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.