Shear Assisted Electrochemical Exfoliation of Graphite to Graphene
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- 作者：Dhanraj B. Shinde ; Jason Brenker ; Christopher D. Easton ; Rico F. Tabor ; Adrian Neild ; Mainak Majumder
- 刊名：Langmuir
- 出版年：2016
- 出版时间：April 12, 2016
- 年：2016
- 卷：32
- 期：14
- 页码：3552-3559
- 全文大小：422K
- 年卷期：0
- ISSN：1520-5827
文摘
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.