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Chemical Modification of Graphene. T obe lab M1 Kosuke HADA. Outline. Introduction Representative previous work about chemical modification of graphene My work Summary. Graphene. Graphite. Graphene. Graphene. Graphene was isolated by using adhesive tape.
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Chemical Modification of Graphene Tobe lab M1 Kosuke HADA
Outline • Introduction • Representative previous work about chemical modification of graphene • My work • Summary
Graphene Graphite Graphene
Graphene Graphene was isolated by using adhesive tape. Novoselov and Geim won the Nobel Prizein 2010. Graphene Novoselov, K. S. et al. Science2004, 306, 666-669.
Graphene • Properties of Graphene • ・Strength • ・Zero bandgap • ・Ultrahigh carrier mobility Zboril, R. et al. Chem. Rev. 2012, 112, 6156−6214. Touch screens Sensor New Material Solar cell
Chemical Modification (化学修飾) of Graphene Changing of sp2 Carbons to sp3 Carbons by Addition of Organic Molecules • sp2 carbon : conductive • sp3 carbon : non-conductive Graphene • Controllingconductivity of graphene • Functionalizingproperty of graphene
Representative Previous Work onChemical Modification of Graphene Covalent chemistry for graphene electronics Niyogi, S.; Bekyarova, E.; Hong, J.; Khizroev, S.; Berger, C.; Heer, W.; Haddon, R. C. J. Phys. Chem. Lett. 2011, 2, 2487–2498. Nitrophenyl Radical
Representative Previous Work onChemical Modification of Graphene Epitaxial Graphene (EG) 1100℃ Method of Chemical Modification Sic Nitrophenyl Radical Graphene Sic SiC
Raman Spectrum Mechanism
Raman Spectrum Functionalized by Nitrophenyl Epitaxial Graphene One or Two Layered Graphene vibration of lattice of graphene vibration of defects
Tunneling current Scanning Tunneling Microscopy (STM) Mechanism 11
Fast Fourier Transform(FFT) Mechanism lower-order filtered higher-order filtered 12
STM Epitaxial Graphene removing graphene lattice higher-order filtered Nitrophenyl Functionalized Epitaxial Graphene
STM Epitaxial Graphene superimpose (重ね合わせ) Nitrophenyl Functionalized Epitaxial Graphene superimpose (重ね合わせ)
STM Epitaxial Graphene superimpose (重ね合わせ) Graphene Sic Moire pattern (モアレ模様)
STM Nitrophenyl Functionalized Epitaxial Graphene superimpose (重ね合わせ)
Resistance Epitaxial Graphene Nitrophenyl Functionalized Epitaxial Graphene 0.4kΩ at r.t. 3.2kΩ at r.t.
Summary of the Work • Raman Spector • STM • Resistance ・Chemical modification change the conductivity of graphene ・Reaction positions and rate weren’t controlled My purpose is to control reaction positions and rate
Construction of Nano Structure on Surfaces Top-down approach (photolithography) Bottom-up approach (molecular self-assembly) light = molecules = photoresist Self-assembly = substrate = substrate About 100 nm scale 1~10 nm scale
Honeycomb Structureof Dehydrobenzo[12]annulene (DBA) at the Liquid/Graphite Interface DBA = STM Imageof DBA on Graphite Self-Assembly at the Liquid/Solid Interface
Characters of DBA = DBA You can change the size of DBA and holes
Purpose of MyWork Carbene Diazirine Diazirine • Chemical stability of diazirine • Precursor of carbene • Photo-reaction under long wavelength Carbene • High reactivity • Adding to graphene
Purpose of MyWork = Diazirine Self-Assembly Graphene
Purpose of MyWork hv Graphene
Purpose of MyWork Graphene and DBA 1 before chemical modification
Purpose of MyWork Graphene afterchemical modification
Purpose of MyWork 14 carbons 12 carbons 10 carbons Graphene and DBA before chemical modification
Purpose of MyWork 14 carbons 12 carbons 10 carbons 28units 36units 46 units Graphene afterchemical modification
Purpose of My Work Protection from Light
STM Image of DBA at the 1,2,4-trichlorobenzene/GraphiteInterface Solvent 1,2,4-trichlorobenzene STM Imageof DBA 1 on Graphite 2.9 × 10-6 mol/L
STM Image of DBA at the 1,2,4-trichlorobenzene/GrapheneInterface Solvent 1,2,4-trichlorobenzene STM Imageof DBA 1 on Graphene 2.9 × 10-6 mol/L
UVSpector after Photo Irradiation photo irradiation of 350~400 nm stable under photo irradiation photo irradiation generated carbene photo irradiation generated carbene
Summary • Chemical modification changes the properties of graphene. • I designed DBA 1 and synthesized it. • DBA 1 formed honeycomb structures at solvent/graphite and solvent/graphene interfaces. • DBA 1 generates carbene by photo irradiation of about 350 nm.