Graphite and multi-layer graphene from a low molecular weight carbon source

Abstract

While carbonaceous structures formed by pyrolysis of macromolecular carbon sources with silicates are well described in the literature, information on the structure of carbons obtained in the similar way from low molecular weight (LMW) carbon sources is not sufficient. This study is therefore aimed at characterizing the material obtained by pyrolyzing (1300 °C; Ar atmosphere) montmorillonite containing ∼25–50 wt% LMW cations as a carbon source. Pyrolyzed samples contained ∼5–20 wt% carbon, and thermogravimetric and elemental analysis showed a higher yield for a higher original amount of the LMW carbon source. In addition to amorphous carbon, graphite was formed during pyrolysis, as confirmed by X-ray diffraction analysis, Raman spectroscopy, and X-ray photoelectron spectroscopy. The presence of graphene-based nanomaterial, specifically multi-layer graphene, was revealed by transmission electron microscopy (TEM). Electrical conductivity of the silicate/carbon material reached ∼35 S m⁻¹. Raman spectra and TEM images are similar to those from studies describing the use of macromolecular carbon sources. LMW compounds are a sufficient source of carbon for the preparation of electrically conductive materials containing graphite and multi-layer graphene.