Related Experiment Video
Updated: Oct 29, 2025
08:57
Scalable Syntheses of Graphene Oxide and Reduced Graphene Oxide using Cascade Design Oxidation and Highly Basic Reduction Reactions
Published on: July 3, 2025
1.1K
Multistep Fractionation of Coal and Application for Graphene Synthesis
Kaustubh Rane1, Jeramie J Adams2, James M Thode3
1Department of Petroleum Engineering, University of Wyoming, 1000 E. University Avenue, Laramie, Wyoming 82071, United States.
ACS Omega
|July 8, 2021
Summary
This study developed a coal fractionation method to produce high-quality graphene precursors. The resulting aromatic fractions yielded defect-free graphene on nickel but amorphous carbon on copper, highlighting substrate influence.
Area of Science:
- Materials Science
- Nanotechnology
- Chemical Engineering
Background:
- Coal is a potential precursor for graphene synthesis via chemical vapor deposition (CVD).
- Coal's inherent heteroatoms and aliphatic chains introduce defects, hindering pristine graphene formation.
- A refined precursor is needed to overcome these limitations for high-quality graphene.
Purpose of the Study:
- To develop a multistep fractionation scheme for coal to isolate ideal aromatic graphene precursors.
- To characterize these fractions and evaluate their performance in graphene synthesis via CVD.
Main Methods:
- A multistep fractionation process including direct coal liquefaction, Soxhlet extraction (heptane, toluene), and preparative liquid chromatography (heptol).
- Characterization of fractions using proton nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), elemental analysis, and automated SAR-AD separations.
- Graphene synthesis by CVD on nickel and copper substrates, followed by Raman spectroscopy and transmission electron microscopy (TEM) analysis.
Main Results:
- Two aromatic fractions, one with and one without heteroatoms, were successfully isolated.
- Defect-free, multilayered graphene (approx. 11 layers) was synthesized on nickel from both fractions.
- Amorphous carbon formed on copper due to hydrogen solubility, with heteroatoms promoting agglomeration.
Conclusions:
- The substrate significantly influences graphene quality: nickel promotes defect-free graphene, while copper favors amorphous carbon.
- Precursor quality is critical for graphene formation on copper, with heteroatom-free fractions yielding larger domains.
- This fractionation method effectively produces tailored coal-derived precursors for controlled graphene synthesis.
