Scalable production of electrochemically exfoliated graphene by an extensible electrochemical reactor with encapsulated anode and dual cathodes

Abstract

Graphene is a carbon material with excellent physical and chemical properties, and the wide-range applications of graphene rely on the realization of its large-scale production. Electrochemical exfoliation is a green and low-cost technology ideal for large-scale graphene production. However, the falling of large particles and disconnection of large chunks of the substrate ascribing to the uncontrolled and uneven exfoliation of graphite during the process leads to low yield. Here, an efficient encapsulate electrode for the electrochemical exfoliation approach is developed, in which graphite particles can be accessed to potential connect during the overall exfoliation. Using flexible encapsulated graphite with filter cloth as both anode and cathode for the electrolyzer can approach deep exfoliation and achieve a high yield of graphene. With this new design, the yield of graphene is increased from 31 % to 57 %, while the graphene’s oxygen content (O% ∼20 %) has no distinct increase compared to the bare one (O% ∼17 %). Moreover, the exfoliation rate of the larger extensible electrochemical reactor can approach 70 g h-1, and the graphene sheets are 3 ∼ 6 layers. This simple and practical electrode with efficient exfoliation will boost the development of large-scale production of graphene and access to its application.