A method for large-scale clean preparation of graphene

Abstract

Provided is a large-scale clean preparation method for graphene, comprising: (i) preparing graphite raw material, water, foaming agent and surfactant into a suspension and stirring the suspension at a rotating speed of 300-500rpm to disperse the graphite raw material uniformly to obtain a dispersed suspension; (ii) feeding the dispersed suspension into a feed inlet (1) of a spraying device, the feed inlet communicating with a conveying chamber (2), the conveying chamber being internally provided with at least one ultrasonic probe (5); the dispersed suspension being subjected to ultrasonic treatment so that the foaming agent enters layers of graphite; the conveying chamber being internally provided with at least one air compressor (4) for pressurizing the dispersed suspension to accelerate the dispersed suspension to flow forward; the conveying chamber communicating with a drying chamber (3), and the dispersed suspension after treatment flowing into the drying chamber; and (iii) arranging a gas heating nozzle and at least one nozzle (7) at the top of the drying chamber; the dispersed suspension flowing through the nozzle and entering the drying chamber to be atomized by heated gas; the foaming agent being decomposed by heat so that interlayer spacing of graphite is increased; and after atomization and foaming, obtaining the graphene stripped off under a high-speed air flow. Preferably, at least one ultrasonic probe (6) is arranged at the nozzle. According to the method, two processes, i.e., mechanical stripping and drying, are integrated into a spray dryer and an ultrasonic device is arranged at the nozzle, thus providing graphite with a higher energy, increase the intercalating probability and improving the intercalating effect of the foaming agent. Hence, product quality is ensured and, environmental protection and no-pollution are achieved.

Description

technical field [0001] The invention relates to a method for preparing graphene, in particular to a large-scale clean preparation method for graphene. Background technique [0002] In 2004, two scientists from the University of Manchester in the United Kingdom discovered graphene using the method of micromechanical exfoliation, and won the Nobel Prize in Physics in 2010. Graphene is a planar structure material composed of single-atom-thick carbon atoms combined by sp2 bonds. The carbon-carbon bond length is about 0.142nm. There are three σ bonds in each lattice. The p orbitals of all carbon atoms Both are perpendicular to the sp² hybridization plane, and form a delocalized π bond throughout the graphene in a side-by-side manner. Theoretically, this has a perfect hexagonal network structure, showing excellent electronic stability, thermal conductivity, optical properties, and mechanical properties. Since the discovery of graphene, due to its excellent performance and huge m...

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Problems solved by technology

Moreover, if a strong oxidant is used to treat graphite, polar groups will be grafted on the surface of the prepared graphene, which will endanger human health and cause environmental pollution, destroy the lattice integrity of graphene, and reduce the electrical conductivity of the system.

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