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 language | English |
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Pages (from-to) | 3552-3559 |
Number of pages | 8 |
Journal | Langmuir |
Volume | 32 |
Issue number | 14 |
DOIs | |
Publication status | Published - 26 Apr 2016 |