Study of potassium intercalated graphite by Raman spectroscopy

Abstract

In this paper, a study of a graphite intercalation compound by potassium was carried out using Raman spectroscopy. The purpose of the study was to determine the intercalation stage and study the influence of intercalated atoms on the vibrational properties of highly oriented pyrolytic graphite lattice. The intercalation of highly oriented pyrolytic graphite by potassium was performed using a two-zone method. Raman spectra were obtained for both pure and intercalated highly oriented pyrolytic graphite. The experiments carried out to identify the synthesized structures showed the formation of sixth stage graphite intercalation compound. Knowledge of the stage of the intercalated graphite compounds is important for its use as a superconducting material, as well as in supercapacitors. In addition, the intercalation stage is a key factor in obtaining graphene by chemical exfoliation of graphite intercalation compound, since the number of graphene layers will directly depend on the intercalation stage. In the obtained Raman spectra, the effect of G-peak splitting is observed, indicating a change in the vibrational properties of the graphite lattice during its intercalation due to the charge transfer from the intercalate to the carbon layers. The value of the transferred charge is determined using first-principles calculations.