Journal article

Authors list: Schuepfer, DB; Badaczewski, F; Guerra-Castro, JM; Hofmann, DM; Heiliger, C; Smarsly, B; Klar, PJ

Publication year: 2020

Pages: 359-372

Journal: Carbon

Volume number: 161

ISSN: 0008-6223

eISSN: 1873-3891

Open access status: Hybrid

DOI Link: https://doi.org/10.1016/j.carbon.2019.12.094

Publisher: Elsevier

Abstract: 
We study the transformation from molecular to crystalline of (non-)graphitic carbons synthesized from organic precursors by heat-treatment. Easy assessment of structural properties resulting from heat-treatment protocols is mandatory for industrial process monitoring. We demonstrate that Raman spectroscopy, in particular, the Raman lineshape analysis of G and D mode, offers quick assessment of the average sheet size of such carbons. We validate this method by performing Raman, WAXS and EPR measurements of series of resin and pitch-based carbons synthesized. The crystallite sizes of the WAXS analysis for the individual samples are related to corresponding positions and linewidths of G and D Raman modes and show excellent agreement between experiment and modelling from large sizes down to 4 nm. The theoretical master curves are independent of the precursor used in the synthesis, in contrast to models for the intensity ratio of D and G band versus size. We show that the latter are not universally valid and differ for each class of precursors. For sizes below 4 nm, our lineshape model fails as it is based on the bandstructure and phonon dispersions of ideal graphene. Thus, 4 nm corresponds to the fundamental transition from molecular to crystalline character for non-graphitic carbons. (C) 2020 The Authors. Published by Elsevier Ltd.

Harvard Citation style: Schuepfer, D., Badaczewski, F., Guerra-Castro, J., Hofmann, D., Heiliger, C., Smarsly, B., et al. (2020) Assessing the structural properties of graphitic and non-graphitic carbons by Raman spectroscopy, Carbon, 161, pp. 359-372. https://doi.org/10.1016/j.carbon.2019.12.094

APA Citation style: Schuepfer, D., Badaczewski, F., Guerra-Castro, J., Hofmann, D., Heiliger, C., Smarsly, B., & Klar, P. (2020). Assessing the structural properties of graphitic and non-graphitic carbons by Raman spectroscopy. Carbon. 161, 359-372. https://doi.org/10.1016/j.carbon.2019.12.094