Shear assisted electrochemical exfoliation of graphite to graphene

Dhanraj B. Shinde, Jason Brenker, Christopher D. Easton, Rico F. Tabor, Adrian Neild, Mainak Majumder

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32 Citations (Scopus)

Abstract

The exfoliation characteristics of graphite as a function of applied anodic potential (1-­10V) 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 carbon­oxygen species as demonstrated by X­ray 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.
Original languageEnglish
Pages (from-to)3552-3559
Number of pages8
JournalLangmuir
Volume32
Issue number14
DOIs
Publication statusPublished - 26 Apr 2016

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