The Effect of Liquid Media on the Efficiency of Graphene Production by Liquid-Phase Exfoliation from Micromechanically Pre-exfoliated Graphite

Abstract

Graphene can be produced using several methods. One of the most successful production methods in terms of scale-up is liquid-phase exfoliation (LPE). With this method, the solvent employed during exfoliation is a critical parameter. In the present study, hexagonal graphite powders were micromechanically exfoliated using a low-energy ball mill, and the expanded graphite was then obtained from the micromechanically exfoliated graphite. Finally, the graphenes were synthesized using LPE. N-Methyl-2-pyrrolidone (NMP) and N,N-dimethylformamide (DMF) were the most successful solvents used for producing graphene by the LPE method. Naphthalene and sodium dodecyl sulfate (SDS) were added to these solvents to improve production efficiency. The chemicals yielding the best results were determined by analyzing the graphenes. While 3–5-layer graphenes were produced in all liquid media, the amount of high-quality graphenes differed among samples. The most efficient graphene was obtained in the samples produced using NMP + SDS liquid media. The production efficiency obtained in these samples as a result of the exfoliation process was 25%. The samples produced with NMP were more successful than those produced with DMF.