• 文献标题:   Scanning-Raman-Microscopy for the Statistical Analysis of Covalently Functionalized Graphene
  • 文献类型:   Article
  • 作  者:   ENGIERT JM, VECERA P, KNIRSCH KC, SCHAFER RA, HAUKE F, HIRSCH A
  • 作者关键词:   graphene, raman, covalent functionalization, intercalation compound, raman statistic
  • 出版物名称:   ACS NANO
  • ISSN:   1936-0851 EI 1936-086X
  • 通讯作者地址:   Univ Erlangen Nurnberg
  • 被引频次:   77
  • DOI:   10.1021/nn401481h
  • 出版年:   2013

▎ 摘  要

We report on the introduction of a systematic method for the quantitative and reliable characterization of covalently functionalized graphene based on Scanning-Raman-Microscopy (SRM). This allows for recording and analyzing several thousands of Raman spectra per sample and straightforward display of various Raman properties and their correlations with each other in histograms or coded 2D-plots. In this way, information about the functionalization efficiency of a given reaction, the reproducibility of the statistical analysis, and the sample homogeneity can be easily deduced. Based on geometric considerations, we were also able to provide, for the first time, a correlation between the mean defect distance of densely packed point defects and the Raman I-D/I-G ratio directly obtained from the statistical analysis. This proved to be the prerequisite for determining the degree of functionalization, termed theta. As model compounds, we have studied a series of arylated graphenes (GPh) for which we have developed new synthetic procedures. Both graphite and graphene grown by chemical vapor deposition (CVD) were used as starting materials. The best route toward GPh consisted of the initial reduction of graphite with a Na/K alloy in 1,2-dimethoxyethane (DME) as it yields the highest overall homogeneity of products reflected in the widths of the Raman I-D/I-G histograms. The Raman results correlate nicely with parallel thermogravimetric analysis (TGA) coupled with mass spectrometry (MS) studies.