A new era in nanotechnology : Graphene the new horizon

2^nd International Conference and Exhibition on Materials Science & Engineering

October 07-09, 2013 Hampton Inn Tropicana, Las Vegas, NV, USA

Ali Hussain Reshak

Accepted Abstracts: J Material Sci

Abstract :

Ahoneycomb two dimensional lattice of monolayer carbon atoms is a new material called graphene which is discovered recently. Graphene consists of a single atomic layer of sp2 hybridized carbon atoms that result in a hexagonal lattice. Around each carbon atom, three strong σ bonds are established with the other three surrounding carbon atoms. Graphene opened a new era in nanotechnology. The outstanding mechanical, electrical and physical properties of graphene warrants its use in a variety of areas such as hydrogen technology, electronics, sensing and drug delivery, among many others. The zero band gap of the graphene sheets renders the construction of graphene based field effect transistors very difficult. Therefore, several groups have been proposed different methods to open a band gap in graphene. The electronic structure of pristine graphene sheet and three different adsorption sites of H 2 S onto graphene sheet were studied. Calculations show that the adsorption of H 2 S on top site open very small direct energy gap. Comparing the angular momentum decomposition of the atoms projected electronic density of states of pristine graphene sheet with that of H 2 S-pristine graphene for three different sites (bridge, top and hollow), we found significant influence and strong hybridization between H 2 S molecule and graphene sheet. Thus pristine graphene sheet is very good adsorbent materials for H 2 S molecule. In addition, the linear and nonlinear optical susceptibilities of pristine graphene and H 2 S adsorbed at three different sites onto graphene sheet are calculated so as to obtain further insight into the electronic properties. Calculations show that the adsorption of H 2 S on top site cause significant changes in the linear and nonlinear optical susceptibilities. That is attributed to the fact that adsorbing H 2 S onto graphene sheet causes significant changes in the electronic structures, and strong hybridization between H 2 S molecule and graphene sheet, as a result of the strong hybridization, strong covalent bonds were established between C, H, and S. DFT calculations based on all-electron full potential linearized augmented plane wave (FP-LAPW) method, was used. In order to understand the adsorption properties of H 2 S molecule adsorbed onto graphene, all possible adsorption configurations (top, bridge and hollow -sites) were considered.

Biography :

Ali Sarafraz Yazdi has completed his Ph.D. at the age of 30 years from Birmingham University in England. He is the full Professor in analytical chemistry in Ferdowsi University of Mashhad, Iran. He has published more than 60 papers in reputed journals and serving as a reviewer of many reputed journals.