Electrochemical preparation of free-standing few-layer graphene through oxidation–reduction cycling

doi:10.1016/j.cej.2011.03.078

Chemical Engineering Journal

Volume 171, Issue 1, 15 June 2011, Pages 340-344

https://doi.org/10.1016/j.cej.2011.03.078 Get rights and content

Abstract

Free-standing few-layer graphene (FFG) were electrochemical-exfoliated from a graphite column via oxidation–reduction cycling (ORC). FFG with the width up to 500 nm, and length up to 800 nm were successfully obtained. The atom layers, crumpled morphology and scroll that concerned with structure defect of FFG were found through transmission electron microscope (TEM). The presence of defects on FFG was proved by Raman spectroscopy, and the surface chemistry informations about oxygen-containing groups were collected from XPS and FTIR data. For the potential applications of this FFG, the capability of electron transfer was studied by AC impedance and the electro-catalytic oxidation of nicotinamide adenine dinucleotide (NADH) was investigated. The results showed that this method can provide valuable protocol for preparation free-standing few-layer graphene, which may facilitate both its synthesis and applications.

Introduction

It is well known that carbon materials, such as diamond and graphite, have been used widely in many fields due to their various physical properties with the allotropic form. The discovery of C₆₀ [1] as a novel carbon nanoscale material paved the way for novel potential applications. Nowadays, graphene, a two-dimensional nano-carbon material, composed of layers of carbon atoms forming six-membered rings, has became one of the most exciting materials being investigated for the needs of both academic curiosity and potential applications. Due to its attractive properties, such as high mobility of charge carriers [2], unique transport performance [3], high mechanical strength [4], and extremely high thermal conductivity [5], graphene have been used in electronics [6], composite materials [7], sensors [8], [9], energy storage/conversion [10], [11], [12] and other applications. Consider that so many applications have been developed, it is rational for people to recognize that high quality graphene materials with different (mono-, bi-, or few-) layer numbers needs to be obtained first according to the application requirements.

For the preparation of graphene materials, several methods have been developed: (1) micromechanical cleavage [2]; (2) epitaxial growth via ultra-high vacuum graphitization [13]; (3) chemical synthesis through oxidation of graphite [14], [15]; (4) chemical vapor deposition (CVD) growth of graphene [16], [17] and (5) electro-chemical exfoliation of graphite [18], [19]. Nevertheless, the existing methods, except electrochemical methods, usually involve complex processes, expensive starting materials (such as ionic liquid) or employs hazardous chemicals (e.g., hydrazine) as reductants. The electrochemical exfoliation is a “green synthesis” method that possesses the advantages of simple, low-lost, nonpolluting and substrate free, which has been receiving much attention.

Herein we present an easy-handling, low-cost and low working-potential electrochemical preparation method for FFG based on ORC. The as-prepared FFG sheets can easily be isolated from supporting electrolyte solution and exhibit potential applications in electrochemical bio-sensor design.

Section snippets

Materials

The high-purity graphite column was obtained from China National Medicines Shenyang Co. Ltd., Quinine sulfate was obtained from Fluka, Dimethyl Formamide (DMF), H₂SO₄, Na₂SO₄, Na₂HPO₄ and NaH₂PO₄ were obtained from Beijing Chemical. Co., Ltd. All other chemicals were at least analytical grade. The water used was ultra-pure water produced through a Milli-Q system. Phosphate buffer solution (PBS) (Na₂HPO₄ + NaH₂PO₄) and all other solutions were prepared with the water purified through a Milli-Q

Results and discussion

Fig. 1 shows the tapping mode AFM image of the electrochemical exfoliated FFG. From the image, flake-like nano-sheets with width and length of up to 500 nm and 800 nm can be found. The thickness of the nano-sheets is about 1.0 nm, which is three times larger than the theoretical thickness of a perfectly flat sp²-carbon-atom network (∼0.3 nm) [20]. It is rational for us to deduce that the nano-sheet being investigated is few-layer graphene containing 3 atom layers.

The FFG samples were transferred to

Conclusions

Simply via an ORC procedure, FFG can be electrochemical-exfoliated from a graphite column successfully. The as-prepared FFG possesses the advantages of good conductivity, defects, few oxygen-containing groups and the electro-catalytic ability to the oxidation of NADH. The method presented here can provide valuable protocol for preparation FFG, which may facilitate both its synthesis and applications.

Acknowledgements

This work was supported by Jilin Provincial Science and Technology Development Foundation (20090151) and the Undergraduate Innovation Research Program of Northeast Normal University.

References (30)

G.X. Wang et al.
Highly efficient and large-scale synthesis of graphene by electrolytic exfoliation
Carbon
(2009)
H.X. Zhang et al.
Fabrication and characterization of few-layer graphene
Carbon
(2010)
A.W. Musumeci et al.
A comparative study of single-walled carbon nanotube purification techniques using Raman spectroscopy
Spectrochim. Acta A
(2008)
L. Agüí et al.
Poly-(3-methylthiophene)/carbon nanotubes hybrid composite-modified electrodes
Electrochim. Acta
(2007)
M. Zhou et al.
Highly ordered mesoporous carbons as electrode material for the construction of electrochemical dehydrogenase- and oxidase-based biosensors
Biosens. Bioelectron.
(2008)
H.W. Kroto et al.
C₆₀: Buckminsterfullerene
Nature
(1985)
K.S. Novoselov et al.
Electric field effect in atomically thin carbon films
Science
(2004)
H.B. Heersche et al.
Bipolar supercurrent in graphene
Nature
(2007)
C. Lee et al.
Measurement of the elastic properties and intrinsic strength of monolayer graphene
Science
(2008)
A.A. Balandin et al.
Superior thermal conductivity of single layer graphene
Nano Lett.
(2008)

X.L. Li et al.

Chemically derived, ultrasmooth graphene nanoribbon semiconductors

Science

(2008)

S Stankovich et al.

Graphene-based composite material

Nature

(2006)

F. Schedin et al.

Detection of individual gas molecules adsorbed on graphene

Nat. Mater.

(2007)

C.S. Shan et al.

Direct electrochemistry of glucose oxidase and biosensing for glucose based on graphene

Anal. Chem.

(2009)

E.J. Yoo et al.

Large reversible Li storage of graphene nanosheet families for use in rechargeable lithium ion batteries

Nano Lett.

(2008)

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Electrochemical preparation of free-standing few-layer graphene through oxidation–reduction cycling

Abstract

Introduction

Section snippets

Materials

Results and discussion

Conclusions

Acknowledgements

Carbon

Carbon

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Electrochim. Acta

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C60: Buckminsterfullerene

Nature

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Science

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C₆₀: Buckminsterfullerene