• 文献标题:   Factors Affecting the Exfoliation of Graphite Intercalation Compounds for Graphene Synthesis
  • 文献类型:   Article
  • 作  者:   YOON G, SEO DH, KU K, KIM J, JEON S, KANG K
  • 作者关键词:  
  • 出版物名称:   CHEMISTRY OF MATERIALS
  • ISSN:   0897-4756 EI 1520-5002
  • 通讯作者地址:   Seoul Natl Univ
  • 被引频次:   35
  • DOI:   10.1021/cm504511b
  • 出版年:   2015

▎ 摘  要

We investigate the mechanism of the intercalation-aided exfoliation of graphite using van der Waals force-corrected density functional theory (DFT) calculations. From a comparative study on various intercalation systems, we find that, depending on the intercalant species, the exfoliation energies vary significantly, not only due to the size of intercalants but also due to interactions with the host graphite. While it is generally perceived that an expanded interlayer distance with intercalants weakens the binding between graphene layers, as the van der Waals forces decrease, the calculations reveal that the intercalation of electronegative or electropositive intercalants (e.g., Li, K, F, Cl, and Br) result in a 1.5-5-fold higher exfoliation energy than pristine graphite due to additional binding forces from charge transfer between intercalants and graphene layers. Furthermore, we demonstrate that this additional binding force could be manipulated with cointercalation or neutral intercalants, which hints at effective exfoliation strategies with graphite intercalation compounds. This theoretical study broadens our understanding of the mechanism underlying graphite exfoliation and will facilitate development of more effective exfoliation strategies for other related layered materials.