High-rate production of few-layer graphene by high-power probe sonication

Graphene can be obtained via sonication-assisted liquid-phase exfoliation, but the production rate of few-layer graphene (FLG) is still low. A high-power probe sonicator was used in this study to improve the production rate of FLG, and its performance was optimized by controlling processing parameters such as the initial graphite concentration, surfactant concentration and liquid volume. By optimizing processing parameters, production rate of FLG dispersions in N-methyl-2-pyrrolidone (NMP) were greater than 1 g/h, which is the best value achieved in the sonication-assisted exfoliation process. In the case of liquid exfoliation in water/surfactant solution, production rate of FLG was achieved approximately 0.28 g/h. Our work here demonstrates that graphene concentration in a probe-sonication process does not depend on the shape of vessel, and it is predictable by power law models. (C) 2015 Elsevier Ltd. All rights reserved.