• 文献标题:   Preparation of high-quality graphene with a large-size by sonication-free liquid-phase exfoliation of graphite with a new mechanism
  • 文献类型:   Article
  • 作  者:   ZHANG R, ZHANG BC, SUN SQ
  • 作者关键词:  
  • 出版物名称:   RSC ADVANCES
  • ISSN:  
  • 通讯作者地址:   Tianjin Univ
  • 被引频次:   15
  • DOI:   10.1039/c5ra04480d
  • 出版年:   2015

▎ 摘  要

In this paper, we report on the successful preparation of high-quality graphene sheets with a large-size in N, N-dimethylformamide (DMF) solvent by sonication-free liquid-phase exfoliation (LPE) of graphite assisted with urea as the precursor of the intercalating agent melamine. Through the characterizations of the graphene sheets obtained with transmission electron microscopy (TEM), atomic force microscopy (AFM), Raman spectroscopy and XPS, these graphene sheets were found to be high-quality, defect-free, single or-few-layer with areas in the range of 100-1000 mu m(2). The influences of reflux time and the mass ratio of urea to graphite on the graphene concentration (CG) in the resulting dispersions were investigated. The graphene dispersions were fabricated into flexible films that show comparable conductivity. The exfoliation mechanism of graphite in our new sonication-free LPE method is also discussed.