Method for preparing multilayer graphene by low-temperature molten salt

Abstract

The invention discloses a method for preparing multilayer graphene by low-temperature molten salt. The method includes the steps: S1 sequentially cleaning, filtering and drying natural graphite, and then uniformly mixing the dried graphite with lithium carbonate and ammonium nitrate to obtain mixed raw materials; S2 placing the mixed raw materials into a high-temperature-resistant vessel, performing low-temperature reaction for 2-5 hours, performing high-temperature reaction on the mixed raw materials after low-temperature reaction for 2-20 minutes, and cooling the mixed raw materials to roomtemperature to obtain expanded graphite; S3 adding deionized water into the expanded graphite cooled to the room temperature, uniformly stirring the deionized water and the expanded graphite to obtainslurry, and then placing the slurry into a ball mill tank for ball-milling; S4 sequentially centrifugally separating, cleaning and freeze-drying the ball-milled slurry to obtain the multilayer graphene. The technological process for preparing graphene by a traditional oxidation-reduction method is improved, the method is environmentally friendly and good in safety, and corrosion of equipment caused by reactants can be reduced.

Description

technical field [0001] The invention belongs to the technical field of graphene preparation, and in particular relates to a method for preparing multilayer graphene with low-temperature molten salt. Background technique [0002] Graphene is a two-dimensional carbon nanomaterial in which carbon atoms form a hexagonal honeycomb lattice with sp² hybrid orbitals. Graphene has excellent optical, electrical, and mechanical properties, and has important application prospects in materials science, micro-nano processing, energy, biomedicine, and drug delivery, and is considered to be a revolutionary material in the future. [0003] Graphene has been exposed to scientific research as early as the 20th century, and graphene was prepared by tape separation method in 2004 by researchers from the University of Manchester and the Chernogolovka Institute of Microelectronics Technology. After years of development, the existing graphene preparation technologies mainly include mechanical exfo...

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Problems solved by technology

However, although the mechanical exfoliation method can prepare micron-sized graphene, its controllability is low, it is difficult to achieve large-scale synthesis, and it is not conducive to industrial mass production; graphene prepared by chemical vapor deposition has the characteristics of large area and high quality. But the cost is high at this stage, and the process conditions need to be further improved; the redox method has the advantages of low cost and simple operation, but the traditional redox method needs to consume a large amount of acid and lye that pollute the environment, and will also Corrosion of equipment, uncontrollable heat generated by the reaction, and potential explosion hazard

[0004] The patent with the application number CN201410317776.6 discloses a method for preparing graphene in large quantities by ball milling graphite oxide and magnesium powder. The method utilizes the Hummer method to process natural graphite to obtain graphite oxide, and then finally obtains graphite oxide by ball milling a mixture of graphite oxide and magnesium powder. Graphene has the characteristics of high specific capacitance, high rate characteristics, and long-term cycle stability. However, a large amount of concentrated sulfuric acid, hydrochloric acid, and hydrogen peroxide are used in the preparation process of this graphene, and a large amount of environmentally polluting pollutants are easily produced during the production process. Acid liquid not only easily corrodes the equipment, but also generates uncontrollable heat, which has a potential explosion hazard and reduces the safety of operators

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