Abstract 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 μm. 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.

中文翻译：

---

无表面活性剂和无超声处理的石墨烯水分散体剥离方法

摘要 Li+-OH- 剥离系统旨在在没有表面活性剂或超声处理的情况下在水中制备石墨烯。由于正电荷从嵌入的 Li+ 离子转移到相邻的 C 原子，OH− 可以添加到石墨烯片上并进一步促进它们对水的亲和力，从而导致石墨烯在水中的有效剥离。所制备的石墨烯浓度高达 0.09 mg·mL-1，薄片尺寸范围为 1 至 2 μm。详细的表征揭示了高质量和少层石墨烯片的形成，并证实了在剥离过程中在石墨烯片上添加了羟基。该策略在水相石墨烯的规模化生产方面具有潜力。