Graphene Nanomaterials

Fabrication, Properties, and Applications

Dharmesh P. Hansora, Satyendra Mishra

• Publisher: Jenny Stanford Publishing
• Year: 2017
• ISBN:
  9781315340883
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Industrial & Technical Chemistry

The development of graphene-related nanomaterials and nanocomposite has shown immense utility in the areas of science, engineering, and technology. These materials include graphene derivatives, graphene-supported inorganic nanomaterials and films, graphene-metal decorated nanostructures, core–shell structures of nanocarbon-graphene, and graphene-doped polymer hybrid nanocomposites. They have been prepared by various methods like chemical vapor deposition, exfoliation of graphite, chemical reduction of GO, silver mirror reaction, catalysis, in situ hydroxylation, and sono sol–gel route.

Chapter 1

Introduction

Nanotechnology has blossomed since more than two decades and also it has proved its importance useful in potential areas [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]. Nowadays, graphene is a emerging star and also a new paradigm of relativistic condensed-matter physics and material science. The graphene’s discovery is an important addition, which has been considered as a world’s thinnest material. Graphene’s derivatives play a significant key role in modern life [19]. The fundamental breakthroughs towards the physical understanding of graphene and graphite were already discussed in the 1940s and 1950s [20, 21].

1.1 Discovery of Graphene Nanomaterials

The word graphene is originated from the Greek word “Graphein” that means to write. Earlier research, focusing on preparation and fundamental properties of nanocarbons (e.g. epitaxial graphene films, nanoribbons and nanopatches), provides a basic fundamental knowledge. Graphene’s research has been successfully capitalised after its first revolution by Novoselov et al. [19, 20, 22, 23] in 2004. Graphenes, being an intriguing or evolution from of 2-dimensional (2D) to 3D topology, have potential properties. These 3D materials can be functionalised by the substituting the carbon atoms with heteroatoms or entire functional groups [19, 21, 24, 25, 26, 27, 28].

Graphene is a layered structure or a one-atom-thick planar nanosheet of sp²-bonded carbon atoms packed in a honeycomb crystal lattice [29] or multi layers of carbon atoms that are densely packed into benzene rings stripped of their hydrogen atoms. This 2D nanocarbon–based conducting nanomaterials (NMs) have exceptional characteristics like electronic property, physical properties, chemical tunability and high crystal quality. Graphene’s research has already shown a profusion of new physics and their potential applications [30]. Graphene is a structural parent of all carbon allotropes including graphite, fullerenes, carbon fibres, nanobuds, nanorings, single walled carbon nanotubes (SWCNTs), double walled CNTs (DWCNTs) and multi-walled CNTs (MWCNTs) [19, 20, 21]. Graphene sheets have types which include single-layer, bilayer and few-layer (<10). Kuilla et al. [25] reported about single-layer graphene sheets and 2D carbon crystals. Functional nanocomposites and nanohybrids of graphene sheets have been researched since past decade. The scientists have synthesised graphene-based nanohybrids with various nanostructures that can be engineered by incorporating dissimilar nanoaparticles (NPs) in a composite form. The various forms of carbon (e.g. diamond, graphite, fullerene, CNTs, graphene and their derivatives), chemically stable metal NPs (e.g. gold, copper), metal oxides NPs (e.g. alumina, silica, zirconia, titania), oxide ceramics (e.g. Al₂O₃, CuO), metal nitrides (e.g. AlN, SiN), metal carbides (e.g. SiC), and functionalised NPs. Graphene has already shown an effective support for the nanostructures and defective carbon sheets. Controlled and easily tunable NPs are used for the rational design of new functional materials and also for the development of quite powerful model systems for different applications. The graphene-based hybrid nanostructures are known to be used for improvement in characteristic properties of the composites.

This chapter provides a basic overview of graphene-related NMs. The primarily emphasis is on the different synthetic strategies that have been pursued so far for the preparation of graphene-based inorganic NPs and graphene-doped polymers, as well as the their concerted effect of the properties of the new hybrid functional NMs-based individual components that will present the special features for potential applications. The prospective applications of these graphene-based hybrid NMs will be presented [61, 62, 63] in next chapter.

1.2 History of Graphene

Graphene is a thermodynamically stable form of carbon NMs and extremely intriguing composition of two individual sp²-hybridised carbon sheets. Scientists have focused to develop hybrid systems made of chemically modified graphene and 3D systems based on the graphene sheet assemblies. Germ and his co-workers, in 2004, observed a single-layer graphene made of atomically thin carbon film, which has received increasing attention and becomes a rapidly rising star on the horizon of materials science and condensed-matter physics [31]. Graphene possesses useful properties such as high values of Young’s modulus (~1.1 TPa), a large theoretical specific surface area (2630 m²/g), and excellent thermal conductivity (~5000 W/m·s). In addition, transport phenomena of graphene has been also reported well, indicating mass less Dirac fermions, a bipolar field effect, room-temperature quantum Hall effect, etc. These performances of graphene family members have attracted important concern in recent years increasing impetus in the field of scientific and technological. These peculiar properties have been harnessed among the numerous methods, and one possible route is to incorporate graphene sheets into hybrid nanocomposites. The easy and low cost synthesis, and also non-toxicity of graphene make it as a promising candidate for technological applications [31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63].

1.3 Types of Graphene-Related Advanced Nanomaterials

1.3.1 Graphene-Based Derivatives

Graphene-based carbon NMs [28, 64, 65] mainly include (i) graphene oxide (GO), (ii) doped graphene (iii) derived graphene nanoribbons (GNRs), (iv) graphane, (v) fluorographene, (vi) graphyne (vii) graphdiyne, (viii) graphone and (ix) porous graphene. Graphene is a semimetal with zero band gap, i.e. conduction and valence bands meet at the Dirac point. A zero band gap can be easily tuned by doping and cutting the 2D graphene into form of 1D GNRs [20, 66]. GO is an oxidised and functionalised derivative and it has been reported as hydrophilic material because it has ability of water dispersion. GO adheres on interfaces due to its lower interfacial energy, so it has been widely used as surfactant for emulsification of organic solvents in water. It has been used for the dispersion of insoluble graphite and CNTs in water. This capability strengthens it for development of graphene and P-conjugated systems–based functional hybrid NMs [66, 67]. Graphane is hydrogenated form of graphene sheet. It is a non-magnetic semiconductor having an energy gap due to hydrogenation. Graphane is a hydrocarbon with a stoichiometry formula unit of CH, i.e. extended 2D polymer form of carbon. It generally adds a wealth to the carbon-based NMs useful for hydrogen storage and nanoelectronic applications. Generally, the hydrogen atoms alternate the directions along with the graphane sheet and transform the carbon lattice from sp² to sp³ hybridisation. Graphane can be easily transformed back into original graphene sheets by annealing process. Fluorographene, with stoichiometric formula of CF, is an another important structure of graphene. Fluorographene has a geometric structure and sp³ bonding configuration similar to graphane with each carbon attached to one fluorine atom. Fluorographene has been used as a solid lubricant for developing the batteries un...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Preface
• 1. Introduction
• 2. Fabrication, Functionalisation and Surface Modification
• 3. Characteristic Properties
• 4. Potential Applications
• 5. Summary
• Index