Preparation method of graphene oxide dispersion liquid

Abstract

The invention discloses a preparation method of a graphene oxide dispersion liquid, and the preparation method comprises the following steps: performing ultrasonic treatment so as to obtain a sulfate-intercalated graphite / sulfuric acid mixture; adding potassium permanganate into the obtained sulfate-intercalated graphite / sulfuric acid mixture for a medium-temperature oxidation reaction to obtain a preliminary graphite oxide; performing a high-temperature hydrolysis reaction to obtain a graphite oxide with a hydrophilic group; adding hydrogen peroxide and continuously performing an oxidation reaction to obtain luminous yellow graphite oxide turbid liquid; centrifuging or filtering to obtain claybank mud-like or cake-like object, and treating with a mixed solution of hydrogen peroxide and concentrated sulfuric acid to obtain graphite oxide with a great quantity of hydrophilic groups; washing and vacuum-drying to obtain pure graphite oxide, adding into a solvent and performing ultrasonic treatment to obtain graphene oxide dispersion liquid. The graphene oxide in the graphene oxide dispersion liquid has good dispersity, good stability and relatively large slice. By adopting the preparation method, the process steps are simplified, and the production cost and energy consumption are reduced; the emission of NO2 / N2O4 toxic gas is avoided in the reaction process, thereby being environment-friendly.

Description

technical field [0001] The invention belongs to the technical field of graphene oxide preparation, in particular to a method for preparing a graphene oxide dispersion liquid. Background technique [0002] It is generally believed that graphite oxide is a quasi-two-dimensional layered structure. During the oxidation process, graphene sheets are bonded with a large number of oxygen-containing functional groups such as hydroxyl, carboxyl, and epoxy groups. Due to the support of these functional groups and the water between the sheets, the lattice parameters of pristine graphite expand from 0.335 nm to 0.6-1.1 nm of graphite oxide (Lerf, A. et al. Physical Chemistry of Solids 67, 1106 (2006)), It is more conducive to the realization of single-sheet exfoliation and continuous preparation of graphene oxide; at the same time, the functional group also endows the graphene oxide sheet with excellent chemical activity and wetting properties, and makes its surface negatively charged, w...

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Problems solved by technology

In addition, it takes a long time for the obtained graphite oxide to be stripped into graphene oxide simply by ultrasonic treatment, generally 2-5h, and it is more difficult to realize stripping into single-layer graphene, and the resulting single-layer graphene has a smaller size. 0.1-10μm, the yield is also low, relative to multi-layer (2-10 layers) graphene oxide is 10-20%

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