Liquid-phase exfoliation of graphite for mass production of pristine few-layer graphene

Abstract

The science of graphene has bloomed in the last decade following its isolation. A promising future for this astonishing material is envisaged, with applications in printable and flexible electronics, solar cells and supercapacitors. Mass production of processable, high-quality graphene is of paramount importance if these commercial applications are to be realized. Among the emerging protocols for graphene preparation, liquid-phase exfoliation of pristine graphite holds particular promise owing to its low cost, simplicity, high throughput and potential industrial scalability. This review highlights recent progress in this regard. First, current exfoliation techniques including ultrasonication, shear force and supercritical fluid are discussed, then, we emphasize the advances in exfoliation and dispersion of graphene in water and organic solvents using different surfactants, polymers and other stabilizers. Dispersion efficiency in terms of yield, fraction of monolayers and graphene concentration as well as possible mechanisms for graphene stabilization are discussed. The advantages and challenges of those preparation procedures are examined. Finally, experimental results and theoretical discussions on exfoliation kinetics are introduced, aimed at gaining an understanding of the exfoliation process. Applications based on the liquid-phase exfoliated graphene are also briefly presented.