Temperature and pressure dependent Raman spectroscopy of plasma treated multilayer graphene nanosheets

Pawbake, Amit; Mishra, K. K.; Machuno, Luís Gustavo Baptista; Gelamo, Rogério Valentim; Ravindran, T. R.; Rout, Chandra Sekhar; Late, Dattatray J.

doi:10.1016/j.diamond.2018.03.021

Cited by 22 publications

(11 citation statements)

References 51 publications

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“…The D peak was found here to be narrow and considerably less intense than the G peak. The structure of the D peak is similar to what is usually found for graphene nanosheets [33]. However, the low-intensity ratios, i.e., I D /I G = 0.08 and I D /I G = 0.10, are related to the nanosheet edges rather than basal in-plane defects [32,34].…”

Section: Resultssupporting

confidence: 79%

Zeolite-Assisted Shear Exfoliation of Graphite into Few-Layer Graphene

et al. 2019

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A novel method is presented to prepare few-layer graphene (FLG) in N-methyl-2-pyrrolidinone (NMP) by using a simple, low-cost and energy-effective shear exfoliation assisted by zeolite and using a cappuccino mixer to produce shear. We propose that the exfoliation of natural graphite flakes can be achieved using inelastic collisions between graphite flakes and zeolite particles in a dynamic colloidal fluid. To confirm the exfoliation of FLG, spectroscopy and morphological studies are carried out using Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Additionally, the obtained graphene shows a linear flow of current and low resistance. The proposed method shows great promise for the industrial-scale synthesis of high-quality graphene with potential applications in future graphene-based devices, and furthermore, this method can be extended to exfoliate inorganic layered materials such as BN and MoS 2 .

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Section: Resultssupporting

confidence: 79%

Zeolite-Assisted Shear Exfoliation of Graphite into Few-Layer Graphene

et al. 2019

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“…Plasma treatment is one of the most effective methods for surface modication of semiconductor materials in both types of thin lms and nanowires. [11][12][13][14][15][16]40 In this study, oxygen plasma was employed to modify the surface of the ZnO NW-based IDA-PDs. By comparison, the performance of the IDA-PDs treated by oxygen plasma for 10 minutes showed great improvement.…”

Section: Introductionmentioning

confidence: 99%

Oxygen plasma assisted enhanced photoresponse of ZnO nanowires fabricated by catalyst-free chemical vapor deposition

et al. 2018

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In this paper, in order to enhance the performance of fabricated ZnO nanowires (NWs) by chemical vapor deposition (CVD) without catalysts, oxygen plasma was used to modify the ZnO nanowire-based interdigital microelectrode array photodetectors (IDA-PDs) at different times. The surface states of ZnO NWs with O 2 plasma treatment were characterized via X-ray photoelectron spectroscopy (XPS). Results showed that the photocurrent of the IDA-PDs continuously increased from 4 to 28 mA as the plasma-treatment time increased from 0 to 10 minutes. The response mechanism of O 2 plasma treated ZnO NWs was investigated by illustrating the intensity of the surface oxygen atoms of ZnO NWs.This sample handling method can be beneficial in improving the performance of semiconductor photodetectors.

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“…The Raman spectra of graphene have several characteristic bands, which are usually denoted as D, G, Dʹ and 2D bands [1][2][3][4]. The presence of the D band indicates certain defects that can be caused by both imperfection of the crystal lattice and the presence of impurities [5]. Usually the ratio of the intensities of G and D bands is determined for quality control [2].…”

Section: Introductionmentioning

confidence: 99%

“…It has been found that the D and Dʹ peaks intensity coefficient is maximum (~13) for sp 3 -defects, decreases for vacancy defects (~7), and reaches a minimum for defects at the graphite boundary (~3.5). Raman spectroscopy is one of the most sensitive methods for determining disorder in sp 2 carbon materials, since the presence of disorder in sp 2 hybridized carbon systems leads to resonance in Raman spectra [5].…”

Section: Introductionmentioning

confidence: 99%

Influence of edge defects on Raman spectra of graphene

et al. 2020

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The effect of the vacancy edge defect (bonds breaking between carbon atoms) of a graphene sheet on the Raman spectrum was studied. The spectra were calculated using the density functional theory (DFT) using the Gaussian-09 program. Modeling of a graphene sheet fragment with a break of one bond between carbon atoms at the edge showed that changes in the Raman spectrum were common for the presence of nitrogen and oxygen atoms. In this case, the strongest D lines appear in functionalized graphene with oxygen atoms, and the Dʹ lines-in nitrogen-doped graphene. This is confirmed by the experimental Raman spectra as well as calculated ones. The strongest 2D line is characteristic of the graphene model without impurities; the presence of other oxygen or nitrogen atoms leads to a decrease in its intensity. Modeling of a graphene sheet fragment with a break of one bond between carbon atoms at the edge showed that changes in the spectrum are common for both cases of graphene nitrogen-doping and functionalization with oxygen atoms. A comparison of the experimental data with the simulation results showed good agreement between the data. Moreover, the vibrations of hydrogen atoms linked by covalent bonds with neighboring carbon atoms moved towards each other in disturbed hexagonal structures located on the edge of the graphene sheet. Such a steric effect led to a decrease in the frequency of the stretching vibration q(CH), which appeared in the region of ~2700 cm −1 and corresponded to the 2D vibration. The results of the vacancy edge defect modeling for the graphene sheet fragment being nitrogen-doped and functionalized by oxygen atoms were compared with experimental data.

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Temperature and pressure dependent Raman spectroscopy of plasma treated multilayer graphene nanosheets

Cited by 22 publications

References 51 publications

Zeolite-Assisted Shear Exfoliation of Graphite into Few-Layer Graphene

Zeolite-Assisted Shear Exfoliation of Graphite into Few-Layer Graphene

Oxygen plasma assisted enhanced photoresponse of ZnO nanowires fabricated by catalyst-free chemical vapor deposition

Influence of edge defects on Raman spectra of graphene

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