Continuous Electrochemical Exfoliation of Micrometer-Sized Graphene Using Synergistic Ion Intercalations and Organic Solvents

A novel top-down electrochemical method is demonstrated to prepare gram quantities of few-layer graphene in a single-step, one-pot process. Potential-controlled cathodic reduction is used to intercalate graphite electrodes with alkali-substituted, ammonium- and dimethyl sulfoxide-solvated cations. In situ decomposition of the intercalated compounds breaks the pi-pi stacking of the graphene layers along the c axis of the graphite gallery, producing 1-20-mu m-diameter few-layer graphene sheets, without the need for defect-inducing oxidative or sonication treatments. With a slight modification of the electrodes' configuration, the process can run in a continuous manner, presenting a potentially scalable approach for few-layer graphene production.