Raman

Applied Surface Science 536 (2021) 147990
Contents lists available at ScienceDirect
Applied Surface Science
journal homepage: www.elsevier.com/locate/apsusc
Raman study of D* band in graphene oxide and its correlation with
reduction
T
A Young Leea,b, Kihyuk Yanga, Nguyen Duc Anha, Chulho Parka, Seung Mi Leec, Tae Geol Leeb, ,
⁎
Mun Seok Jeonga,
⁎
a
Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
Nanosafety Team, Safety Measurement Institute, Korea Research Institute of Standards and Science, Daejeon 34113, Republic of Korea
c
Surface Analysis Team, Interdisciplinary Materials Measurement Institute, Korea Research Institute of Standards and Science, Daejeon 34113, Republic of Korea
b
ARTICLE INFO
ABSTRACT
Keywords:
Raman spectroscopy
Reduced graphene oxide
Thermal reduction
Density functional perturbation theory
Reduced graphene oxide (rGO) is a graphene-like material that exhibits high productivity for a wide range of
industrial applications. To promote the application of rGO, it is important to not only produce high-quality rGO
but also precisely evaluate the output. The intensity ratio of the D to G band in the Raman scattering is commonly used to assess the defect density of the carbon materials; however, this ratio is limited to evaluate the
reduction degree of rGO because of the ambiguity arising from the superposition of the bands. In this study, we
investigate the relationship between the intensity ratio of D* to G band and the reduction of graphene oxide (GO)
to evaluate the degree of reduction of rGO. The spectral analysis of GO and rGO, along with systematic research
of the thermally reduced GO synthesized via thermal treatment (100–900 °C) revealed a strong linkage between
the D*/G intensity ratio and the C/O atomic ratio. The atomic vibrational relationships were elucidated by the
assignment of the D* band, based on the density functional perturbation theory calculations. These findings
explain the atomic vibrational properties of rGO and provide an indicator of the quality of rGO to optimize its
performance for applications.
1. Introduction
Graphene is a two-dimensional plane sheet of sp2-hybridized carbon
atoms that are arranged in a honeycomb lattice structure. Since the
development of defect-free monolayer graphene using mechanical exfoliation in 2004 [1], graphene has been widely utilized in diverse
fields such as supercapacitor electrodes [2], conductive agents [3],
active electrode materials for lithium-ion batteries [4], and biosensors
[5,6], owing to its strong merits of a large specific surface area, excellent electrical properties, high chemical stability, extreme sensitivity, and high mechanical properties [7–9]. High-quality graphene is
prepared via bottom-up techniques such as chemical vapor deposition
[10], and epitaxial growth on silicon carbide [11]. However, the
commercialization of these methods is economically unviable because
of their limited scalability and the need for high temperature and vacuum conditions. For the industrial mass production of graphene, reduced graphene oxide (rGO), a graphene-like sheet, was developed by
reducing the oxygen-containing functional groups of graphene oxide
(GO) [12,13].
Raman spectroscopy has been widely employed to characterize the
⁎
molecular structures of carbon products, because of the resonantly
enhanced Raman scattering of carbon materials; thus, graphene shows
well-defined vibration bands [14]. In addition, Raman spectral analysis
allows the assessment of the disorder and defects in carbon materials
through the measurement of the intensity ratio of the D band to G band
(I(D)/I(G) ratio) [15]. Nevertheless, in the case of GO and rGO, it is
necessary to reconsider whether the I(D)/I(G) ratio provides accurate
information, considering the ambiguity of the vibration information
due to the superposition of the bands [16]. In addition, the intensity
ratio falls unexpectedly in the high-defect density regimes since a large
number of amorphous carbons attenuate all the Raman modes [17]. To
find alternatives to the I(D)/I(G) ratio, researchers have investigated
other Raman bands through the deconvolution of the Raman spectra of
GO and rGO. The spectral parameters have been investigated and correlated with the structural properties, which revealed their relationship
with the oxygen content, crystallinity, and degree of disorders of rGO.
The positions of the D'' and D* peaks obtained after deconvolution,
which was performed using a combination of five functions, show good
correlations with the oxygen content and can thus be used to estimate
the degree of reduction [18]. Raman metrics with D' and G bands were
Corresponding authors.
E-mail addresses: [email protected] (T.G. Lee), [email protected] (M.S. Jeong).
https://doi.org/10.1016/j.apsusc.2020.147990
Received 4 July 2020; Received in revised form 22 September 2020; Accepted 24 September 2020
Available online 28 September 2020
0169-4332/ © 2020 Elsevier B.V. All rights reserved.
Applied Surface Science 536 (2021) 147990
A.Y. Lee, et al.
Fig. 1. SEM images of (a) GO and (b) rGO. (c) Photograph of GO and rGO dispersions in water. (d) UV–Vis absorption spectra of GO and rGO. Fitted Raman spectra of
(e) GO and (f) rGO, respectively.
developed to investigate the degree of reduction. The difference in the
positions of the inferred D mode and the apparent G mode is associated
with GO reduction [16]. Furthermore, the second-order Raman bands
show a direct correlation with the electrical resistance of laser-reduced
GO [19]. However, these relations are only partially described due to a
lack of understanding of the origins of the peaks.
In this study, we propose a combined approach that involves the
experimental findings of the spectral changes and the theoretical calculations of the Raman band, with the aim of determining the relationship between the intensity ratio of the D* band to the G band (I
(D*)/I(G)) and the degree of reduction. The spectral analysis of GO and
rGO and the systematic study of a series of thermally reduced GO
synthesized via thermal treatment (100–900 °C) revealed a strong relationship between the I(D*)/I(G) ratio and the C/O atomic ratio. The
atomic vibrational relationships were ascertained through the D* band
assignment based on the density functional perturbation theory (DFPT)
calculations.
The D* band is known to originate from the sp3 orbital, such that
observed in nanocrystalline diamonds with small grain sizes where the
selection rule is relaxed [20], sp3-rich phases [21], and hexagonal
diamonds [22]. Unlike the above-mentioned studies, the origin of the
D* band was postulated and suggested to originate from trans-polyacetylene in the grain boundaries [23]. In this study, we found that the
D* band originated from the vibrations of carbon atoms that were restricted by oxygen-containing groups, as determined by performing the
DFPT simulation; this implies that the D* band intensity is affected by
the remaining oxygen-containing groups.
2.2. Characterization
2. Experimental details
3. Results and discussion
2.1. Preparation of samples
3.1. Comparative analysis of GO and rGO
A series of thermally treated GO (t-GO) was prepared by annealing
the GO (GO-V50, Standard Graphene Inc.) in a furnace at the temperature range of 100–900 °C for 1 h under a vacuum pressure of 10−3
Torr.
The morphologies of GO and rGO (GO-V50, RGO-V50, Standard
Graphene Inc.) were examined by SEM. As can be seen in Fig. 1(a) and
(b), rGO exhibits the wrinkled and folded morphologies caused by
thermal fluctuations after thermal reduction [25]. As another difference
between the two, the color of the aqueous dispersion distinguishes a
brownish-yellow GO solution and a black rGO solution (Fig. 1(c)) [26].
The UV–Vis absorption spectrum of Fig. 1(d), the black line represents
Scanning electron microscopy (SEM) analysis was performed using a
Hitachi S-4800 scanning electron microscope operated at 10 kV.
Ultraviolet–visible (UV–Vis) absorption spectroscopy was performed
with a SHIMADZU UV-1800 spectrophotometer using aqueous solutions
of GO (0.2 mg/ml) and rGO (0.2 mg/ ml). X-ray photoelectron spectroscopy (XPS) was performed using a Thermo Fisher Scientific KAlpha+ spectroscope with an Al K source at full width at half maximum value lower than 0.5 eV. Raman spectra were measured using a
WItec Alpha 300 Raman spectrometer with 1800 lines/mm using a
532 nm laser. The laser power was set as 50µ W after using a 100×
0.9NA objective lens to avoid the laser-induced reduction of GO [24].
The exposure time was 180 s per spectrum. Calibration was performed
using a silicon standard (520 cm−1). X-ray diffraction (XRD) analysis of
the solid powder state was performed using a Bruker D8-Advance X-ray
diffractometer. Fourier transform infrared (FT-IR) spectroscopy was
conducted on a Nicolet iS10 FTIR spectrometer in the attenuated total
reflectance mode. The FT-IR spectra were recorded at room temperature in the spectral range of 650–4000 cm−1.
2.3. Theoretical calculations
The origin of the D* band was determined using the local density
approximation of the DFPT method implemented with the Cambridge
Serial Total Energy Package (CASTEP) code. The computational details
are provided in the Supplementary Information (S5).
2
Applied Surface Science 536 (2021) 147990
A.Y. Lee, et al.
planar sp2 carbons into the tetrahedral sp3 carbons, resulting in the
peak broadening of the XRD peaks (Fig. 4) [40]. As can be seen, the
XRD spectrum of ordered GO exhibits a sharp peak at 11.6°, while that
of the amorphous rGO exhibits a broad peak at 25.8°. The difference in
the width and position of the peaks indicates that the reduction process
caused damage to the graphene plane and augmented the generation of
defects while decreasing the interlayer distances from 0.76 nm to
0.34 nm due to the loss of oxygen-containing groups [41].
GO with – * plasmon peak at 230 nm and n− * shoulder peak at
270 nm. In the red line of rGO, the peak shifted to 270 nm because of
the restoration of the conjugated structure [27]. Fig. 1(e) and (f) show
the Raman spectra of GO and rGO in the spectral range of 1000 cm−1 to
1800 cm−1. The Raman spectra were deconvoluted using Lorentzian
curves, which consist of the first-order Raman modes, namely: D*, D,
D'', G, and D' bands. The D band, which is located at 1330–1350 cm−1,
arises from the defects and disorders in the carbon lattice and the
double resonant processes near the K point of the Brillouin Zone (BZ)
boundary [28]. The G band at 1583 cm−1 corresponds to the Ramanallowed E2g optical phonon [29]. The D'' band at 1500–1550 cm−1, is
related to the amorphous phase and its intensity is inversely related to
the crystallinity [30]. The D' band at 1620 cm−1 corresponds to an
intra-valley resonance with the G band and undergoes splitting due to
impurities [31]. The D* band at a 1050–1200 cm−1 originates from the
sp3 orbital, which is similar to the D* band observed for nanocrystalline
diamonds with small grain sizes [20], sp3-rich phases [21], and hexagonal diamonds [22], disordered graphite lattice [32], polyene [33],
and trans-polyacetylene in the grain boundaries [23]. Based on the
origins of the D and G bands, the I(D)/I(G) ratio can be used to quantify
the defects in carbon materials. The comparative spectroscopic analysis
of GO and rGO reveals significant changes in Raman peak intensities
due to the heat treatment that resulted in a thermal reduction, folding
of structures, impurities, hybridization structures (sp1, sp2, and sp3),
lattice contraction, exfoliation, and defect formation [34]. However,
the conventional I(D)/I(G) ratio does not provide sufficient details to
allow the evaluation of rGO due to the overlapping of the Raman bands
[16]. Furthermore, due to the dispersion of the D band, the I(D)/I(G)
ratio increases with a decrease in laser excitation energy [35]. Additionally, in high-defect density regimes, the intensity ratio decreases
since the numerous amorphous phases of the carbons dampen all the
Raman modes [17].
Another difference in the Raman spectra of GO and rGO is the significant increase in the intensity of the D* band of rGO as compared to
that of GO (Fig. 1(e) and (f)).
We compared the difference in the D* band intensities of GO and
rGO, depending on the fitting of various combinations of Lorentzian
and Gaussian curves (Fig. S1). To confirm the reliability of the fitted
results of the different deconvolutions, we compared three types of
band combinations: five Lorentzian curves, four Lorentzian curves, and
one Gaussian and four Lorentzian curves. These three combinations
listed have low values close to 1 of reduced 2 for fitting the Raman
spectra of carbon materials [36]. The Raman spectra fitted by the
combinations shown in Fig. S1 indicate that the intensity of the D* band
increased after reduction, regardless of the fit combinations.
To prove that the five Lorentzian curves used for fitting the Raman
spectra are suitable, additional Raman scattering measurements were
performed at a different laser excitation wavelength of 633 nm to show
the non-dispersive characteristics of the G band and the shifting of the D
band [37] (Fig. S2 and Table S1).
As shown in Fig. 2, the peak area and peak intensity ratios of the
Raman bands indicate that the differences in both the I(D*)/I(G) ratios
and the area ratios of the D* band to the G band of GO and rGO are
significantly higher than the differences in the area and intensity ratios
other pairs of the bands.
XPS was performed to identify the chemical states of the elements in
GO and rGO; the XPS profiles are presented in Fig. 3. In the XPS spectra
of GO and rGO, the decomposed peaks of sp2 carbon, sp3 carbon, CeO,
* transition appeared at 284.5, 285.2, 286.3, 288, and
C]O, and
290.9 eV, respectively, which are consistent with the results of previous
studies [38]. The atomic percentages of the CeO and C]O in rGO are
weaker than those values of GO due to a decrease in the oxygen-related
components as shown in Table 1; meanwhile the intensity of the peak
corresponding to sp2 species increased, which resulted in a decrease in
sheet resistance [38,39].
The thermal treatment led to the collapse and conversion of the
3.2. Spectral changes of thermally treated GO
To systematically investigate the I(D*)/I(G) ratio, we analyzed the
Raman spectra of GO that was reduced to varying degrees at different
heat-treatment temperatures. Fig. 5 displays the fitted Raman spectra of
GO thermally treated in the temperature range of 100–900 °C. In the
Raman spectra of t-GO annealed above 600 °C (Fig. 5(f)–(i)), the D*
band is more intense than the values at the temperature below 600 °C,
thus it has a relatively high I(D*)/I(G) ratio and the value increases as
the temperature increases. In contrast, the intensity of the G band decreased with increasing annealing temperature. The changes in the
Raman peak intensities are attributed to the thermal reduction process
that involves the removal of hydroxyl groups and the generation of CO
gas [18]. The FT-IR spectra (Fig. S4) confirm the removal of the hydroxyl groups with increasing temperature. To decompose the hydroxyl
group, a carbon source is required to yield CO gas [34].
Fig. 6(a) and (b) show the variations of Raman peak intensity ratios
with temperature. To accurately capture the comparison of conventional I(D)/I(G) and I(D*)/I(G), we plotted the mean and standard deviations of the ratios obtained by measuring Raman spectra at three
random positions. The intensity of the D band in Fig. 6(a) and the intensity of the D* band in Fig. 6(b) were normalized to the G peak intensity in order to plot the Raman intensity ratio against the annealing
temperature. Fig. 6(c) shows the temperature-dependent atomic ratio
measured by XPS results. After determining that the intensity ratio is
more closely related to the C/O ratio, it is observed that the I(D*)/I(G)
ratio is actually associated with the atomic ratio, rather than the I(D)/I
(G) ratio. To show the relationship intuitively, the I(D*)/I(G) ratio was
plotted against the oxygen atomic percentage, carbon-oxygen ratio, and
carbon atomic percentage (Fig. S3(a–c)). The graphs indicate that the
Raman intensity ratio is related to the reduction degree.
As can be seen, the I(D*)/I(G) ratio decreased unexpectedly with an
increase in temperature from 100 °C to 200 °C. Since temperatures
below 225 °C are not high enough to reduce GO [42], it is difficult to
determine whether the Raman spectral changes occurred due to the
removal of the oxygen-containing groups. In the temperature range of
the 100–200 °C, the change in water content affects the vibrations of
the carbon lattice. This is because the evaporation of water molecules
above 100 °C decreases the distance of the carbon interlayer [43],
which in turn interferes with the vibrations of the carbon atoms, resulting to decrease the intensity of the D* band as well as the I(D*)/I(G)
ratio.
3.3. Theoretical calculations of the D* band
The first principle simulation based on DFPT calculations was performed to confirm the existence of the D* band. A vibrational analysis
was performed to determine the vibrations of the atoms that gave rise
to the peak near 1200 cm−1. Fig. 7(b) and (c) show the vibration of GO
with hydroxyl groups attached above and below the graphene plane,
respectively. The arrows represent the vibration vectors. Experimental
results revealed the correlation between the C/O ratio and the intensity
of the D* band above 600 ℃ (Fig. 6(b)) at which the C/O ratio was
approximately 9:1 (Fig. 6(c)). In addition, the FT-IR spectra (Fig. S4)
showed that the change in the concentration of the hydroxyl group
during heating was greater than the changes in concentrations of the
other groups. Furthermore, the conversion of epoxy groups into
3
Applied Surface Science 536 (2021) 147990
A.Y. Lee, et al.
Fig. 2. (a) Peak area ratios and (b) peak intensity (height) ratios of Raman bands of GO and rGO. The black and red dots represent GO and rGO, respectively. Mean
and standard deviations were calculated by measuring Raman spectra at ten random positions. (For interpretation of the references to colour in this figure legend, the
reader is referred to the web version of this article.)
Fig. 3. Deconvoluted C1s peaks of (a) GO and (b) rGO, respectively.
Table 1
The atomic percentage of each component determined from the C 1s peaks of
GO and rGO.
Sample
sp2
sp3
CeO
C]O
pi-pi
GO
rGO
51.27
66.51
1.79
3.21
30.60
12.83
14.53
12.41
1.82
5.05
hydroxyl groups under atmospheric conditions resulted in the presence
of a large number of hydroxyl groups which are stable oxygen-containing groups [44–46]. Therefore, in the DFPT model, GO has hydroxyl
groups and a C/O ratio of 9:1. As shown in Fig. 7(a), under 532 nm
irradiation, a weak Raman peak appeared at around 1200 cm−1, which
was the frequency of interest. There was a discrepancy between the
wavenumber values obtained using theoretical calculations and those
determined via experimental observations, owing to the complicated
structure of real GO. Because of the presence of the hydroxyl groups
that restrict the intact vibrations of the hexagonal structure, the
movement of carbon atoms near the hydroxyl group is weaker than the
movement of the distant carbon atoms. With the reduction of GO, the
hydroxyl group concentration decreased, which resulted in the restoration of the intrinsic vibrational properties of graphene; thus, the
intensity of the Raman peak gradually increased with increasing annealing temperature.
Fig. 4. XRD spectra of GO (top) and rGO (bottom).
4. Conclusions
A comparative analysis of the Raman spectra of GO and rGO was
performed, which showed the difference in the D* band intensity. The
Raman spectra of t-GO were systemically investigated by comparing the
variations in the I(D*)/I(G) ratio with those in the conventional I(D)/I
(G) ratio as a function of the annealing temperature. The results showed
4
Applied Surface Science 536 (2021) 147990
A.Y. Lee, et al.
Fig. 5. Fitted Raman spectra of t-rGO annealed at the temperatures ranging from 100 °C to 900 °C.
Fig. 6. Variations in (a) I(D)/I(G) and (b) I(D*)/I(G) ratios with annealing temperature. The mean and standard deviations of all measurements are shown. (c)
Change in the atomic ratio with annealing temperature determined from the XPS measurement. The black empty squares represent the carbon atomic percentage,
blue empty squares represent the oxygen atomic percentage, and red-filled squares represent the carbon-oxygen ratio.
that that the I(D*)/I(G) ratio is more closely related to the C/O ratio.
The DFPT calculation results indicate that the D* band originates from
the vibration of the carbon atoms restricted by the oxygen-containing
groups. Therefore, the intensity of the D* band is affected by the residual oxygen-containing groups, such as the vaporization of water
molecules at a low temperature and the elimination of oxygen-containing groups at a high temperature. The calculation results help reveal the origin of the D* band, evidencing that the band originates from
the sp3 phase and carbon stretching vibrations, which explains the relationship between the I(D*)/I(G) ratio and the degree of reduction.
Consequently, the D* band can serve as an indicator for the reduction
degree of thermally reduced GO. This approach can not only be used to
measure the quality of GO synthesized by various reduction methods
but also have the potential to be used in general to carry out an accurate
measure of the quality of rGO.
Credit authorship contribution statement
A Young Lee: Formal analysis, Investigation, Data curation,
Writing-original draft, Visualization and Methodology. Kihyuk Yang:
Calculations, Software, and Visualization. Nguyen Duc Anh:
Investigation and Formal analysis. Chulho Park: Formal analysis.
Seung Mi Lee: Calculations and Software. Tae Geol Lee: Validation,
Supervision, Funding acquisition, Writing-review & editing, and
Resources. Mun Seok Jeong: Conceptualization, Validation,
Supervision, Writing-review & editing, Project administration.
5
Applied Surface Science 536 (2021) 147990
A.Y. Lee, et al.
Fig. 7. (a) Raman spectrum of the D* band obtained from DFPT calculations. Schematic of the (b) top and (c) side view showing the vibrations of atoms related to the
D* band. The gray spheres represent the carbon atoms, and the red and white spheres represent the hydroxyl groups (white sphere: hydrogen; red sphere: oxygen).
Declaration of Competing Interest
175–176, https://doi.org/10.1038/nchem.224.
[10] S. Kumar, N. McEvoy, T. Lutz, G.P. Keeley, V. Nicolosi, C.P. Murray, W.J. Blau,
G.S. Duesberg, Gas phase controlled deposition of high quality large-area graphene
films, Chem. Commun. 46 (2010) 1422–1424, https://doi.org/10.1039/b919725g.
[11] C. Virojanadara, M. Syväjarvi, R. Yakimova, L.I. Johansson, A.A. Zakharov,
T. Balasubramanian, Homogeneous large-area graphene layer growth on 6HSiC(0001), Phys. Rev. B – Condens. Matter Mater. Phys. 78 (2008) 1–6, https://doi.
org/10.1103/PhysRevB.78.245403.
[12] J.I. Paredes, S. Villar-Rodil, M.J. Fernández-Merino, L. Guardia, A. MartínezAlonso, J.M.D. Tascón, Environmentally friendly approaches toward the mass
production of processable graphene from graphite oxide, J. Mater. Chem. 21 (2011)
298–306, https://doi.org/10.1039/c0jm01717e.
[13] D.C. Marcano, D.V. Kosynkin, J.M. Berlin, A. Sinitskii, Z. Sun, A. Slesarev,
L.B. Alemany, W. Lu, J.M. Tour, Improved synthesis of graphene oxide, ACS Nano 4
(2010) 4806–4814, https://doi.org/10.1021/nn1006368.
[14] Y. Wang, D.C. Alsmeyer, R.L. McCreery, Raman spectroscopy of carbon materials:
structural basis of observed spectra, Chem. Mater. 2 (1990) 557–563, https://doi.
org/10.1021/cm00011a018.
[15] M.S. Dresselhaus, A. Jorio, M. Hofmann, G. Dresselhaus, R. Saito, Perspectives on
carbon nanotubes and graphene Raman spectroscopy, Nano Lett. 10 (2010)
751–758, https://doi.org/10.1021/nl904286r.
[16] A.A.K. King, B.R. Davies, N. Noorbehesht, P. Newman, T.L. Church, A.T. Harris,
J.M. Razal, A.I. Minett, A new raman metric for the characterisation of graphene
oxide and its derivatives, Sci. Rep. 6 (2016) 1–6, https://doi.org/10.1038/
srep19491.
[17] L.G. Cançado, A. Jorio, E.H.M. Ferreira, F. Stavale, C.A. Achete, R.B. Capaz,
M.V.O. Moutinho, A. Lombardo, T.S. Kulmala, A.C. Ferrari, Quantifying defects in
graphene via Raman spectroscopy at different excitation energies, Nano Lett. 11
(2011) 3190–3196, https://doi.org/10.1021/nl201432g.
[18] S. Claramunt, A. Varea, D. López-Díaz, M.M. Velázquez, A. Cornet, A. Cirera, The
importance of interbands on the interpretation of the Raman spectrum of graphene
oxide, J. Phys. Chem. C 119 (2015) 10123–10129, https://doi.org/10.1021/acs.
jpcc.5b01590.
[19] B. Ma, R.D. Rodriguez, A. Ruban, S. Pavlov, E. Sheremet, The correlation between
electrical conductivity and second-order Raman modes of laser-reduced graphene
oxide, Phys. Chem. Chem. Phys. 21 (2019) 10125–10134, https://doi.org/10.1039/
c9cp00093c.
[20] A. Manea, M.R. Leishman, Competitive interactions between native and invasive
exotic plant species are altered under elevated carbon dioxide, Oecologia 165
(2011) 735–744, https://doi.org/10.1007/s00442-010-1765-3.
[21] R.J. Nemanich, J.T. Glass, G. Lucovsky, R.E. Shroder, Raman scattering characterization of carbon bonding in diamond and diamondlike thin films, J. Vac. Sci.
Technol. A Vacuum, Surfaces, Film. 6 (1988) 1783–1787, https://doi.org/10.1116/
1.575297.
[22] C.P.A.T. Klein, J.G.C. Wolke, J.M.A. De Blieck-Hogervorst, K. de Groot, Calcium
phosphate plasma-sprayed coatings and their stability: an in vivo study, J. Biomed.
Mater. Res. 28 (1994) 909–917, https://doi.org/10.1002/jbm.820280810.
[23] A.C. Ferrari, J. Robertson, Origin of the 1150 − cm−1 Raman mode in nanocrystalline diamond, Phys. Rev. B - Condens. Matter Mater. Phys. 63 (2001)
121405, , https://doi.org/10.1103/PhysRevB.63.121405.
[24] R. Trusovas, K. Ratautas, G. Račiukaitis, J. Barkauskas, I. Stankevičiene, G. Niaura,
R. Mažeikiene, Reduction of graphite oxide to graphene with laser irradiation,
Carbon N. Y. 52 (2013) 574–582, https://doi.org/10.1016/j.carbon.2012.10.017.
[25] X. Shen, X. Lin, N. Yousefi, J. Jia, J.K. Kim, Wrinkling in graphene sheets and
graphene oxide papers, Carbon N. Y. 66 (2014) 84–92, https://doi.org/10.1016/j.
carbon.2013.08.046.
[26] Y. Zhou, Q. Bao, L.A.L. Tang, Y. Zhong, K.P. Loh, Hydrothermal dehydration for the
“green” reduction of exfoliated graphene oxide to graphene and demonstration of
The authors declare that they have no known competing financial
interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
This work was supported by the Nano Material Technology
Development Program (No. 2016M3A7B6908929) of the National
Research Foundation (NRF) funded by the Ministry of Science and ICT,
the Development of Measurement Standards and Technology for
Biomaterials and Medical Convergence funded by the Korea Research
Institute of Standards and Science (KRISS – 2020 – GP2020-0004), and
the Technology Innovation Program (20002486) funded by the
Ministry of Trade, Industry & Energy (MOTIE, Korea).
Appendix A. Supplementary material
Supplementary data to this article can be found online at https://
doi.org/10.1016/j.apsusc.2020.147990.
References
[1] K.S. Novoselov, A.K. Geim, S.V. Morozov, D. Jiang, Y. Zhang, S.V. Dubonos,
I.V. Grigorieva, A.A. Firsov, Electric field in atomically thin carbon films, Science
(80-.) 306 (2004) 666–669, https://doi.org/10.1126/science.1102896.
[2] H. Choi, P.T. Nguyen, J. Bin In, Laser transmission welding and surface modification of graphene film for flexible supercapacitor applications, Appl. Surf. Sci. 483
(2019) 481–488, https://doi.org/10.1016/j.apsusc.2019.03.349.
[3] X. Wei, Y. Guan, X. Zheng, Q. Zhu, J. Shen, N. Qiao, S. Zhou, B. Xu, Improvement on
high rate performance of LiFePO 4 cathodes using graphene as a conductive agent,
Appl. Surf. Sci. 440 (2018) 748–754, https://doi.org/10.1016/j.apsusc.2018.01.
201.
[4] Q. Tan, Z. Kong, X. Chen, L. Zhang, X. Hu, M. Mu, H. Sun, X. Shao, X. Guan, M. Gao,
B. Xu, Synthesis of SnO2/graphene composite anode materials for lithium-ion
batteries, Appl. Surf. Sci. 485 (2019) 314–322, https://doi.org/10.1016/j.apsusc.
2019.04.225.
[5] Y. Fang, E. Wang, Electrochemical biosensors on platforms of graphene, Chem.
Commun. 49 (2013) 9526–9539, https://doi.org/10.1039/c3cc44735a.
[6] E. Fernandes, P.D. Cabral, R. Campos, G. Machado, M.F. Cerqueira, C. Sousa,
P.P. Freitas, J. Borme, D.Y. Petrovykh, P. Alpuim, Functionalization of single-layer
graphene for immunoassays, Appl. Surf. Sci. 480 (2019) 709–716, https://doi.org/
10.1016/j.apsusc.2019.03.004.
[7] N.M.R. Peres, The electronic properties of graphene and its bilayer, Vacuum 83
(2009) 1248–1252, https://doi.org/10.1016/j.vacuum.2009.03.018.
[8] A.K. Geim, K.S. Novoselov, The rise of graphene, in: Nanosci. Technol. A Collect.
Rev. from Nat. Journals, 2009: pp. 11–19. https://doi.org/10.1142/
9789814287005_0002.
[9] E.C.H. Sykes, Surface assembly: graphene goes undercover, Nat. Chem. 1 (2009)
6
Applied Surface Science 536 (2021) 147990
A.Y. Lee, et al.
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
[36]
[37]
tunable optical limiting properties, Chem. Mater. 21 (2009) 2950–2956, https://
doi.org/10.1021/cm9006603.
C. Zhu, S. Guo, Y. Fang, S. Dong, Reducing sugar: New functional molecules for the
green synthesis of graphene nanosheets, ACS Nano 4 (2010) 2429–2437, https://
doi.org/10.1021/nn1002387.
S. Reich, C. Thomsen, Raman spectroscopy of graphite, Philos. Trans. R. Soc. A
Math. Phys. Eng. Sci. 362 (2004) 2271–2288, https://doi.org/10.1098/rsta.2004.
1454.
R. Vidano, D.B. Fischbach, New lines in the raman spectra of carbons and graphite,
J. Am. Ceram. Soc. 61 (1978) 13–17, https://doi.org/10.1111/j.1151-2916.1978.
tb09219.x.
S. Vollebregt, R. Ishihara, F.D. Tichelaar, Y. Hou, C.I.M. Beenakker, Influence of the
growth temperature on the first and second-order Raman band ratios and widths of
carbon nanotubes and fibers, Carbon N. Y. 50 (2012) 3542–3554, https://doi.org/
10.1016/j.carbon.2012.03.026.
A.C. Ferrari, J.C. Meyer, V. Scardaci, C. Casiraghi, M. Lazzeri, F. Mauri, S. Piscanec,
D. Jiang, K.S. Novoselov, S. Roth, A.K. Geim, Raman spectrum of graphene and
graphene layers, Phys. Rev. Lett. 97 (2006) 1–4, https://doi.org/10.1103/
PhysRevLett.97.187401.
R. Al-Jishi, G. Dresselhaus, Lattice-dynamical model for graphite, Phys. Rev. B. 26
(1982) 4514–4522, https://doi.org/10.1103/PhysRevB.26.4514.
B. Dippel, H. Jander, J. Heintzenberg, NIR FT Raman spectroscopic study of flame
soot, Phys. Chem. Chem. Phys. 1 (1999) 4707–4712, https://doi.org/10.1039/
a904529e.
S. Hun, Thermal reduction of graphene oxide, Phys. Appl. Graphene - Exp. (2011),
https://doi.org/10.5772/14156.
S.D.M. Brown, M.S. Dresselhaus, A. Jorio, G. Dresselhaus, Observations of the Dband feature in the Raman spectra of carbon nanotubes, Phys. Rev. B - Condens.
Matter Mater. Phys. 64 (2001) 3–6, https://doi.org/10.1103/PhysRevB.64.073403.
A. Sadezky, H. Muckenhuber, H. Grothe, R. Niessner, U. Pöschl, Raman microspectroscopy of soot and related carbonaceous materials: spectral analysis and
structural information, Carbon N. Y. 43 (2005) 1731–1742, https://doi.org/10.
1016/j.carbon.2005.02.018.
M.J. Matthews, M.A. Pimenta, G. Dresselhaus, M.S. Dresselhaus, M. Endo, Origin of
dispersive effects of the Raman D band in carbon materials, Phys. Rev. B – Condens.
[38]
[39]
[40]
[41]
[42]
[43]
[44]
[45]
[46]
7
Matter Mater. Phys. 59 (1999) 6585–6588, https://doi.org/10.1103/physrevb.59.
r6585.
U. Ramabadran, G. Ryan, X. Zhou, S. Farhat, F. Manciu, Y. Tong, R. Ayler,
G. Garner, Reduced graphene oxide on nickel foam for supercapacitor electrodes,
Materials (Basel). 10 (2017), https://doi.org/10.3390/ma10111295.
B.A. Chambers, M. Notarianni, J. Liu, N. Motta, G.G. Andersson, Examining the
electrical and chemical properties of reduced graphene oxide with varying annealing temperatures in argon atmosphere, Appl. Surf. Sci. 356 (2015) 719–725,
https://doi.org/10.1016/j.apsusc.2015.07.197.
H.C. Schniepp, J.L. Li, M.J. McAllister, H. Sai, M. Herrera-Alonson, D.H. Adamson,
R.K. Prud’homme, R. Car, D.A. Seville, I.A. Aksay, Functionalized single graphene
sheets derived from splitting graphite oxide, J. Phys. Chem. B. 110 (2006)
8535–8539, https://doi.org/10.1021/jp060936f.
M.R. Karim, M.S. Islam, K. Hatakeyama, M. Nakamura, R. Ohtani, M. Koinuma,
S. Hayami, Effect of interlayer distance and oxygen content on proton conductivity
of graphite oxide, J. Phys. Chem. C. 120 (2016) 21976–21982, https://doi.org/10.
1021/acs.jpcc.6b06301.
A. Hussein, S. Sarkar, B. Kim, Low temperature reduction of graphene oxide using
hot-plate for nanocomposites applications, J. Mater. Sci. Technol. 32 (2016)
411–418, https://doi.org/10.1016/j.jmst.2016.02.001.
S. Zheng, Q. Tu, J.J. Urban, S. Li, B. Mi, Swelling of graphene oxide membranes in
aqueous solution: characterization of interlayer spacing and insight into water
transport mechanisms, ACS Nano 11 (2017) 6440–6450, https://doi.org/10.1021/
acsnano.7b02999.
S. Kim, S. Zhou, Y. Hu, M. Acik, Y.J. Chabal, C. Berger, W. De Heer, A. Bongiorno,
E. Riedo, Room-temperature metastability of multilayer graphene oxide films, Nat.
Mater. 11 (2012) 544–549, https://doi.org/10.1038/nmat3316.
P.V. Kumar, M. Bernardi, J.C. Grossman, The impact of functionalization on the
stability, work function, and photoluminescence of reduced graphene oxide, ACS
Nano 7 (2013) 1638–1645, https://doi.org/10.1021/nn305507p.
X. Liu, Y. Wen, B. Shan, K. Cho, Z. Chen, R. Chen, Combined effects of defects and
hydroxyl groups on the electronic transport properties of reduced graphene oxide,
Appl. Phys. A Mater. Sci. Process. 118 (2014) 885–892, https://doi.org/10.1007/
s00339-014-8805-5.