Synthesis of graphene

Int Nano Lett (2016) 6:65–83 DOI 10.1007/s40089-015-0176-1 REVIEW Synthesis of graphene Md. Sajibul Alam Bhuyan1 • Md. Nizam Uddin1 • Md. Maksudul Islam2 • Ferdaushi Alam Bipasha3 • Sayed Shafayat Hossain1 Received: 23 March 2015 / Accepted: 13 December 2015 / Published online: 9 February 2016 Ó The Author(s) 2016. This article is published with open access at Springerlink.com Abstract Graphene, a two-dimensional material of sp2 hybridization carbon atoms, has fascinated much attention in recent years owing to its extraordinary electronic, optical, magnetic, thermal, and mechanical properties as well as large specific surface area. For the tremendous application of graphene in nano-electronics, it is essential to fabricate high-quality graphene in large production. There are different methods of generating graphene. This review summarizes the exfoliation of graphene by mechanical, chemical and thermal reduction and chemical vapor deposition and mentions their advantages and disadvantages. This article also indicates recent advances in controllable synthesis of graphene, illuminates the problems, and prospects the future development in this field. Keywords Chemical vapor deposition (CVD)
Epitaxial
Mechanical exfoliation
PECVD reduction graphene oxide (RGO)
Unzipping method & Md. Sajibul Alam Bhuyan Md. Maksudul Islam Ferdaushi Alam Bipasha 1 Department of Mechanical Engineering, Khulna University of Engineering and Technology, Khulna 9203, Bangladesh 2 Department of Industrial Engineering and Management, Khulna University of Engineering and Technology, Khulna 9203, Bangladesh 3 Department of Mechanical Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh Introduction Carbon is a ubiquitous material that has been ever found whereas the epoch making material graphene is also an allotropy of carbon. Actually graphene is a two-dimensional, single-layer sheet of sp2 hybridized carbon atoms and has arrested enormous attention and research motives for its versatile properties. In sp2 hybridized bond, the inplane rC–C bond is one of the strongest bonds in materials and the out-of-plane is p bond, which imparts to a delocalized network or array of electrons resulting electron conduction by providing weak interaction among graphene layers or between graphene and substrate. Graphene is a material which has a large theoretical specific surface area (2630 m2g-1), high intrinsic mobility (200,000 cm2 v-1s-1), [1, 2] high Young’s modulus (*1.0 TPa) [3] and thermal conductivity (*5000 Wm-1K-1), [4] and its optical transmittance (*97.7 %) and good electrical conductivity merit attention as well as ability to with stand current density of 108 A/cm2 [5], for applications such as for transparent conductive electrodes [6, 7] among many other potential applications. However, its applicability cannot be effectively realized unless superficial techniques to synthesize high-quality, large-area graphene are developed in a cost effective way. Besides, a great deal of effort is required to develop techniques for modifying and opening its band structure so as to make it a potential replacement for silicon in future electronics. Graphene has been experimentally studied for over 40 years [8–14] and measurements of transport properties in micromechanically exfoliated layers [15], of graphene grown on (SiC) [16], large-area graphene grown on copper (Cu) substrates [17], as well as a variety of studies involving the use of chemically modified graphene (CMG) to make new materials [12–21]. 123 66 Int Nano Lett (2016) 6:65–83 The basic building blocks of all the carbon nanostructures are a single graphitic layer that is covalently functionalized sp2 bonded carbon atoms in a hexagonal honeycomb lattice which forms 3D bulk graphite, when the layers of single honeycomb graphitic lattices are stacked and bound by a weak van der Waals force. When the single graphite layer forms a sphere, it is well known as zerodimensional fullerene; when it is rolled up with respect to its axis, it forms a one-dimensional cylindrical structure called a carbon nanotube; and when it exhibits the planar 2D structure from one to a few layers stacked, it is called graphene. One graphitic layer is well known as monoatomic or single-layer graphene and two and three graphitic layers are known as bilayer and tri-layer graphene, respectively. More than 5 layer up to 10 layer graphene is generally called few layer graphene, and *20–30 layer graphene is referred to as multilayer graphene, thick graphene, or nanocrystalline thin graphite [22]. Synthesis of graphene Synthesis of graphene refers to any process for fabricating or extracting graphene, depending on the desired size, purity and efflorescence of the specific product. In the earlier stage various techniques had been found for producing thin graphitic films. Late 1970’s carbon precipitated in the form of thin graphitic layers on transition metal surfaces [24, 25]. In 1975, few-layer graphite was synthesized on a single crystal platinum surface via chemical decomposition methods, but was not designated as graphene due to a lack of characterization techniques or perhaps due to its limited possible applications [26]. In those periods, their electronic properties never were investigated because of the difficulty in isolating and transferring them onto insulating substrates. But in the late 90’s Ruoff and co-workers tried to isolate thin graphitic flakes on SiO2 substrates by mechanical rubbing of patterned islands on HOPG (Highly Oriented Pyrolytic Graphite) [13]. However there was no report on their electrical property characterization. Using a similar method this was later achieved in 2005 by Kim and co-workers and the electrical properties were reported [27]. But the real prompt advancement in graphene research began after Geim and co-workers first published their work of isolating graphene on to SiO2 substrate and measuring its electrical properties. After discovery of graphene in 2004 various techniques were developed to produce thin graphitic films and few layer graphene. The experimental evidence of 2D crystals came in 2004 [15] and 2005 [28] when thin flakes of graphene and other materials molybdenum disulphide, niobium diselenide and hexagonal boron nitride were first exfoliated from their bulk counterparts (Fig. 1). But 123 Fig. 1 Mother of all graphene forms. Graphene is a 2D building material for carbon material of all other dimensionalities. It can be wrapped up into 0D buckyballs, rolled into 1D nanotubes or stacked into 3D graphite [23] graphene was first obtained in the form of small flakes of the order of several microns through mechanical exfoliation of graphite using scotch tape [4, 9]. Although this method gives the highest quality graphene but for mass production, fabrication method is needed that can synthesize wafer scale graphene. In recent years, various techniques have been established for gra (...truncated)