Uhlíkové nanostruktury-materiály ypro budoucnost?

Transcription

1 Uhlíkové nanostruktury-materiály ypro budoucnost? Martin Kalbáč IFW Dresden Ústav fyzikální chemie J. Heyrovského, Praha Massachusetts Institute of Technology (MIT), Cambridge,USA

2 Forms of carbon Nanotubes Fullerenes Diamond Graphite Graphene

3 Content: 1) Grafen 2) Fullereny 3) Nanotuby 4) Peapody 5) DWCNTs 6) Spektroelektrochemie

4

5 Graphite Forms of carbon

6 Graphene Forms of carbon

7 Graphene applications Ultrathin conductive films Graphene Used To Create World's Smallest ttransistor Liquid Crystal Device with electrodes made of graphene with different voltages applied. The overall width of the insert image is 30 microns. (Image: Mesoscopic Physics Group, University of Manchester) Dr Ponomarenko, who carried out this work, shows his research sample: graphene quantum dots on a chip.

8 Graphene applications Single molecule gas detection Ultracapacitors Spin transport Schematic of the resonator. The graphene is in contact with a gold electrode that can be used to electrostatically actuate the resonator. A red laser is used to detect the motion of the resonator by laser interferometry.

9 Forms of carbon Graphene 0.70 per μm per mm 2

10 Graphene Forms of carbon

11 Graphene Forms of carbon

12 Chemical vapor deposition (CVD) Cu or Ni Quartz substrate boat Quartz tube Electric furnace Ar H2/CH4 or Ar/H 2 Ethanol tank Hot bath

13 Chemical vapor deposition (CVD)

14 Transfer of graphene

15 Transfer of graphene

16 Chemical vapor deposition (CVD)

17 Expo '67 American Pavillion by R. Buckminster Fuller, on Ile Sainte-Hélène, Montreal

18 C 60 acc. to IUPAC: Hentriacontacyclo[ ,14.0 3,12.0 4,59.0 5,10.0 6,58.0 7,55.0 8,53.0 9, , , , , , , , , , , , , , , , , , , , ,46 ]hexaconta- 1,3,5(10),6,8,11,13(18),14,16,19,21,23,25,27,29(45), 11 13(18) (45) 30,32(44),33,35(43),36,38(54),39(51),40(48),41,46,49, 52,55,57, 59-triaconten Kroto, Allaf, Balm, Chem. Rev. 91, 1991, 1213

19 Fullerene gallery C 60 C 70 C 76 C 78 C 82 La@C 84 Sc 3 N@C 84 Endohedral Fullerene M@C 84

20 Carbon nanotubes

21 Rolling of SWCNT -zag zigarm-chair

22 Carbon nanotubes (CNT) SWCNT MWCNT DW CNT

23 SWCNT Bundles

24 SWCNT Bundles

25 Single wall carbon nanotubes (SWCNT) Size: Nanostructures with dimensions of ~1 nm diameter (~10 atoms around the cylinder) Physics: 1D density of electronic states. Single molecule Raman spectroscopy, luminescence, and transport properties. Electronic Properties: Can be either metallic or semiconducting depending on diameter and orientation of the hexagons Mechanical Properties: Very high strength. Good properties on both compression and extension.

26 Carbon nanotubes (CNT) mechanical properties Fiber material Specific E Strength Strain at break density (TPa) (GPa) (%) CNT HS Steel <10 CF-PAN Kevlar

27 Carbon nanotubes (CNT) mechanical properties

28 Single nanotube transistor Distinctive metallic and semiconducting transport properties IBM Ballistic transport Extremely high current carrying capacity

29 Chemical vapor deposition (CVD) Quartz boat Quartz tube Electric furnace Ar or Ar/H 2 Ethanol tank Hot bath

30 Quality vs. price

31 Commercial 90% carbon purity 500 $ /g Purity of carbon nanotubes

32 SWCNT from graphene A a 1 6 a 1 a 2 5a 2 C h B Chiral vector: C h = na 6a 1 + ma 5a 2 a 1, a 2. Unit vectors of 2D-hexagonal lattice (6,5)

33 SWCNT from graphene Armchair nt (n=m) metal Zig-zag nt (n-m) = 3i metal (n-m) 3i semicond. Chiral nt (n-m) =3i metal (n-m) 3i semicond.

34 Density of states (DOS) in SWCNT Van Hove singularities (5,5) Armchair tubes (5,5) 5) Zig-zag tubes (5,0) om/ev) (states/c-at DOS (10,10) (10,0) DOS (states/c-at tom/ev) (20,20) (20,0) Energy, ev Energy, ev

35 ΔE of singularities vs. diameter of SWCNT ( Kataura graph ) 2χ0 ac C ΔE = SWCNT d d nm (10,10) Ene ergy, ev Energy Sepa aration (ev) v 2 m c m 2 v s3 c 3 s v m1 c 1 m Energy, ev DOS v s2 c s 2 v s1 c s 1 (11,9) Nanotube diameter (nm) -1.0 (n, m) to (40,40) -1.5 DOS

36 Vis/NIR spectrum of SWCNT/ITO 0.5 hv Absorbance v s1 c s 1 v s2 c s 2 v m1 1 c m 0.1 SWCNT ITO Energy, ev

37 SWCNT Bundles

38 Sorting SWCNT

39 What is the Raman spectroscopy py about C. V. Raman

40 Resonance enhanced Raman spectroscopy Approximately 1 in 10 7 photons is inelastically scattered The signal is usally very weak 1) Use of lasers - intensive light 2) Resonance enhancement

41 Resonance enhanced Raman spectroscopy Virtual state E 1 V 0 Optical transition? E 0 V 1 E 0 V 0 Resonance enhanced spectra

42 Resonance Raman spectroscopy of SWCNT I = c ( E E iγ )( E + E E iγ ) L ii L ph ii 2 E L - laser photon energy E ii - optical transition energy E ph - phonon energy γ - damping constant Typical values for RBM E ph 0.02 ev γ 0.05 ev

43 Raman spectrum of SWCNT 1.83 ev 2.41 ev TG Raman int tensity, a. u. x 5 x 25 RBM D G Raman shift, cm Diameter = 234/ω RBM

44 Growth of CNT

45 Raman spectra of SWCNT, hv exc = 1.83 ev x 1.5 y, a.u. man intensity Bundle Ra Raman shift, cm

46 Creation of defects in SWCNT RF Ar plasma Individual SWCNT Mask Substrate

47 Defective SWCNT x 30 Raman inte ensity, a.u. x10 3 D mode Pristine part Defective part Raman shift, cm Diameter = 234/ω RBM

48 Formation of fullerene peapod (C C 60 (g) FULLERENE PEAPOD Nanotube, optimum 1.36 nm

49 Dy 3 N@C Dy 3 N@C Dysprosium (at approx. 154 ev) from EELS spectra J.Cech, M. Kalbáč, S.A. Curran, D. Zhang, U. Dettlaff-Weglikowska, L. Dunsch, S. Yang and S. Roth: Physica E: Low-dimensional Systems and Nanostructures, in press (2006) Distance (nm)

50 Raman spectra of Dy 3 N@C hv exc = 1.91 ev y, a. u. intensity Raman Dy 3 N@C SWCNT Dy 3 N@C 80 x Raman shift, cm

51 Double walled nanotubes RT C 800 o C 1200 o C DWCNT 1000 o C 1200 o C S. Bandow et al., Chem. Phys. Lett. 337 (2001) 48

52 Raman spectra of dry DWCNT, hv exc = 1.83 ev Raman intens sity, a. u. OUTER TUBES INNER TUBES Raman shift, cm

53 Double walled nanotubes from different peapod sources (The spectra are excited by 1.83 ev) C 60 -DWCNT C 70 -DWCNT C 78 -DWCNT Raman intensity, a. u. Raman intensity, a. u. Raman intensity, a. u Raman shift, cm Raman 300 shift, cm Raman shift, cm C 84 -DWCNT La@C 82 -DWCNT Dy 3 N@C 80 -DWCNT Raman in ntensity, a. u. Raman in ntensity, a. u. Raman in ntensity, a. u Raman shift, cm Raman shift, cm Raman shift, cm

54 In-situ spectroelectrochemistry The change of potential The change of electronic state The change of spectra Methods EPR UV-Vis-NIR Vis Raman FTIR Materials conducting polymers monomers, oligomers fullerenes CNT peapods

55 Cat2 An1 OCP Cat1 An2 In-situ electrochemical doping of SWCNT anodic/cathodic= extraction/insertion of e - Fermi level Fermi level Fermi level Fermi level Fermi level Fermi level Electrode

56 Vis-NIR spectra on ITO electrode of SWCNT (0.22 M LiClO 4 + acetonitrile) RE 0.50 Energy, ev CE WE hv bsorbance (A) DOS A 0.30 Energy, ev sample ITO Energy, ev E = 0.0V 0.2V 0.4V 0.6V 0.8V 1.0V 1.2V 1.4V 1.6V DOS

57 Raman spectra of SWCNT, hv exc = 2.54 ev (0.2 M LiClO 4 + acetonitrile) I = c ( E E iγ )( E + E E iγ ) L ii L ph ii V Spectroelectrochemical cell x40 RE (Ag/AgCl) Pyrex window N -outlet 2 N 2 -inlet CE (Pt) Electrolyte solution V an intens ity, a. u. Ram y, a. u. Raman intensity (vs. Fc/Fc + ) WE Raman shift, cm -1

58 Raman spectra of DWCNT, hv exc = 1.83 ev (0.2 M LiClO 4 + acetonitrile) 1.5 V 1.2 V 0.9 V Raman inten nsity, a. u. 0.6 V 0.3 V 0V -0.3 V -0.6 V -0.9 V -1.2 V -1.5 V Raman shift, cm M. Kalbáč, L. Kavan, M. Zukalová and L. Dunsch: Adv. Funct. Mater., 15, , (2005).

59 THANK YOU!!! Financial support: GACR-DFG GA AV MSMT-USA Kontakt: 1) M. Kalbac, L. Kavan, L. Dunsch and M.S. Dresselhaus. Nanoletters, 8, (2008). 2) M. Kalbac, L. Kavan, M. Zukalová and L. Dunsch. Chemistry - A Eur. J., 14, (2008). 3) M. Kalbac, L. Kavan, L. Dunsch. J. Phys. Chem C. 112(43), (2008). 4) M. Kalbac, H. Farhat, L. Kavan, J. Kong, M.S. Dresselhaus. Nanoletters, 8 (10), (2008). 5) M. Kalbac, L. Kavan, L. Dunsch. J. Phys. Chem C. 113(4), (2009). 6) M. Kalbac, L. Kavan, H. Farhat, J. Kong, M.S. Dresselhaus. J. Phys. Chem C. 113(5), (2009). 7) M. Kalbac, L. Kavan, L. Dunsch: J. Am. Chem. Soc. 131(12) , (2009). 8) M. Kalbac, H. Farhat, L. Kavan, J. Kong, K. Sasaki, R.Saito and M. S. Dresselhaus. ACS Nano, 3 (8), (2009). 9) M. Kalbac, A. A. Green, M. C. Hersam, and L. Kavan. ACS Nano, 4 (1), (2010). 10) M. Kalbac, V. Zólyomi, Á. Rusznyák, J. Koltai, J. Kürti and L. Kavan. J. Phys. Chem C. 114, (2010).