Bulk Production of Any Ratio 12C: 13C Turbostratic Flash Graphene and Its Unusual Spectroscopic Characteristics

As graphene enjoys worldwide research and deployment, the biological impact, geologic degradation, environmental retention, and even some physical phenomena remain less well studied. Bulk production of C-13-graphene yields a powerful route to study all of these questions. Gram-scale synthesis of high-quality and high-purity turbostratic flash graphene with varying amounts of C-13-enrichment, from 5% to 99%, is reported here. The material is characterized by solid state NMR spectroscopy, Raman spectroscopy, IR spectroscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma mass spectrometry. Notably, an unusual enhancement in the Raman spectroscopic D' peak is observed, resulting from the modification in vibrational frequency through isotopic enrichment favoring intravalley phonon scattering modes. While the IR absorbance spectrum of graphene is for the most part silent, we prepare here C-13-enhanced graphene samples that show a large aromatic C-12=C-13 stretch that reveals this IR-active mode.

Automated summary

This study reported a method for large-scale synthesis and characterization of C-13 graphene, analyzing samples with different enrichment levels and detecting unusual phenomena in solid-state NMR and Raman spectroscopy.