This document summarizes methods for synthesizing nitrogen-sulfur doped graphene for hydrogen storage. CVD (chemical vapor deposition) and the DVD burner method are proposed for graphene synthesis. CVD involves using a copper foil substrate, annealing in hydrogen and argon, and depositing using methane and hydrogen. The DVD burner method applies a graphite oxide and plastic film to a DVD, which is then inserted into a DVD drive to chemically reduce the graphite oxide to graphene using the laser. Nitrogen-sulfur doping of the graphene is achieved by heating dimethyl sulfoxide and sodium hydroxide under nitrogen gas flow to form a black cake-like material. These doped graphene materials show potential for efficient hydrogen storage.

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ScienceDirect
Procedia Materials Science (2015) 000–000
www.elsevier.com/locate/procedia
2211-8128 © 2015 The Authors. Published by Elsevier Ltd.
Peer-review under responsibility of the International Conference on Nanomaterials and Technologies (CNT 2014).
2nd International Conference on Nanomaterials and Technologies (CNT 2014)
Synthesis of N-S Doped Graphene for Hydrogen Storage
Sandeep Pal1*
, Akriti Agrawal1
, S K Nippani2
and Gagan Anand2
1
Student, Department of Mechanical Engineering, University of Petroleum & Energy Studies, Bidoli,Via
PremNager Dehradun,Pin-248007, India
2
Department of Physics, College of Engineering Studies, University of Petroleum & Energy Studies, Bhidoli, Via
Prem Nagar, Dehradun,Pin-248007, India
Abstract
Doping is a common and effective approach to tailor semiconductor properties. Theoretical studies predicted that
doping graphene with nitrogen and sulphur can tailor its electronic properties and chemical reactivity. Hydrogen as
an environment friendly fuel is a strong contender for fossil fuel based auto fuel. But the major stumbling block in
realizing this is the risk involved in transporting hydrogen due to the risk of fire hazard owing to wider limits of in
flammability. Hence, it is important to develop efficient hydrogen storage devices for storing and transporting
hydrogen safely. Graphene in its original form do not have good hydrogen storage capacity but synthesized
graphene are reported to be the best method for hydrogen storage since (Nitrogen–sulphur) doped graphene exhibit
good electrical conductivity, long durability and high selectivity.CVD (Chemical vapour deposition)method is also
considered one of the best method for synthesis of grapheme.
© 2015 The Authors. Published by Elsevier Ltd.
Peer-review under responsibility of the International Conference on Nanomaterials and Technologies (CNT 2014).
Keywords: Doping, Graphene, CVD, Durability
* Sandeep Pal Mob- 08979405519
Email id- Sandy.pal18@gmail.com

2. 2 Author name / Procedia Materials Science 00 (2015) 000–000
1. Introduction:
Graphene is a nearly transparent material that has the highest room temperature electrical conductivity of any known
substance. Graphene is a single atomic layer thick thin sheet of ideally sp2
bonded carbon atoms that are densely
packed in a honeycomb crystal lattice. Graphene was first experimentally realized by mechanical exfoliation of
graphite using scotch tape Bhaviri pudisreeka et.al (1994) but micromechanical exfoliation yields small samples of
graphene useful only for fundamental study. Another method of epitaxial growth is to heat silicon carbide to high
temperatures (> 1100_C) to reduce it to graphene. The size of graphene crystal is dependent upon the size of the Sic
(Silicon carbide) substrate used. High-quality sheets of few layer graphene exceeding 1 cm2
in area have been
synthesized via CVD (Chemical Vapour Deposition) on thin nickel layers. Recently gram-scale production of
graphene has been reported by reduction of ethanol using sodium metal, followed by pyrolysis of the ethoxide
product, and washing with water to remove sodium salts. Use and handling of sodium metal make the process
complicated and require precautionary measures and expert handling. Here, we report on a large-scale chemical
synthesis of graphene sheets by a relatively safer and easier method using an autoclave.
Table 1 – Properties of graphene
Graphene Properties
Modulus 1 Tpa
Strength 130 Gpa
Electrical conductivity
Surface area
600 S/cm
2600 m2
/gm
Hydrogen as an environment friendly fuel is a strong contender for fossil fuel based auto fuel. But the major
stumbling block in realizing this is the risk involved in transporting hydrogen due to the risk of fire hazard owing to
wider limits of in flammability. Hence, it is important to develop efficient hydrogen storage devices for storing and
transporting hydrogen safely. Graphene in its original form do not have good hydrogen storage capacity but
synthesized graphene are able to store hydrogen. Some of the methods are listed below:-
1.1 Bottom up Graphene (KumardilipSingh)
1. Chemical vapour deposition
2. DVD burner method
3. Epitaxial growth (Can be prepared by simply heating and cooling down a Sic crystal)
4. Solvothermal
5. Scotch tape method (Graphene is detached from a graphite crystal using adhesive tape)
1.2 Top down Graphene
1. Micromechanical cleavage (Use of an ultra-sharp single crystal diamond wedge to cleavage a highly
ordered pyrolytic graphite sample to generate the graphene layers)
2. Arc cleavage (Involve the use of a high current between a graphite anode and graphite cathode in a
chamber filled with hydrogen and helium gas, costlier method)
3. Chemical synthesis through oxidation of graphite
4. Thermal exfoliation and reduction
5. Electrolytic exfoliation

3. Author name / Procedia Materials Science 00 (2015) 000–000 3
Of which heteroatom’s substituted graphene, anchored with noble metals being reported to be a highly effective for
hydrogen storage .The heteroatom-doped graphene suggest the potential to be employed as an effective, alternative
chemical material by demonstrating performance comparable to that of the expensive platinum catalyst used for the
cathode of fuel cell batteries(Tuba Oznuluer, 1995).So among the methods listed above chemical vapour deposition
and DVD burner method are proposed to be used for graphene synthesis.
A significant advance toward achieving practical applications of graphene as a two –dimensional material in Nano
electronics would be provided by successful synthesis of both n-type and p-type doped graphene. However, reliable
doping and a thorough understanding of carrier transport in the presence of charged impurities governed by ionized
donors or acceptors in the graphene lattice are still lacking. Here, we report experimental realization of few- layer N-
doped (Nitrogen doped) graphene sheets by chemical vapour deposition of organic molecule 1, 3,5-triazine on Cu
(Copper) metal catalyst. When reducing the growth temperature, the atomic percentage of nitrogen doping is raised
from 2.1% to 5.6%.With increasing doping concentration-doped graphene sheet exhibits a crossover from p-type to
n-type behaviour accompanied by a strong enhancement of electron – hole transport asymmetry, manifesting the
influence of incorporated nitrogen impurities. In addition, by analysing the data of X-ray photoelectron
spectroscopy, Raman spectroscopy, and electrical measurements of prepared DVD based graphene, we show that
pyridinic and pyrrolic N impurities play an important role in determining the transport behaviour of carriers in our
doped N doped graphene.Bo Quan etal. (2014).
2. Experimental work :
2.1 Chemical vapour deposition:
CVD can be done using either LPCVD (Low pressure chemical vapour deposition) or APCVD (Atmospheric
pressure chemical vapour deposition) but using LPCVD will be better.
 Heater: graphite electrodes placed at the top and bottom with a separating distance of 10 cm.
 Chamber: in chamber quartz reactor.
 IR detector: temperature measurement
 Substrate: A cupper foil (3 inch * 1 inch) was placed on the bottom heater
 Annealing: by H2 (Hydrogen) and Ar (Argon) (increase Cu grains) for 20-30 min because it would remove
the residual copper oxide and smoothen the surface.
 Deposition: using CH4 (Total pressure 625 torr) and H2 as precursor and cooling rapidly under Ar.
Fig 1: CVD process representing the different controller system.

4. 4 Author name / Procedia Materials Science 00 (2015) 000–000
Fig 1: CVD process using copper foil as a catalyst
Before, we tried to do the roll to roll process because it was an ideal production choice when a very low cost per unit
area of deposition is required. In this process commercial ethylene –Vinyl acetate copolymer coated transparent
polyethylene terephthalate were used as a target surface. At a temperature of 150 ˚c, the sheets were pressed together
with hot rollers to form a double sided PET (Polyethylene terephthalate) sheet. The EVA layer plays a role of
viscose between FLG and PEG. After the hot rolling step the sheet was passed into cold rollers at room temperature.
The purpose of the cold rolling step is to separate the PET layers from the nickel surface in a uniform manner with a
controlled constant rolling speed. Figure: 3 representing the whole process. But during this process the arrangements
of the chemical were more difficult, so basically we preferred for the Low pressure chemical vapour deposition
Zhen-Yu Juang (2007).
Fig 2: Roll to roll process by chemical vapour deposition
2.2 DVD burner process:
The process starts with graphite oxide because it can be suspended in water. This allows evenly distributing the
substance on plastic surface. Note the use of optical discs. The second part of process involves hitting the dried layer
of graphite oxide with a laser. It can be done with consumer DVD drive. The result is graphene that can be used in
circuits and may have potential as a fantastic super- capacitor Zhen-Yu Juang et al. (2007)
Figure-4 representing the DVD burner procedure for the synthesis of graphene, We take a DVD and apply a layer
of plastic, followed by a film of graphite oxide, then inserted the DVD into a standard DVD drive, so that the in-
built laser chemically reduces the graphite oxide to graphene. Having removed the disc, we peel off the plastic,

5. Author name / Procedia Materials Science 00 (2015) 000–000 5
which is then coated in graphene, and cut it into whatever shapes we desire K Novoselo et al. (2006)
Fig 3: DVD process for the synthesis of graphene
3. Procedure for Synthesis of Heteroatom doped Graphene:
DMSO (Dimethyl sulfoxide), the S-containing organic molecule, was heated with NaoH (Sodium hydroxide) under
N2 gas flow. The mixture was brought to a boil, and maintained the boil with reflux. Under the condition, the
colourless liquid became dark brown. Finally, black cake-like Materials were obtained and washed using deionised
water then dried in an oven. Two-dimensional sheet-like structures were obtained, which were formed with carbon
and sulphur atoms. The surface morphology of the S-doped graphene was analysed by using AFM (Atomic Force
Microscopy). The AFM images showed crumpled silk veil-like structures with thickness of around 1 nm. With 50
ml of DMSO, more than 1.0 g of product per batch was obtained. We believe that this process could be scaled up for
larger synthetic yields. To demonstrate that the heteroatom-containing organic molecules it could be converted into
heteroatom-doped graphene, DMF was chosen to produce N-doped graphene, to represent N-containing molecules.
Roughly 2.6 g of product was obtained from 50 mL of DMF. Pristine solvothermal graphene was also prepared
using methanol as a precursor. Inclusions of nitrogen enhance significantly thermal stability of graphene on nickel
M El-Kady
In the present work, the hydrogen storage properties of N-GNP (Nitrogen-doped graphene Nano platelets) and Pd/N-
GNP (Palladium decorated nitrogen-doped graphene Nano platelets) have been investigated. The results show that
hydrogen uptake capacity of nitrogen doped graphene Nano platelets and palladium decorated nitrogen doped
graphene Nano platelets at pressure 32 bars and temperature 25 degrees C is 0.42 wt% and 1.25 wt% respectively.
The dispersion of palladium nanoparticles increases the hydrogen storage capacity of nitrogen doped graphene Nano
platelets by 0.83 wt%. This may be due to high dispersion of palladium nanoparticles and strong adhesion between
metal and graphene Nano platelets over the surface of N-GNP, which enhances the spill over mechanism. Thus, an
increase in the hydrogen spill over effect and the binding energy between metal nanoparticles and supporting
material achieved by nitrogen doping has been observed to result in a higher hydrogen storage capacity of pristine
GNP (Graphene Nano platelets).

6. 6 Author name / Procedia Materials Science 00 (2015) 000–000
Fig 4: Representing the microstructure obtained after synthesis
N-Doped graphene can also be prepared by nitrogen plasma treatment process. N Graphene has shown better
electrode capability than graphene.

7. Author name / Procedia Materials Science 00 (2015) 000–000 7
3.2: Nitrogen doped Graphene:
3.2.1 Reagents and buffer electrolyte solution
N-doped graphene prepared by thermal reduction of graphite oxide S.Park (2001) and the chemicals were purchased
from the different standard companies for the preparation of N- Doped graphene. For electrolytic experiments the
supporting electrolytes were 0.1 M KCl or NaPbs (Sodium phosphate buffer saline). Then the polymerization was
carried out in 0.025M.
3.2.2 Functionalization of N-Graphene
Nitrogen doped graphene was received either in 3M HNO3 (Nitric acid) or in 7M KOH(Potassium hydroxide). For
the acidic treatment, the graphene or graphite powder was stirred for 12 hr. while for the treatment with the base
stirring was done for 4 hours followed by another 20 hours static soaking in ambient condition. The functionalized
were then washed and filtered until the solution becomes neutral. The material obtained was dried at approximately
60 ˚c overnight. In this way we obtained HNO3 nitrogen doped graphene. Due to the fact that HNO3 treatment of
nitrogen doped graphene was detrimental, the dispersion not being homogeneous. Both functionalized and
nonfunctionalised nitrogen doped graphene were dispersed in 1% Acetic acid to form 0.1% dispersion. The solution
was sonicated for 1 hour. J.s bunch et al. (2007)
4. Conclusion:
Several methods were found to be best for the synthesis of graphene or even for the heteroatom doped graphene but
our aim was the method to be best for the hydrogen storage and its transportation as it is explosive, so we focused
basically on the two methods chemical vapour deposition and DVD burner method so that we could synthesize it
and provide hydrogen a better storage and its transportation, after synthesis characterization part should also be
done. We are still on the procedures, not yet so successful.
Acknowledgement:
We wish to express heartfelt gratitude towards the Campus director of UPES, Dr. Shrihari, for giving us an
opportunity to work in this esteemed organization that in spite of being extraordinarily busy with his duties, took
time out to hear, guide and keep me on the correct path.
Our special thanks to Dr. G.Gopalakrishanan (Associate Professor) .Without his continuous guidance and support,
this project would not have been possible.
It is our glowing feeling to place on record my best regards, deepest sense of gratitude to Miss. Sunu, Mr.Rohit
Sharma (PhD Research Scholars) for their judicious and precious guidance which were extremely valuable for our
study both theoretically and practically. Lastly, we thank almighty, our parents for their constant encouragement
without which this assignment would not be possible.

8. 8 Author name / Procedia Materials Science 00 (2015) 000–000
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