Electronic And Catalytic Properties Of Core/Shell Doped Graphene Material

Graphene exhibits excellent physical and chemical properties,such as Quantum hall effect,Quantum suiting effect,excellent electrical conductivity and malleability,which make more classes graphene two-dimensional nanomaterials research scholars at home and abroad widely attention to study.However,Two fundamental obstacles towards the extensive application of pristine graphene are nonmagnetic and semimetal with zero energy band gap.An abundant of chemical and physical means must be used to cross two fundamental obstacles of graphene.Moreover,Several defects are find to exist in graphene,such as Frenkel defect,Schottky defect,impurity defect,line defect,point defect,planar defect and so on.The abundant of defects make it possible to use the means of doping to modified graphene.In order to expand the application of graphene materials,researchers found,we can precisely control core-shell structure doping in graphene,which can be formed a modification graphene films.The modification graphene films can exhibits excellent optical,electrical,magnetic,and catalytic properties.We explore the electronic,catalytic and magnetic property of graphene or the heterojunction of graphene with different core/shell based on DFT method using the first principle of calculation.In this paper,the main work and innovations are as follows:?1?Utilizing first-principle calculations,the structural,electronic and magnetic properties of monolayer graphene embedded with Fe_n/X_m?X=C,N,O,Cl,S and F?core/shell clusters are investigated,where n=1,2,3 and m=4,6 respectively.We find that the graphene e?Bedding with the Fe_n/X_m core/shell clusters are magnetic except the Fe/S₄,Fe₂/C₄ and Fe₃/Cl₆ core/shell clusters.The graphene embedded with the Fe3/F6 core/shell cluster has the largest magnetic moment in these systems.Magnetism for Fe_n/X_m core/shell clusters embedded in monolayer graphene can be ascribed to the ferromagnetic coupling between the Fe atoms.Our calculations demonstrate that Fe atoms are successfully isolated at various C,N,O,Cl,S and F shells in graphene to preserve the high-spin state.On the other hand,the high-spin state is also effectively controlled by the amount of Fe atoms.The electron spin can be stored in magnetic thin film,lithographically prepared quantum dots,and electromagnetic traps.The Fen/Xm core/shell clusters embedded in graphene can be considered to have potential applications in nanoelectronics,spintronics and magnetic storage devices.?2?Fe/N₂-G system with C_2h symmetry facilitates the O₂ adsorption.The strong interaction between the Fe atom and O₂ in Fe/N₂-G system can be contributed from the high energy of Fe'sd_z2 orbit.The CO oxidation reaction on Fe/N₂-G system has a small energy barrier?0.43 eV?by the Langmuir–Hinshelwood?LH?mechanism?CO+O₂?OOCO?CO₂+Oads?,which would be useful in evaluating the reactivity of Fe catalyst and serving as a good candidate for effient non-noble metal catalyst.The results provide valuable guidance on selecting catalysts of low cost and superior activity to fabricate graphene-based materials.?3?Developing simple methods to manipulate and detect the materials'spin orientation is among the key issues for spintronics applications.The advantage of using electric fild to control spin orientation is that the fild can be easily applied locally.The magnetic moment and spin polarization of the tri-P atoms in P-doped graphene?G?/boron nitride?BN?and BN/P-doped G/BN heterostructures with effective control via an external electric fild are studied.The spin properties in the mono-,di-P atoms doped G/BN,mono-vacancy G/BN,tri-N and tri-O atoms doped mono-vacancy G/BN systems are little dependent on the external electronic fild.The electric fild can induce a transformation from bipolar magnetic semiconductor?BMS?character to spin gapless semiconductor?SGS?character for tri-P-G/BN system.The novel property of electrical controlling spin polarization presents at a high Curie temperature.In summary,these results provide perspectives for a control of graphene with core/shell doping for versatile graphene based materials.