• Title/Summary/Keyword: Spectroelectrochemistry

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Species Selective Spectroelectrochemistry Employing Derivative Absorbance Signals

  • Zhang, Chaojiong;Park, Su-Moon
    • Bulletin of the Korean Chemical Society
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    • v.10 no.3
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    • pp.302-308
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    • 1989
  • Species selective spectroelectrochemistry (SSSE) is described by relating the derivative absorbance (dA/dt) signals with electrochemical currents for conventional transient electrochemical experiments. Expressions relating the currents with the dA/dt signals were obtained. From these expressions, physical constants such as coefficients and molar absorptivities of electrogenerated species can be determined. By obtaining both derivative absorbance and current signals concurrently and comparing them, one can perform the SSSE experiments. The utility of the SSSE in sorting out electrochemical information is demonstrated.

Electrocatalytic Reduction of Dioxygen by Cobaltporphyrin in Aqueous Solutions

  • 전승원;이효경;김송미
    • Bulletin of the Korean Chemical Society
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    • v.19 no.8
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    • pp.825-830
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    • 1998
  • The electrocatalytic reduction of dioxygen by Co(TTFP)(Y)2 {Y=H2O or HO-} is investigated by cyclic voltammetry, spectroelectrochemistry, hydrodynamic voltammetry at a glassy carbon electrode in dioxygen-saturated aqueous solutions. Electrocatalytic reduction of dioxygen by CoⅡ(TTFP)(Y)2 establishes a pathway of 2e- reduction to form hydrogen peroxide, and then the generated hydrogen peroxide is reduced to water by CoⅠ(TTFP)(Y)2 at more negative potential. CoⅡ(TTFP)(Y)2 may bind dioxygen to produce the adduct complex [CoⅡ-O2 or CoⅢ-O2] which exhibits a Soret band at 411 nm and Q band at 531 nm.

Electrochemical Study of Poly(aniline N-alkylsulfonate)s

  • Kim, Eunkyoung;Rhee, Suh Bong
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.631-636
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    • 1995
  • Electrochemical properties of self-dopable poly(aniline N-butylsulfonate)s in various acidic medium were investigated by spectroelectrochemical techniques. Cyclic voltammetric study showed more than two reversible process of one electron transfer, the potential and peak intensity of which were dependent on the acid concentration and dopant ion. Spectroscopic study at different oxidation level indicated that the electrochromic switching of the poly(aniline N-alkylsulfonate)s film involves structural changes from benzenoid ring to quinoid ring. Spectrocyclic voltammetry together with impedance spectra of the PANBUS film in 0.1 M $LiClO_4$ solution of acetonitrile containing 0.46 M of perchloric acid showed two types of highly conductive states at the intermediate oxidation levels, which can be related to the metallic polaron states doped by two different process.

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Electrochromic Property of a Conductive Polymer Film Fabricated with Vapor Phase Polymerization (증기중합으로 제조된 전도성 고분자 박막의 전기 변색 특성)

  • Lee, Ji-Yea;Kim, Yu-Na;Kim, Eun-Kyoung
    • Membrane Journal
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    • v.20 no.1
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    • pp.8-12
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    • 2010
  • Poly(3,4-ethylenedioxythiophene) (PEDOT), which has the highest stability in conducting polymer was employed to electrochromic (EC) film and studied about electrochromic properties according to the film fabrication method. PEDOT films were coated by two different methods, electropolymerization (EP) and vapor phase polymerization (VPP). Both of PEDOT films showed dark blue color at dedoped neutral state. Spectroelectrochemistry, switching ability and stability of the devices were investigated by UV-Vis Spectrophotometer and Cyclic voltammetry. Surface morphologies of the PEDOT VPP film at oxidized and reduced state were obtained by AFM. The average surface roughness of the PEDOT-VPP film was 50 nm and more homogeneous than that of the PEDOT-EP. The EC property from the PEDOT-VPP film was improved compared to that of the PEDOT-EP film, to show a response time of 1.5 sec, transmittancechange of 49%, and coloration efficiency of 402.

Preparation of Conducting Polymer PEDiTT Thin Film Using SAM Method (자기조립법을 이용한 전도성고분자 PEDiTT박막의 제조)

  • 손용근;강규식;심창용;최정식;이두연
    • Polymer(Korea)
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    • v.26 no.5
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    • pp.589-598
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    • 2002
  • thiathlophene (EDiTT) was synthesized. The yield of the synthesis was about 29%. The monomer was identified by using NMR, IR and UV/Vis spectroscopic methods. Poly (3,4-ethylenedithiathiophene) (PEDiTT) was prepared using this monomer and FeCl$_3$. The deep blue green color of the product was changed into brown color by the reduction with $N_2$H$_4$. This was soluble to common organic solvents. Spectroelectrochemistry was used to characterize the PEDiTT. NMP was the best solvent for PEDiTT. PEDiTT/NMP solution was used for making SAM type thin film of the polymer on gold electrode. Electrochemical and IR spectroscopic methods were used to identify the thin film.