performing post-treatment, so as to obtain the graphene oxide. The method has the advantages that the material mixing and reaction types are controlled by pipelines, so that the defect of one-pot boiling type of the traditional kettle type reactor is overcome; the production process is safe and efficient, the product quality is more stable, the continuity of the material in the reaction process is guaranteed, the materials are uniformly mixed, and the utilization rate of the oxidant of potassium permanganate is higher; the oxidizing degree of a product is higher, and the method is suitable for industrialized production.

Description

technical field [0001] The invention relates to the field of graphene oxide preparation, in particular to a method and device for preparing graphene oxide. Background technique [0002] Graphene is a new type of carbon material with a two-dimensional honeycomb lattice structure formed by stacking a single layer of carbon atoms. Because of its high specific surface area (2600m 2 / g), high thermal conductivity (4800~5300W / (m K)) and high electron mobility (15000cm 2 / (V·s)) and other properties, it has a wide range of applications in the fields of composite materials, energy storage materials and solar cells. [0003] The macro-preparation of graphene is a prerequisite for realizing its many applications. At present, the preparation of graphene mainly includes the following methods: 1) chemical vapor deposition method; 2) micromechanical graphite exfoliation method; 3) metal surface epitaxy method; 4) redox method, etc. Among them, the redox method is currently the most co...

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Problems solved by technology

[0004] Due to the natural inertness of graphite, its oxidation process must be completed in a relatively harsh chemical environment, mainly including the following four methods: 1) Brodie method: this method uses fuming nitric acid and potassium chlorate as strong acid and strong oxidant, and it is necessary to repeat oxidation steps. Improve oxidation degree, and the use of potassium chlorate also has certain danger in addition; 2) Staudenmaier method: this method utilizes the mixed acid system that vitriol oil and fuming nitric acid are formed to react, is strong oxidizing agent with potassium chlorate, and oxidation degree can be controlled by stirring time, but This method seriously destroys the carbon layer of graphene oxide, and the use of potassium chlorate also has certain danger; 3) Hummers method: this method adopts concentrated sulfuric acid and sodium nitrate system, with potassium permanganate as strong oxidant, the product oxidation High degree, regular structure and easy to swell in water and delamination to obtain single-layer graphene oxide, but the use of sodium nitrate will produce toxic nitrogen oxides, polluting the environment; 4) Improved Hummers method: Kovtyukhova research group graphite Preoxidation is carried out in the concentrated sulfuric acid solution of potassium sulfate and phosphorus pentoxide, and then oxidized with potassium permanganate. The use of sodium nitrate in the reaction process can avoid the generation of nitrogen oxides, and the product oxidation degree is also high, but the waste produced More acid, more cumbersome to operate

In CN103382028A, a kind of method for preparing graphene oxide with concentrated sulfuric acid and potassium permanganate as strong acid and strong oxidizing agent has been announced, but highly active manganese heptoxide can be produced after the concentrated sulfuric acid and potassium permanganate are mixed. This kind of reaction in the tank reactor needs to strictly control the reaction temperature, otherwise it is easy to cause safety accidents

In addition, there are still disadvantages in the preparation of graphene oxide by kettle reaction, such as uneven stirring of materials, low utilization rate of potassium permanganate, temperature control to prevent material flushing, but too low reaction temperature is not conducive to rapid reaction, etc.

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