Methods of forming graphene by graphite exfoliation
AssigneeNational University of Singapore
InventorsKian Ping Loh, Junzhong Wang
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Abstract
Methods of forming graphene by graphite exfoliation, wherein the methods include: providing a graphite sample having atomic layers of carbon; introducing a salt and a solvent into the space between the atomic layers; expanding the space between the atomic layers using organic molecules and ions from the solvent and the salt; and separating the atomic layers using a driving force to form one or more sheets of graphene; the graphene produced by the methods can be used to form solar cells, to perform DNA analysis, and for other electrical, optical and biological applications.
Claims23
A method of forming graphene, comprising:
- providing a graphite sample having atomic layers of carbon with spaces in between;
- immersing the graphite sample in an electrolytic solution of propylene carbonate and lithium perchlorate;
- performing electrolysis on the immersed graphite sample to introduce organic complexes of lithium ions and propylene carbonate into the spaces between the atomic layers to form intercalated graphite;
- subjecting the intercalated graphite to a thermal treatment that expands the space between the atomic layers to form expanded graphite;
- and
- separating the atomic layers using sonication to form one or more sheets of graphene.
A method of forming graphene from a graphite sample comprising a lattice of carbon atoms that define atomic layers and a layer spacing, comprising:
- intercalating propylene carbonate and lithium perchlorate into the carbon atom lattice via direct-current electrolysis of a 30 to 50 mg/ml solution of the lithium perchlorate in the propylene carbonate at a voltage of 15V+/−5V to form intercalated graphite;
- expanding the layer spacing by subjecting the intercalated graphite to a thermal process to form expanded graphite;
- and
- mechanically exfoliating one or more carbon atomic layers from the expanded graphite to form the graphene.
Dependencies are inferred from the claim text.