Interaction Of Phenol Derivatives With Graphene Flakes:A DFT Study

Graphene is the name given to a two-dimensional sheet of sp2-hybridized carbon. Its extended honeycomb network is the basic building block of other important allotropes; it can be stacked to form 3D graphite, rolled to form 1D nanotubes, and wrapped to form 0D fullerenes. Long-range ?-conjugation in graphene yields extraordinary thermal, mechanical, and electrical properties, which have long been the interest of many theoretical studies and more recently became an exciting area for experimentalists. One specific branch of graphene research deals with graphene oxide(GO). This can be considered as a precursor for graphene synthesis by either chemical or thermal reduction processes. GO consists of a single-layer of graphite oxide and is usually produced by the chemical treatment of graphite through oxidation, with subsequent dispersion and exfoliation in water or suitable organic solvents. With respect to its structure, These assume the presence of various oxygen containing functional groups in the GO,This is primarily due to the uncertainty pertaining to both the nature and distribution of the oxygen-containing functional groups,currently the precise atomic structure of GO is still uncertain, Especially, the routes for the modification of GO in chemical way are numberous and worthy to be investigated. In this paper, electronic structures of finite sizes graphene and graphene oxide have been simulated and computed based on the first principles of density functional theory(DFT), which could provide theoretical guidance for their applications in Nano-electronic devices, energy storage and novel sensors.Chapter one: Introduction. This chapter details the existence, application and research methods of graphene; discusses the emergence and development of graphene; describes the mechanical, electrical, thermal properties of grapheme materials. Meanwhile, It also describes the composition structure, material properties and applications field of graphene oxide.Chapter two: Theories and methods of computational chemistry, This chapter discusses the generation and future direction of quantum chemistry, and evolution of the Schr?dinger equation,describes the origin, development and application of density functional theory,especially in the study of carbon materials.Chapter three: Structural properties of graphene by DFT study. In this chapter we have explored the limits of quantum size geometry of graphene nano-sheets, with the increasing number of carbon atoms in graphene the limited size of the increase in the electron energy band gap is gradually narrowing, charge density distribution gradually concentrated at the edge of nanosheets, and exhibit semiconductor properties and metal properties of graphene materials.Chapter four: Graphene, graphene oxide nanosheets with phenol derivatives interactions. In this chapter, we focus on the limited size of the graphene and graphene oxide nanostructure as a base, and six kinds of phenol molecules of different ligand structures to each other effect relationship. The study found that generate ?-? conjugate between graphene nanosheets with phenol molecule interaction, and between the graphene oxide nanosheets with phenol derived molecules are affected by hydrogen bonding interactions. In addition, by comparing the binding energy of discovery, graphene oxide adsorption of phenol molecules can be strong in graphene.Chapter five: Different functional groups-modified graphene oxide with phenol molecules interactions. In this chapter, we study three functional groups as carboxyl, hydroxyl and epoxy groups are modified on the graphene oxide nanosheets, it interacts with molecules of different ligands of phenol. The study found that different functional groups modified functionalized graphene sheets than the energy gap of graphene sheets is slightly smaller than the graphene oxide sheets of a large energy gap. Hydroxyl, epoxy-modified graphene oxide and phenol derivatives molecular interactions, molecules of different ligand binding energy accompanied by a corresponding change in ligand binding energy with the size of meta> ortho> para.