1. Chemical Modification of Graphene Tobe lab M1 Kosuke HADA 1

2. Introduction Representative previous work about chemical modification of graphene My work Summary 2 Outline

3. Graphene 3 Graphite Graphene

4. 4 Graphene was isolated by using adhesive tape. Novoselov and Geim won the Nobel Prize in 2010. Novoselov, K. S. et al. Science 2004, 306, 666-669.

5. Graphene 5 Zboril, R. et al. Chem. Rev. 2012, 112, 6156−6214. Properties of Graphene ・ Strength ・ Zero band gap ・ Ultrahigh carrier mobility New Material Touch screens Sensor Solar cell

6. 6 Chemical Modification ( 化学修飾 ) of Graphene sp 2 carbon : conductive sp 3 carbon : non-conductive Changing of sp 2 Carbons to sp 3 Carbons by Addition of Organic Molecules Graphene Controlling conductivity of graphene Functionalizing property of graphene

7. Representative Previous Work on Chemical Modification of Graphene 7 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

8. Representative Previous Work on Chemical Modification of Graphene 8 Nitrophenyl Radical Epitaxial Graphene (EG) Sic SiC Sic Graphene 1100 ℃ Method of Chemical Modification

9. Raman Spectrum Mechanism 9

10. Raman Spectrum vibration of lattice of graphene 10 vibration of defects Functionalized by Nitrophenyl Epitaxial Graphene One or Two Layered Graphene

11. Scanning Tunneling Microscopy (STM) Mechanism 11 Tunneling current

12. Fast Fourier Transform (FFT) 12 higher-order filtered lower-order filtered Mechanism

13. 13 STM Nitrophenyl Functionalized Epitaxial Graphene removing graphene lattice higher-order filtered Epitaxial Graphene

14. STM 14 superimpose ( 重ね合わせ ) superimpose ( 重ね合わせ ) Epitaxial Graphene Nitrophenyl Functionalized Epitaxial Graphene

15. STM 15 superimpose ( 重ね合わせ ) Moire pattern ( モアレ模様 ) Sic Graphene Epitaxial Graphene

16. STM 16 superimpose ( 重ね合わせ ) Nitrophenyl Functionalized Epitaxial Graphene

17. Resistance 17 0.4 kΩ at r.t. 3.2 kΩ at r.t. Epitaxial Graphene Nitrophenyl Functionalized Epitaxial Graphene

18. Raman Spector STM Resistance 18 Summary of the Work ・ Chemical modification change the conductivity of graphene ・ Reaction positions and rate weren’t controlled My purpose is to control reaction positions and rate

19. = molecules = substrate = photoresist = substrate light Top-down approach (photolithography) Bottom-up approach (molecular self-assembly) Self-assembly About 100 nm scale 1~10 nm scale 19 Construction of Nano Structure on Surfaces

20. STM Image of DBA on Graphite Honeycomb Structure of Dehydrobenzo[12]annulene (DBA) at the Liquid/Graphite Interface = 20 DBA Self-Assembly at the Liquid/Solid Interface

21. Characters of DBA DBA = You can change the size of DBA and holes 21

22. Purpose of My Work Chemical stability of diazirine Precursor of carbene Photo-reaction under long wavelength Diazirine Carbene High reactivity Adding to graphene Carbene 22

23. Purpose of My Work = 23 Diazirine Graphene Self-Assembly

24. Graphene Purpose of My Work hv 24

25. 25 Purpose of My Work Graphene and DBA 1 before chemical modification

26. Purpose of My Work 26 Graphene after chemical modification

27. Purpose of My Work 27 14 carbons12 carbons10 carbons Graphene and DBA before chemical modification

28. Purpose of My Work 28 Graphene after chemical modification 28 units36 units46 units 14 carbons12 carbons10 carbons

29. 29 Purpose of My Work Protection from Light

30. STM Image of DBA at the 1,2,4- trichlorobenzene/Graphite Interface 30 2.9 × 10 -6 mol/L STM Image of DBA 1 on Graphite Solvent 1,2,4-trichlorobenzene

31. STM Image of DBA at the 1,2,4- trichlorobenzene/Graphene Interface 2.9 × 10 -6 mol/L Solvent 1,2,4-trichlorobenzene STM Image of DBA 1 on Graphene 31

32. UV Spector after Photo Irradiation 32 photo irradiation of 350~400 nm stable under photo irradiationphoto irradiation generated carbene

33. 33 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.