Graphene and Graphene Oxide: Synthesis,

Properties,and Applications

Presented By: Sheama Farheen Savanur

Introduction

Graphene is an exciting material. [ 1 ] It has a large theoreticalspecific surface area (2630 m 2 g − 1 ), high intrinsic mobility(200 000 cm 2 v − 1 s − 1 ), [ 2 , 3 ] high Young’s modulus ( 1.0 TPa) ∼[ 4 ]and thermal conductivity ( 5000 Wm − 1 K − 1 ), [ 5 ] and its optical∼transmittance ( 97.7%) and good electrical conductivityamong many ∼other potential applications

Propertiesa)Morphology and Structure

The graphene honeycomb lattice is composed of two equivalent sub-lattices of carbon atoms bonded together with σ bonds.

Each carbon atom in the lattice has a π orbital that contributes to a delocalized network of electrons.

freely suspended graphene has ‘intrinsic’ ripples, observed by transmission electron microscopy (TEM) studies.

The microscopiccorrugations (Figure 1b ) were estimated to have a lateral dimension of about 8 to 10 nm and a height displacement of about 0.7 to 1 nm

Ripples can be induced, [ 40 ] suggesting that the local electrical and optical properties of graphene could be altered through ‘ripple-engineering’ for possible application in devices.

Apart from ‘intrinsic’ corrugations, graphene in real 3D space can have other ‘defects,’ including topological defects (e.g., pentagons, heptagons, or their combination), vacancies edges/cracks, adsorbed impurities, and so on

TEM images with a stated sub-Ångstrom resolution showed that both ‘armchair’ and ‘zigzag’ confi gurations could be formed during the edge reconstruction and ‘zigzag’ edges were observed to be particularly stable under electron irradiation at 80 kV acceleration voltage.

b) Electronic Properties

c) Mechanical Properties

The mechanical properties of monolayergraphene including the Young’s modulusand fracture strength have been investigated by atomic force microscopy (AFM)It was reported thatdefect-free graphene has a Young’s modulusof 1.0 TPa and a fracture strength of 130 GPa.