Primary Principle Of Hydrogenation And Graphite Fluoride Ene Material Research

Graphene is a rapidly developmental star in the field of materials science and condensed matterphysics, this kind of two-dimensional material shows a serials of special characters, such as specialgrid and special electronic properties. Graphene consist of carbon which is closely stacked. Grapheneis elementary unit of building other carbonaceous materials, such as fullerenes, carbon nano-tubes,three dimensional graphite and so on. Graphene has a large amount of potential implements in manyfields, such as hydrogen storage, sensors, composite materials, computer etc. With the rapiddevelopment of the related theory and numerical algorithm, the first principle calculation which isbased on density functional theory has a very wide range of applications in many fields includingcondensed matter physics, material sciences and so on. This paper shows the study of the firstprinciple calculation on different sizes of grapheme supercell.The first part mainly introduces that the graphene is discovered by A. K. Geim who used themethod of tearing adhesive tape in2004, and the characters of graphene such as high conductivity,high transfer rate, high mechanical strength, easy to modify and abundant production and so on, andgraphene has novel characters such as integer quantum hall effect and fractional quantum hall effectetc. It also shows the common method of producing graphene, such as micro mechanical separation,chemical vapor deposition, oxidation graphite reduction method, etc., and introducing the recentresearching progress of graphene at home and abroad, and the purpose and meaning of researchinggraphene.The second part mainly introduces the specific contents of the first principle calculations, suchas the expression forms of non relativistic Hamiltonian in multi-particle system and at thecorresponding effective potential equation; It introduce the non relativistic approximation whichignoring the effect of non relativity, and introducing the adiabatic approximation which consideringthe movement of nucleus and electrons independently, and introducing the single electronicapproximate which make the Coulomb interaction of electrons separate, and the concept of densityfunctional theory, Hohenberg-Kohn theorem and Kohn-Sham equation, the two methods of dealingwith Exchange association, such as the local density approximation and generalized gradientapproximation.The third part mainly introduces that using the method of LDA and GGA,we study thestructure and character of the pure graphene consisting of two carbon atoms (single cell), eight carbonatoms (super cell),32carbon atoms (super cell), the results indicate that the length between C and Cis1.41,there is a unique Dirac point in particular point K from its figures of DOS and energy band,graphene is semiconductor with zero band gap. We also study the structure and character ofhydrogenated graphene when graphene adsorb H based on the ratio of1:1,2;1,4:1,8:1,16:1between C and H. the results demonstrate that the length between C and C is longer than pure graphene, thelength between C and H is about1.1, the total magnetic moment is zero when graphene adsorb thetwo H atoms from the two sides of graphene, the energy gap is bigger when the ratio between C andH is bigger.The fourth part mainly introduces that using the method of LDA,we study the structure andcharacters of fluorination graphene when graphene adsorb F based on the ratio of1:1,2:1.4:1,8:1,16:1between C and F. the results indicate that the length between C and C is longer than pure graphene,the length between C and F is about1.4, the total magnetic moment is zero when graphene adsorbthe two F atoms from the two sides of graphene, the energy gap is bigger first, then smaller, lastbigger when the ratio between C and H is bigger.