Gram-scale production of nitrogen doped graphene using a 1,3-dipolar organic precursor and its utilisation as a stable, metal free oxygen evolution reaction catalyst

Article abstract of DOI:10.1039/c7cc04044j

For the first time, a one-step scalable synthesis of a few-layer ～10% nitrogen doped (N-doped) graphene nanosheets (GNSs) from a stable but highly reactive 1,3-dipolar organic precursor is reported. The utilization of these N-doped GNSs as metal-free electrocatalysts for the oxygen evolution reaction (OER) is also demonstrated. This process may open the path for the scalable production of other heteroatom doped GNSs by using the broad library of well-known, stable 1,3-dipolar organic compounds.

Full text of DOI:10.1039/c7cc04044j

View Article Online
View Journal
ChemComm
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: M. K. Bayazit, S.
Moniz and K. Coleman, Chem. Commun., 2017, DOI: 10.1039/C7CC04044J.
Volume 52 Number
1
4
January 2016 Pages 1–216
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
ChemComm
Chemical Communications
www.rsc.org/chemcomm
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 1359-7345
COMMUNICATION
Marilyn M. Olmstead, Alan L. Balch, Josep M. Poblet, Luis Echegoyenet al.
Reactivity differences of Sc
first methanofullerene derivatives of Sc
3
N@C2n (2n
=
68 and 80). Synthesis of the
3
N@D5h-C80
rsc.li/chemcomm

Please do not adjust margins
ChemComm
Page 1 of 4
View Article Online
DOI: 10.1039/C7CC04044J
Journal Name
COMMUNICATION
Gram-scale production of nitrogen doped graphene using a 1,3-
dipolar organic precursor and their utilisation as stable, metal free
oxygen evolution reaction catalysts
Received 00th January 20xx,
Accepted 00th January 20xx
a,b *
b*
c
DOI: 10.1039/x0xx00000x
Mustafa K Bayazit,
Savio J. A. Moniz and Karl S. Coleman
www.rsc.org/
For the first time, a one-step scalable synthesis of a few-layer demonstrated to yield high-quality single layer N-doped graphene
10% nitrogen doped (N-doped) graphene nanosheets (GNSs) films, although relatively high temperatures between 600-800 °C
~
5
from a stable but highly reactive 1,3-dipolar organic precursor is were employed. In order to scale-up the preparation of N-doped
reported. The utilization of these N-doped GNSs as metal-free GNSs for practical applications, novel, cost effective and less labour-
electrocatalysts for the oxygen evolution reaction (OER) is also intensive strategies are required. Considering the broad library of
demonstrated. This process may open the path for scalable well-known 1,3-dipolar organic compounds containing various
production of other heteroatom doped GNSs by using the broad heteroatoms (e.g. nitrogen, sulphur and phosphorous) or their
library of well-known, stable 1,3-dipolar organic compounds.
mixtures, 1,3-dipolar cycloaddition polymerization reactions could
be utilized as a scalable, low-cost method to synthesize heteroatom
containing carbon-based nanostructures. However, to the best of
our knowledge no cycloaddition reaction-based synthetic protocol
has been reported for the preparation of heteroatom doped
Fabrication of nitrogen doped (N-doped) carbon nanomaterials
has received significant interest due to their potential application in
supports for catalysts, membrane technology, sensors and
1
4
a, 6
supercapacitors. Among the N-doped carbon nanomaterials,
graphene or related structures,
although solution-mediated
7
particular consideration has been given to N-doped graphene
nanosheets (N-doped GNSs). For instance, the N-doped GNSs with
Diels-Alder polymerization, cyclodehydrogenation of bianthryl-
8
based linear polymers and the
[2+2] cycloaddition of
9
pyridinic, pyrrolic and/or graphitic
N moieties have been
octafunctionalized biphenylenes were shown to be successful for
the preparation of graphene-like nanostructures.
demonstrated to display higher catalytic activity for the oxygen
reduction reaction (ORR) compared to commercial Pt/C catalysts in
In our previous work we reported that the self-cycloaddition of an
in-situ prepared pyridinium ylide dipole can yield conjugated
fluorescent indolizine structures through the addition of a second
2
applications such as metal–air batteries and fuel cells. It was also
shown that N-doped GNSs are extremely versatile and exhibit high
1
0
reversible capacity, superior rate capability as well as long-term
ylide to the double-bond of pyridine heterocycle. This was shown
to occur at a temperature of 150 °C during the surface modification
of single-walled carbon nanotubes (SWCNTs). Free indolizine
formation in the absence of an additional reactant revealed that the
double bonds in the aromatic ring could act as reactive
dipolarophiles under suitable reaction conditions. This
phenomenon can be extended in order to synthesize conjugated
heterocyclic systems and high molecular weight polymers under
suitable reaction conditions, for example, the [2+2] cycloaddition
1
j
cycling stability. However, there are very few reports of their
utilization as metal-free electrocatalysts for the oxygen evolution
3
reaction (OER). To date, several synthetic strategies including
chemical vapor deposition, arc discharge, and thermal/plasma
treatment have been developed to prepare N-doped GNSs with
4
varying elemental nitrogen compositions and environments. These
approaches usually require special reaction conditions (e.g. plasma,
inert atmosphere, high pressure etc.), only proceed at high
temperatures (800-1000 °C), and use toxic precursors (e.g.
1
1
polymerisation of alkenes. In this respect, phthalazinium-1-olates
can be used as versatile precursors due to their high reactivity and
4
a
chlorinated hydrocarbons, cyanuric chloride etc.). However an
1
2
environmentally benign precursor, chitosan, has also been
stability in air. For example, 3-phenyl-phthalazinium-1-olate can
be readily prepared under ambient conditions with high yields using
phthalic anhydride and phenyl hydrazine derivatives, and can be
1
3
stored for long periods without decomposition. Reactivity and
stability of phthalazinium-1-olates towards conjugated double-
bonds was previously demonstrated under solvent-free conditions
(
220 °C) to introduce nitrogen rich phenylphthalazine groups on the
1
4
SWCNT surface via
a 1,3-dipolar cycloaddition pathway.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 2 of 4
View Article Online
DOI: 10.1039/C7CC04044J
Journal Name
COMMUNICATION
Scheme 1. Formation of N-doped graphene nanosheets via a 1,3-dipolar self-cycloaddition of 3-phenyl-phthalazinium-1-olate. Possible 1,3-
dipole/dipolarophile interactions are anticipated to take place on the electron deficient fused benzene ring, in which the double bonds are
highlighted in red on both the 3-phenyl-phthalazinium-1-olate and likely intermediate structure. Note that the decomposition of both
precursor and oligomeric carbonized products are also expected at 480 °C in air. The blue region shows the possible planar structure. The
orange and black materials in the ceramic boats are 3-phenyl-phthalazinium-1-olate and the resultant N-doped graphene, respectively.
-
1
Herein, we report the first example of the utilization of 1,3-dipolar 2D-band is observed around 2640 cm which is in close agreement
1
5
cycloaddition reactions to fabricate gram-scale N-doped GNSs using with the previously reported few-layer GNSs. The structure of the
a nitrogen rich 1,3-dipole, namely 3-phenyl-phthalazinium-1-olate, as-produced N-doped GNSs was further studied by X-ray diffraction,
as the only precursor via a mild thermal treatment in air. The N- which exhibited
a broad [002] reflection at 21.46° 2θ,
doped GNSs were used as a stable, metal-free catalyst for corresponding to a d-spacing of 0.41 nm (Figure 1b). This increased
electrocatalytic oxygen evolution reaction (OER). In a typical interlayer spacing, compared to pure graphite (0.37 nm), can be
procedure, 3-phenyl-phthalazinium-1-olate containing approxi- attributed to the introduction of surface groups such as nitrogen
mately 12% nitrogen (at%) is carbonized at 480 °C in air to yield N- containing 5-membered heterocycles into the 2D carbon
1
0-11
doped GNSs (Scheme 1). Similar to the previous studies,
N- framework. The other peak at ca. 44.65° 2θ corresponds to the
doped GNSs are believed to be formed following the successive 1,3- [100] in-plane hexagonal atomic arrangement. Transmission
dipolar cycloaddition of 3-phenyl-phthalazinium-1-olate to the electron microscopy (TEM) images show the presence of a 2D,
reactive double-bonds present on an electron deficient fused layered carbon nanomaterial (Figure 1c). The presence of partially
benzene ring at relatively high temperatures, as shown in Scheme transparent sheets suggests that N-doped GNSs can be exfoliated in
1
. Raman spectroscopy has been used extensively to study graphitic amidic organic solvents (e.g. NMP and DMF) which has been shown
−1
3
17
materials, with the D-band at ca. 1350 cm linked to the sp -type to be effective for carbon nanomaterial exfoliation. The TEM
surface defects and can be easily compared to the tangential band image of the N-doped GNSs exhibits some characteristics associated
−1 15
(
G-band) at ca. 1580 cm . The Raman spectra (632.8 nm with the formation of slightly twisted GNSs, which might be related
excitation, 1.96 eV) of the produced carbonaceous material is to the regioselectivity of the cycloaddition polymerisation process,
shown in Figure 1a, which confirms the formation of a graphitic possibly occurring perpendicular to the plane of the 1,3-dipole
D G
material. The N-doped GNSs showed an I /I ratio of 0.68,
attributed to disruption of the graphitic framework in comparison
1
5
to a non-defective graphite surface. However this ratio was
smaller than the previously synthesized N-doped graphene
D G
structures which exhibited a I /I ratio in the range of 0.86 to 0.98
1
6
for different N-doping levels (10.1-5.6 N%). These findings suggest
that the N-doped GNSs produced via the 1,3-dipolar self-
3
cycloaddition polymerisation route contain less sp -type defects. In
fact, surface functionalization of N-doped GNSs, which lead to an
D G
increase in the I /I ratio, are mainly expected as a result of our
synthetic method since the reaction proceeds via a 1-3-dipolar
3
cycloaddition to the double-bonds on the surface. Less sp defects
are sought-after as highly defective N-doped GNSs suffer from
Figure 1 a) Raman spectrum of as-produced N-doped GNSs b) XRD
pattern of as-produced N-doped GNSs c) TEM image N-doped GNS
dispersed in NMP. Black arrows show the twisted regions. d) The
selected area electron diffraction (SAED). e) AFM image with the
inset showing average thickness of N-doped GNS dispersed in NMP.
reduced electron transport on the surface which can limit their
4
a
catalytic performance.
Thus less defective N-doped GNSs
produced by our 1,3-dipolar self-cycloaddition polymerisation route
may be beneficial for catalytic reactions such as ORR/OER since
electron mobility will be improved. In addition, the characteristic
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 2
Please do not adjust margins

Page 3 of 4
Please dCo h ne omt Ca do j um s mt margins
View Article Online
DOI: 10.1039/C7CC04044J
Journal Name
see Scheme 1). Further TEM analysis suggests the formation of 3D-
COMMUNICATION
(
network like layered structures (see ESI Figure S1). Upon further
inspection, the selected area electron diffraction (SAED) displays a
ring-shaped pattern with several diffraction spots, due to the
stacking of crystalline graphitic layers with different angles (Figure
1
8
1
d). AFM height image and the thickness distribution reveal the
emergence of N-doped GNSs with lateral dimensions of ~0.5-3 µm
and approximately 2.5±0.5 nm in thickness (Figure 1e and inset and
ESI Figure S2). The FT-IR spectrum of the N-doped GNSs shows a
Figure 2 a) XPS survey spectrum and b) N 1s XPS spectrum of as-
produced N-doped GNSs.
-1
sharp peak at 1595 cm which is attributed to the C-C stretching
bands present in the graphene framework (see ESI Figure S3). To evaluate the electrocatalytic activities of N-doped GNSs, we
There were no obvious C=O stretchings present in the 1650 to 1800 chose to investigate their activity towards the oxygen evolution
-
1
-1
cm range except a small shoulder at 1657 cm which is due to the reaction (OER), which has recently been the focus of much
3
b
formation of a 6-membered lactam ring following cycloaddition attention. We deposited N-doped GNSs onto both inert carbon
polymerization. Thus the enhanced D-band in the Raman spectrum paper and Nickel foam substrates via a simple drop-casting method
of N-doped GNSs may also be correlated to edge effects rather than using Nafion as a binder (see Experimental section for further
1
9
purely chemical defects. X-ray photoelectron spectroscopy (XPS) details) and tested them in 1M KOH solution (pH 14). RuO2 on
was employed to study the elemental composition of the obtained Nickel foam was used as a comparison. Compared to the uncoated
N-doped GNSs. As expected, the XPS survey spectrum of N-doped carbon paper, the onset for OER in the N-doped GNS was found at
GNSs shows the presence of C, O and N atoms in 73.18, 17.18 and approximately 1.5 V vs RHE and achieved a current density of ca. 55
2
9
.64 atomic per cent (at %) ratios respectively (Figure 2a). The mA/cm at 1.8 V. Similarly, N-doped GNS coated on Nickel foam
percent of atomic nitrogen in the N-doped GNSs (9.64%) was showed an onset of 1.4 V vs RHE and achieved a current of ca. 100
2
comparable to that of the 1,3-dipole precursor (11.74%), which mA/cm at 1.8 V (Figure 3). Upon the application of potentials
indicates almost complete retention of nitrogen atoms after above the onset potential, the evolution of bubbles (oxygen) on the
polymerisation. This correlation provides additional evidence that N-doped GNS electrode and hydrogen bubbles on the Pt counter
the N-doped GNSs are formed via a 1,3-dipolar self-cycloaddition electrode was evident. The small redox peak at ca. 1.4 V in N-doped
polymerization, rather than a thermal decomposition of the dipole GNS is likely due to some impurity nickel oxide species on the Nickel
structure at high temperatures. However, it is worth noting that the foam substrate; the C-V trace from the N-doped GNS electrode is
percentage of oxygen in N-doped GNSs was higher than the 1,3- highly reproducible after scanning several times. The OER activity is
dipole precursor, suggestive of surface oxidation (e.g. oxides) in air. higher than that obtained for N-doped graphene/SWCNT hybrids
2
25
Figure 2b shows the deconvoluted N 1s XPS spectra of N-doped (ca. 7.5 mA/cm at 1.6V vs RHE) but onset and total current a little
GNSs which was fitted by two peaks; they can be attributed to lower than a benchmark, such as RuO . Furthermore, the activity is
2
pyrrolic nitrogen (ca. 400.2 eV) and pyridinic nitrogen (398.7 eV) of the order of that obtained for N-doped graphene nanoribbon
4
a, 20
2
with 62.3 % and 37.7 % contributions, respectively.
Obtaining networks (ca. 15 mA/cm at 1.6 V vs RHE) recently reported, which
pyrrolic nitrogen-rich N-doped GNSs is not surprising since the 1,3- is not surprising as both of these N-doped graphenes possess
dipolar cycloaddition of 3-phenyl-phthalazinium-1-olate mainly electron-withdrawing pyridinic N moieties, which can accept
yields 5-membered pyrazole-type ring structures which confirms electrons (p-type doping) from adjacent C atoms (δ+), facilitating
−
− 3
the previously proposed reaction pathway. Furthermore, the the adsorption of water oxidation intermediates (OH , OOH ). This
deconvoluted C 1s XPS spectrum of the N-doped GNSs exhibits is effectively the rate-determining step for OER in alkaline solution
2
three peaks at ca. 284.7, 285.9 and 288.9 eV, ascribed to sp carbon and thus provides reasoning for OER activity in N-doped graphenes
with C=C bonds (70.57 %), C=N (20.81 %) and the physisorbed in contrast to non-doped carbons that only exhibit high conductivity
oxygen (8.62 %) respectively, consistent with previous reports (see and no appreciable catalytic activity. From DFT studies, the OER
16, 21
ESI Figure S4).
The thermal stability of the synthesised N-doped active sites have been identified in N-doped graphene nanoribbons
GNSs was studied by thermogravimetric analysis (TGA) in both air at the carbon atoms near the nitrogen atom which possess a
and helium (see ESI Figure S5). The TGA curve indicates that the N- minimum theoretical OER overpotential of 0.405 V, which is
2
6
doped GNSs decompose at ca. 545 °C, similar to graphene (500-600 comparable to Pt-containing catalysts. Electrochemical stability of
2
2
23
°
C), indicative of good thermal stability. Consistent with the the N-doped GNS electrodes on both carbon paper and nickel foam
evolution of nitrogen functionalities in carbonaceous materials substrates was also tested under a fixed overpotential (1.7 V vs
2
4
during pyrolysis, N-doped GNSs exhibited only 25% weight loss at RHE) over 24-hours of continued water electrolysis (see ESI Figure
ca. 900 °C in air, which may be linked to the formation of stable S6). The metal-free N-doped GNS catalyst showed excellent stability
quaternary nitrogen moieties during TGA that restricts N-oxide with no obvious loss of current under rapid stirring, which was
formation and subsequent decomposition of the material. employed in order to force the removal of the accumulated oxygen
Furthermore, similar weight loss, attributed to covalently-attached bubbles from the N-doped GNS surface during water electrolysis. In
surface groups and physisorbed oxygen, was observed at ca. 900 °C contrast, the RuO2 displayed inferior stability in KOH, losing over
in helium as well (see ESI Figure S5). The greater rate of weight loss 50% of the activity within the first 10 minutes (see ESI Figure S7)
in helium suggests the formation of quaternary nitrogen moieties is and is a common observation for Ru-based electrocatalysts in
slower than that in air.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
ChemComm
Page 4 of 4
View Article Online
DOI: 10.1039/C7CC04044J
COMMUNICATION
Journal Name
and A. B. Fuertes, ACS Nano, 2014, 8, 5069-5078; iL. Van Nang, N.
Van Duy, N. D. Hoa and N. Van Hieu, Journal of Electronic
Materials, 2016, 45, 839-845; jZ. Xing, Z. Ju, Y. Zhao, J. Wan, Y.
Zhu, Y. Qiang and Y. Qian, Scientific Reports, 2016, 6, 26146.
aL. Qu, Y. Liu, J.-B. Baek and L. Dai, ACS Nano, 2010, 4, 1321-
2
.
1
326; bD. Geng, Y. Chen, Y. Chen, Y. Li, R. Li, X. Sun, S. Ye and S.
Knights, Energy & Environmental Science, 2011, 4, 760-764; cL.
Lai, J. R. Potts, D. Zhan, L. Wang, C. K. Poh, C. Tang, H. Gong, Z.
Shen, J. Lin and R. S. Ruoff, Energy & Environmental Science,
2
012, 5, 7936-7942.
3
4
.
.
aH. B. Yang, J. Miao, S.-F. Hung, J. Chen, H. B. Tao, X. Wang, L.
Zhang, R. Chen, J. Gao, H. M. Chen, L. Dai and B. Liu, Science
Advances, 2016, 2; bD. Guo, R. Shibuya, C. Akiba, S. Saji, T. Kondo
and J. Nakamura, Science, 2016, 351, 361-365.
Figure 3 Current-voltage curves of N-doped GNS dispersed in DMF
and deposited on both carbon paper and Nickel foam together with
aH. Wang, T. Maiyalagan and X. Wang, ACS Catalysis, 2012, 2,
pure carbon paper and Nickel foam and RuO
2
on Nickel foam for the
7
81-794; bP. Bhunia, E. Hwang, Y. Yoon, E. Lee, S. Seo and H. Lee,
oxygen evolution reaction (OER), carried out in 1M KOH (pH 14).
Chemistry – A European Journal, 2012, 18, 12207-12212.
A. Primo, P. Atienzar, E. Sanchez, J. M. Delgado and H. Garcia,
Chemical Communications, 2012, 48, 9254-9256.
V
IV
27
Redox peak for RuO
2
is due to the Ru /Ru redox couple.
5.
2
7
alkaline conditions. Thus the N-doped GNS could be utilised as a
low-cost, metal free stable electrocatalyst for OER and potentially
as a co-catalyst for photocatalytic water oxidation, work of which
iscurrently underway.
6
7
.
.
Y. Z. Xue, B. Wu, Q. L. Bao and Y. Q. Liu, Small, 2014, 10, 2975-
2
991.
A. Narita, X. Feng, Y. Hernandez, S. A. Jensen, M. Bonn, H. Yang, I.
A. Verzhbitskiy, C. Casiraghi, M. R. Hansen, A. H. R. Koch, G. Fytas,
O. Ivasenko, B. Li, K. S. Mali, T. Balandina, S. Mahesh, S. De Feyter
and K. Müllen, Nat Chem, 2014, 6, 126-132.
J. Cai, P. Ruffieux, R. Jaafar, M. Bieri, T. Braun, S. Blankenburg, M.
Muoth, A. P. Seitsonen, M. Saleh, X. Feng, K. Mullen and R. Fasel,
Nature, 2010, 466, 470-473.
In summary, for the first time, a 1,3-dipolar cycloaddition reaction
was tested and proven to be a suitable synthetic technique for
gram-scale production of few-layer 10% N-doped GNSs containing
8
.
3
less sp -type defects, which was isolated as a stable solid under
relatively mild conditions. Photoelectron spectroscopy revealed 9.
F. Schlutter, T. Nishiuchi, V. Enkelmann and K. Mullen,
Angewandte Chemie-International Edition, 2014, 53, 1538-1542.
M. K. Bayazit and K. S. Coleman, Journal of the American
Chemical Society, 2009, 131, 10670-10676.
that N-doped GNSs only possessed pyridinic and pyrrolic nitrogen
1
0.
moieties, the result of
a
1,3-dipolar self-cycloaddition
polymerisation process which can only produce 6- and 5-membered
1
1.
C. Avendano and A. Briceno, CrystEngComm, 2009, 11, 408-411.
C. Najera, J. M. Sansano and M. Yus, Organic & Biomolecular
Chemistry, 2015, 13, 8596-8636.
aA. Bongers, I. Ranasinghe, P. Lemire, A. Perozzo, J.-F. Vincent-
Rocan and A. M. Beauchemin, Organic Letters, 2016, 18, 3778-
rings under the aforementioned experimental conditions. The N- 12.
doped GNSs exhibited good thermal stability up to 545 °C and
1
3.
yielded approximately 75% carbonized material at 900 °C in air, and
could potentially be used in heat resistant coatings and similar
applications. Moreover, the utilisation of N-doped GNSs as efficient
and stable electrocatalysts for OER has been demonstrated, which
opens the path toward their utilisation as metal-free
electrocatalysts for the kinetically and thermodynamically
3
781; bN. Dennis, A. R. Katritzky and M. Ramaiah, Journal of the
Chemical Society, Perkin Transactions 1, 1976, DOI:
0.1039/P19760002281, 2281-2284.
M. K. Bayazit and K. S. Coleman, Chemistry – An Asian Journal,
012, 7, 2925-2930.
1
1
1
4.
5.
2
A. C. Ferrari and D. M. Basko, Nat Nano, 2013, 8, 235-246.
Z.-H. Sheng, L. Shao, J.-J. Chen, W.-J. Bao, F.-B. Wang and X.-H.
Xia, ACS Nano, 2011, 5, 4350-4358.
challenging process of water oxidation, brought about by the 16.
presence of electron-withdrawing pyridinic nitrogen groups. We
1
1
7.
8.
H. C. Yau, M. K. Bayazit, J. H. G. Steinke and M. S. P. Shaffer,
Chemical Communications, 2015, 51, 16621-16624.
Y.-F. Lu, S.-T. Lo, J.-C. Lin, W. Zhang, J.-Y. Lu, F.-H. Liu, C.-M.
Tseng, Y.-H. Lee, C.-T. Liang and L.-J. Li, ACS Nano, 2013, 7, 6522-
6532.
C. R. Herron, K. S. Coleman, R. S. Edwards and B. G. Mendis,
Journal of Materials Chemistry, 2011, 21, 3378-3383.
M. K. Bayazit, L. S. Clarke, K. S. Coleman and N. Clarke, Journal of
the American Chemical Society, 2010, 132, 15814-15819.
C. Zhang, L. Fu, N. Liu, M. Liu, Y. Wang and Z. Liu, Advanced
Materials, 2011, 23, 1020-1024.
further anticipate that this scalable high yielding fabrication process
for N-doped GNSs will pave the way for the development of other
applications that require large amounts of N-doped carbons in
order to be low-cost and sustainable. In addition, other heteroatom
doped GNSs are expected to be synthesised using the library of
well-known 1,3-dipolar organic compounds.
1
2
9.
0.
Acknowledgements
The authors acknowledge funding from EPSRC Grant No. 21.
EP/G007314/1 (M.K.B. and K.S.C.) and EU FP7 4G-PHOTOCAT
2
2
2.
3.
H. Y. Nan, Z. H. Ni, J. Wang, Z. Zafar, Z. X. Shi and Y. Y. Wang,
Journal of Raman Spectroscopy, 2013, 44, 1018-1021.
L. S. Panchakarla, K. S. Subrahmanyam, S. K. Saha, A. Govindaraj,
H. R. Krishnamurthy, U. V. Waghmare and C. N. R. Rao, Advanced
Materials, 2009, 21, 4726-4730.
Grant No. 309636 and EPSRC Grant No. EP/N009533/1 (S.M.).
Notes and references
1
.
aD. H. Deng, K. S. Novoselov, Q. Fu, N. F. Zheng, Z. Q. Tian and X.
H. Bao, Nature Nanotechnology, 2016, 11, 218-230; bC. D. Cress,
S. W. Schmucker, A. L. Friedman, P. Dev, J. C. Culbertson, J. W. 24.
Lyding and J. T. Robinson, ACS Nano, 2016, 10, 3714-3722; cW.
Cai, C. Wang, X. Fang, L. Yang and X. Chen, Applied Physics 25.
Letters, 2015, 106, 253105; dD. W. Chang and J. B. Baek,
Chemistry-an Asian Journal, 2016, 11, 1125-1137; eL. Feng, L. 26.
Yang, Z. Huang, J. Luo, M. Li, D. Wang and Y. Chen, Scientific
Reports, 2013, 3, 3306; fY. Liu, L. Yu, C. N. Ong and J. Xie, Nano 27.
Research, 2016, 9, 1983-1993; gB. Mendoza-Sanchez and Y.
Gogotsi, Advanced Materials, 2016, 28, 6104-6135; hM. Sevilla
J. R. Pels, F. Kapteijn, J. A. Moulijn, Q. Zhu and K. M. Thomas,
Carbon, 1995, 33, 1641-1653.
G.-L. Tian, M.-Q. Zhao, D. Yu, X.-Y. Kong, J.-Q. Huang, Q. Zhang
and F. Wei, Small, 2014, 10, 2251-2259.
M. Li, L. Zhang, Q. Xu, J. Niu and Z. Xia, Journal of Catalysis, 2014,
314, 66-72.
M. Gao, W. Sheng, Z. Zhuang, Q. Fang, S. Gu, J. Jiang and Y. Yan,
Journal of the American Chemical Society, 2014, 136, 7077-7084.
4
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins