Raman spectroscopic studies on well-defined carbonaceous materials of strong two-dimensional character

Abstract

Using 514 nm radiation and a careful experimental protocol allowing us to make quantitative intensity analyses, we have examined the first- and second-order Raman spectra of five varieties of graphite. These include single-crystal graphite and highly oriented pyrolytic graphite as references, then two with a significant content of c-axis translation faults introduced through grinding and exfoliation, and a last sample which is purely turbostratic. We show that full c-axis stacking disorder results in a strong increase of the scattered E2g-mode intensity. We have further shown that even in those strongly disordered stacking sequences, but in which the AB sequence persists over only a few layers, the doublet around 2700 cm−1 is resolved. We argue against assigning the peak around 1355 cm−1 to “disorder,” as is so often done, but to the finite in-plane domain size as proposed a number of years ago; moreover, we suggest that this peak is a more sensitive probe of such small domains than is x-ray diffraction.

Chemical Mapping and Electrochemical Performance of Manganese Dioxide/Activated Carbon Based Composite Electrode for Asymmetric Electrochemical Capacitor

“…[48][49][50] Fig . 5a shows the Raman spectra of pristine BP, which is characterized by the typical D (1334 cm −1 ) and G (1598 cm −1 ) bands.…”

“…46,47 At the same time, Raman spectroscopy has been proved to be a useful tool to study the vibrational properties and electronic structures of carbon materials. [48][49][50] Interestingly, information about the distribution or the physical properties such as conductivity of an electrode material could be obtained using Raman mapping technique. 46,47,[51][52][53] In this paper, two different types of composite electrodes were prepared.…”

“…46,47 At the same time, Raman spectroscopy has been proved to be a useful tool to study the vibrational properties and electronic structures of carbon materials. [48][49][50] Interestingly, information about the distribution or the physical properties * Electrochemical Society Student Member.…”

In situ formation of onion-like carbon from the evaporation of ultra-dispersed nanodiamonds

“…The ratio of the intensities of these two bands is often used as a measure of disorder in graphitic materials [23]. The evaporated OLC displays a ratio of D band to G band intensity (I D /I G ) of 0.95, the relative strength of the D band implies that the OLC particles are highly defective in accord with the HRTEM and XPS data, although the nature of the defects associated with the graphite D band is a matter of debate [24,25]. Similarly, the full width at half maximum (FWHM) of the D band of 77 cm -1 is rather large, providing further evidence of the defective nature of the evaporated OLC particles.…”

Role of nanocrystalline domain size on the electrochemical double-layer capacitance of high edge density carbon nanostructures

“…[35] Comparing this Raman expression with crystallite size estimates by x-ray Research Letter diffraction, the larger crystallites are given less weight in this case and the above expression underestimates L a due to the dominant effect of small crystallites. [36][37][38] Bearing in mind the limitations of the above formulation of crystalline domain size, the trends detailed in this letter are nevertheless tooted in the existence and spatial frequency of defects in the materials. Thus, L a can be equally referred to as the mean spacing between defects, including the edge defects that are prominent in the materials of the current study.…”