Raman Fingerprints of Graphene Produced by Anodic Electrochemical Exfoliation

TL;DR

This study systematically analyzes the Raman spectrum of electrochemically exfoliated graphene, revealing how experimental conditions influence defect formation and providing guidance for using Raman spectroscopy as a metrology tool.

Contribution

It offers the first comprehensive Raman spectral analysis of electrochemically exfoliated graphene under various conditions, clarifying defect and thickness information.

Findings

Raman spectra do not indicate thickness due to defects.

Defect levels depend on electrolyte, temperature, and processing.

Short trans-polyacetylene chains can form under certain conditions.

Abstract

Electrochemical exfoliation is one of the most promising methods for scalable production of graphene. However, limited understanding of its Raman spectrum as well as lack of measurement standards for graphene strongly limit its industrial applications. In this work we show a systematic study of the Raman spectrum of electrochemically exfoliated graphene, produced using different electrolytes and different types of solvents in varying amounts. We demonstrate that no information on the thickness can be extracted from the shape of the 2D peak as this type of graphene is defective. Furthermore, the number of defects and the uniformity of the samples strongly depend on the experimental conditions, including post-processing. Under specific conditions, formation of short conductive trans-polyacetylene chains has been observed. Our Raman analysis provides guidance for the community on how to get information on defects coming from electrolyte, temperature and other experimental conditions, by making Raman spectroscopy a powerful metrology tool.