▎ 摘　　要

A Li+-OH exfoliation system was designed to prepare graphene in water without surfactants or sonication. Due to the positive charge transferred from intercalating Li+ ions to adjacent C atoms, OH could add on the graphene sheets and further promote their affinity to water, resulting in efficient exfoliation of graphene in water. The as-prepared graphene concentration was up to 0.09 mg.mL (1), and sheet sizes range from 1 to 2 mu m. Detailed characterizations revealed the formation of high-quality and few-layer graphene sheets and confirmed the addition of hydroxyl groups on graphene sheets during exfoliation. This strategy has potential in scalable production of graphene in aqueous phase. (C) 2018 Elsevier B.V. All rights reserved.