The Exfoliation of Graphene in Liquids by Electrochemical, Chemical, and Sonication-Assisted Techniques: A Nanoscale Study

• Published in: Advanced functional materials Vol. 23; no. 37; pp. 4684 - 4693
• Main Authors: Xia, Zhen Yuan, Pezzini, Sergio, Treossi, Emanuele, Giambastiani, Giuliano, Corticelli, Franco, Morandi, Vittorio, Zanelli, Alberto, Bellani, Vittorio, Palermo, Vincenzo
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 04.10.2013; WILEY‐VCH Verlag
• Subjects: electrochemistry; Exfoliation; Graphene; graphene oxide; Graphite; Nanomaterials; Nanostructure; Preservation; Scanning electron microscopy; scanning probe microscopy; Solvents; surface science
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201203686

The different exfoliation routes of graphite to produce graphene by sonication in solvent, chemical oxidation and electrochemical oxidation are compared. The exfoliation process and roughening of a flat graphite substrate is directly visualized at the nanoscale by scanning probe and electron microscopy. The etching damage in graphite and the properties of the exfoliated sheets are compared by Raman spectroscopy and X‐ray diffraction analysis. The results show the trade‐off between exfoliation speed and preservation of graphene quality. A key step to achieve efficient exfoliation is to couple gas production and mechanical exfoliation on a macroscale with non‐covalent exfoliation and preservation of graphene properties on a molecular scale. The different exfoliation routes of graphite to produce graphene by sonication in solvent, chemical oxidation, and electrochemical oxidation are compared. The results obtained show the trade‐off between exfoliation speed and preservation of graphene quality. A key step to achieve efficient exfoliation is to couple gas production and mechanical exfoliation on a macroscale with non‐covalent exfoliation and preservation of graphene properties on a molecular scale.