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Scanning tunneling microscopy (STM) Atomic force microscopy (AFM)

B Spectroelectrochemistry (ch. 17). Scanning tunneling microscopy (STM) Atomic force microscopy (AFM) Scanning electrochemical microscopy (SECM) UV & visible spectroscopy Transmission experiments Specular reflectance & ellipsometry Internal reflection spectroelectrochemistry

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Scanning tunneling microscopy (STM) Atomic force microscopy (AFM)

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  1. B Spectroelectrochemistry (ch. 17) Scanning tunneling microscopy (STM) Atomic force microscopy (AFM) Scanning electrochemical microscopy (SECM) UV & visible spectroscopy Transmission experiments Specular reflectance & ellipsometry Internal reflection spectroelectrochemistry Second harmonic spectroscopy Vibrational spectroscopy: IR spectroscopy, Raman spectroscopy Electron & ion spectroscopy XPS, AES, LEED, HREELS, mass spectroscopy Magnetic resonance methods: ESR, NMR Quartz crystal microbalance X-ray methods: XAS, XRD

  2. Vibration spectroscopy Infrared spectroscopy Infrared spectroelectrochemistry (IR-SEC)

  3. Cell for IR-SEC

  4. EMIRS (electrochemically modulated infrared reflectance spectrosocpy) Potential is modulated between one where the species of interest is absent & one where it is electrochemically generated

  5. SNIFTIRS (subtractively normalized interfacial Fourier transform IRS) or PDIRS (potential difference IRS) or SPAIRS (single potential alteration) Spectra obtained separately at two potentials → subtraction

  6. IRRAS (IR reflection absorption spectroscopy) IR absorption at fixed potential

  7. SEIRA (surface enhanced IR absorption) IR to study adsorbed species (reactants, intermediates, products) → orientation & potential dependence of the adsorbed species SNIFTIRS

  8. IR incidence sample ZnSe or KRS-5 crystal In-situ FT-IR spectroscopy • Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFT) • Attenuated Total Reflectance Spectroscopy (ATR) *Transmission measurement *Reflection-Aborption infrared Spectroscopy (RAS) *Photoacoustic Spectroscopy (PAS) *Surface Electromagnetic Wave spectroscopy (SEW)

  9. In-situ FT-IR In situ FT- IR cell

  10. In situFT-IR CO/Pt

  11. Raman spectroscopy

  12. Raman spectroscopy: molecular vibrational information complementing IR spec. Raman in electrochemical system: signal enhancement - Resonance Raman spectroscopy (RRS) - Surface enhanced Raman spec. (SERS): molecules adsorbed on certain surfaces (Ag or Au)

  13. RRS of TCNQ & electrochemically generated TCNQ-

  14. Transients in Raman intensity

  15. SERS for Os compound on Ag electrode as ftn of potential

  16. SER spectra for benzene on Pd

  17. In-situ Raman Spectroscopy

  18. Fresh anode In-situ Raman microscopy (탄소재 음극과 LiCoO2양극재 분석) 25oC 60oC LiCoO2 graphite acetylene black Brodd (2003)

  19. Electron and ion spectrometry Ultra high vacuum (UHV) Excitation Detection X-ray photoelectron spectroscopy (XPS) Photons(X-ray) Electrons UV photoelectron spectroscopy (UPS) Photons (UV) Electrons Auger electron spectroscopy (AES) Electrons Electrons Low-energy electron diffraction (LEED) Electrons Electrons High resolution e- E loss spec. (HREELS) Electrons Electrons Rutherford backscattering (RBS) H+ or He+ H+ or He+ Secondary ion mass spec. (SIMS) Ions Ions Laser desorption mass spec. (LDMS) Photons Ions

  20. Detection limits, sampling depth, spot size (spatial resolution)

  21. UHV-electrochemistry

  22. X-ray photoelectron spectroscopy (XPS, or ESCA)

  23. Schematic diagram of XPS

  24. XPS for Pt 4f levels:

  25. XPS for gassy carbon electrodes

  26. XPS for copper electrodeposition (a) Bulk Cu (b) Cu UPD

  27. Electrochemical X-ray Photoelectron Spectroscopy Univ. of Illinois

  28. Electrochemical XPS UHV-XPS Glove Box Ex-situ Analysis without Contamination

  29. Auger electron spectroscopy

  30. Ni oxide on Au

  31. AES Depth profiles for GaAs

  32. AES depth profiles for MgPc

  33. Electrochemical Auger Electron Spectroscopy

  34. Low-energy electron diffraction

  35. High resolution electron energy loss spectroscopy • SCN- on Ag(111) • -0.3 V • +0.14 V

  36. Mass spectrometry Differential electrochemical mass spectrometry (DEMS)

  37. DEMS: fuel cell catalysts for methanol(solid) & formic acid(dotted) oxidation

  38. Magnetic resonance methods Electron spin resonance & NMR

  39. Electrochemical ESR

  40. Quartz crystal microbalance

  41. QCM: PVF on Au

  42. X-ray methods Synchrotron X-ray absorption spectroscopy Absorption edge (energy that is just needed to eject a particular core electron, e.g., 1s e- (K edge), 2p3/2 e- (L3 edge) Fe & Fe oxides K-edge: 7.112 keV Within 10-40 eV: X-ray absorption near-edge structure (XANES) (or near-edge absorption fine structure (NEXAFS)) → oxidation state & ligand envirionment About 50 keV: extended X-ray absorption Fine structure (EXAFS) → distance & arrangement of atoms

  43. X-ray diffraction techniques

  44. In-situ XRD In-situ XRD patterns of LixFeSnO4 during initial lithium intercalation and deintercalation.

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