Study of Anodic Electrochemical Exfoliation of Graphite Under Acidic Electrolyte for Scalable Production of Graphene

Abstract

Graphene has attracted many attentions due to its exceptional mechanical, thermal, electrical, and chemical properties. There has been active research for scalable production of high-quality graphene from graphite. Anodic electrochemical exfoliation of graphite is one of the promising methods for fast and simple production of graphene at low cost with moderate quality. Sulfate containing electrolytes are known for highest exfoliation efficiency among anions, however mechanistic details of exfoliation process remain poorly understood. Here, the role of sulfate anion during the exfoliation process is studied by comparing with other anions under acid conditions. We reveal that water molecules are the main source of gaseous species that exfoliates graphite via mass spectroscopy. The formation and binding energy of anions between graphene layers are also calculated by DFT computations. The fundamental understanding of the exfoliation mechanism of graphite can be applicable to the electrochemical production of other 2D materials.