title: Shear Assisted Electrochemical Exfoliation of Graphite to Graphene.
abstract: The exfoliation characteristics of graphite as a function of applied anodic potential (1-10 V) in combination with shear field (400-74 400 s(-1)) have been studied in a custom-designed microfluidic reactor. Systematic investigation by atomic force microscopy (AFM) indicates that at higher potentials thicker and more fragmented graphene sheets are obtained, while at potentials as low as 1 V, pronounced exfoliation is triggered by the influence of shear. The shear-assisted electrochemical exfoliation process yields large (∼10 μm) graphene flakes with a high proportion of single, bilayer, and trilayer graphene and small ID/IG ratio (0.21-0.32) with only a small contribution from carbon-oxygen species as demonstrated by X-ray photoelectron spectroscopy measurements. This method comprises intercalation of sulfate ions followed by exfoliation using shear induced by a flowing electrolyte. Our findings on the crucial role of hydrodynamics in accentuating the exfoliation efficiency suggest a safer, greener, and more automated method for production of high quality graphene from graphite.
authors.forename: Dhanraj B
authors.initials: DB
authors.lastname: Shinde
authors.forename: Jason
authors.initials: J
authors.lastname: Brenker
authors.affiliation: CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, VIC Australia.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Easton
authors.forename: Rico F
authors.initials: RF
authors.lastname: Tabor
authors.forename: Adrian
authors.initials: A
authors.lastname: Neild
authors.forename: Mainak
authors.initials: M
authors.lastname: Majumder