Fabrication of binderless electrodes via non-destructive electrochemical oxidation/reduction of graphite sheets using BF4 salts

•Graphite sheet was electrochemically oxidized uniformly using BF4 salt electrolyte.•The oxidized graphite sheet was electrochemically reduced directly.•Electrochemical oxidation and reduction provides high quality graphene oxide and reduced graphene oxide.•A laminated capacitor was assembled by electrochemically oxidized and reduced graphite sheet without binder and current collector. We report the electrochemical oxidation of graphite sheets using BF4 salts, and direct electrochemical reduction of its product to prepare two-dimensional carbon materials efficiently. Electrochemical oxidation enables the synthesis of graphene oxide (GO) under milder conditions than those required for chemical oxidation, e.g., a strong oxidant in concentrated acid. In this work, graphite sheet was electrochemically oxidized with BF4 salt electrolyte solution, and its product was electrochemically reduced in PBS. In the present method, the use of BF4 salt allows the successful electrochemical synthesis of high-quality, uniform GO without the use of an acid. Furthermore, the non-destructive nature of the method provides a GO product that can be subjected to electrochemical reduction to form reduced GO. Thus, the method provides facile access to high-quality two-dimensional carbon materials in a manner that has the potential for mass production.