| abstract |
A method of producing graphene sheets from coke or coal powder, comprising: (a) forming an intercalated coke or coal compound by electrochemical intercalation conducted in an intercalation reactor, which contains (i) a liquid solution electrolyte comprising an intercalating agent; (ii) a working electrode that contains the powder in ionic contact with the liquid electrolyte, wherein the coke or coal powder is selected from petroleum coke, coal-derived coke, meso-phase coke, synthetic coke, leonardite, lignite coal, or natural coal mineral powder; and (iii) a counter electrode in ionic contact with the electrolyte, and wherein a current is imposed upon the working electrode and the counter electrode for effecting electrochemical intercalation of the intercalating agent into the powder; and (b) exfoliating and separating graphene planes from the intercalated coke or coal compound using an ultrasonication, thermal shock exposure, mechanical shearing treatment, or a combination thereof to produce isolated graphene sheets. |