Role of Peroxide Ions in Formation of Graphene Nanosheets by Electrochemical Exfoliation of Graphite

This study demonstrates a facile, mild and environmentally-friendly sustainable (soft processing) approach for the efficient electrochemical exfoliation of graphite using a sodium hydroxide/hydrogen peroxide/water (NaOH/H(2)O(2)/H(2)O) system that can produce high-quality, anodic few-layer graphene nanosheets in 95% yield at ambient reaction conditions. The control experiment conducted using NaOH/H(2)O revealed the crucial role of H(2)O(2) in the exfoliation of graphite. A possible exfoliation mechanism is proposed. The reaction of H(2)O(2) with hydroxyl ions (HO(−)) leads to the formation of highly nucleophilic peroxide ions (O(2)(2−)), which play a crucial role in the exfoliation of graphite via electrochemical-potential-assisted intercalation and strong expansion of graphite sheets.