• Title/Summary/Keyword: Cyclicvoltammetry

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Electrochemical Properties of Polypyrrole/ Glucose Oxidase Enzyme Electrode (Polypyrrole/Glucose Oxidase 효소전극의 전기화학적 특성)

  • 김현철;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.357-361
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    • 1999
  • GOD electrochemically immobilized in PPy/GOD complex have an effect on redox properties of the complex. In the cyclicvoltammetry, GOD shows the redox reaction at the potential below -0.6Y vs. Ag/AgCI. That leads to new peaks in the cyclicvoltammograms in additional to typical PPy peaks. The pH of electrolyte solution during potential swing decreased to 4.4, and then increased to 10. That suggests the redox of GOD for the cycling. As the concentration of GOD was increased, the anodic wave of the new peaks was strong as much as increased. GOD obstructs the diffusion of electrolyte anion because of its net chain. Insulating property of GOD is cause that it made the faradic impedance of complex large in charge transfer. It suggests that increase of the concentration of GOD be against electrochemical coupling. Therefore, the concentration of GOD and electrochemical coupling should be dealt with each other. The apparent Michaelis-lenten constant ( K\`$_{M}$ ) was determined by 30.7 mmol d $m^{-3}$ fur the PPy/GOD complex. The value is of the same order of magnitude as that for soluble glucose oxidase from Aspergillus Niger.r.

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Electrochemical Corrosion Characteristics of AISI-type 316 L Stainless Steel in Anode-Gas Environment of MCFC (용융탄산염 연료전지의 Anode가스 분위기에서 AISI-type 316L stainless steel의 전기화학적 부식 특성)

  • Lee, Kab-Soo;Lim, Tae-Hoon;Hong, Seong-Ahn;Kim, Hwa-Yong
    • Journal of the Korean Electrochemical Society
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    • v.5 no.2
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    • pp.62-67
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    • 2002
  • The corrosion of the metallic cell components is blown to be one of the major reason f3r the performance degradation and subsequently the life-time limitation of the MCFC. To elucidate the corrosion phenomena, a corrosion study with the AISI-type 316L stainless steel, the most widely used separator material, in 621Li/38K carbonate eutectic melt was carried out. Corrosion phenomena in an MCFC were observed to differ from one location to another due to different environmental condition. The stability of passive film was found to be responsible fur the variations in corrosion phenomena. According to the potentiodynamic analysis, the passive film formed in anode-gas environment was less stable than in cathode-gas environment. The potentiostatic method combined with XRD analysis in addition to the cyclicvoltammetry was conducted to get an insight on variety corrosion reaction of AISI-type 316L stainless steel in a carbonate melt.

Electrochemical Properties and Fabrication of Conjugated System Conducting Oligomer Self-assembled Monolayer (공액구조 전도성 올리고머 자기조립단분자막의 제작 및 전기화학적 특성)

  • Min, Hyun Sik;Lee, Tae Yeon;Oh, Se Young
    • Applied Chemistry for Engineering
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    • v.22 no.5
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    • pp.545-550
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    • 2011
  • We have synthesized a high electrically conductive 4-(2-(4-(acetylthio)phenyl)ethynyl)benzoic acid (APBA) with a conjugated aromatic structure as a bio fix linker, and then fabricated APBA self-assembled monolayer (SAM) with a self-assembly technique. The structure of the prepared APBA SAM was studied and electrochemical properties of APBA SAM immobilized with a ferrocene molecule were investigated. Also, we have examined the molecular orientation and oxidation-reduction redox characteristics of the mixed SAM consisting of APBA and butanethiol (BT) with a X-ray photo electron spectroscopy (XPS) and cyclicvoltammetry, respectively. Electrochemical activity of the mixed SAM was increased with increasing the mixed time. Especially, the maximum redox current was obtained at a mixed time of 36 hrs.

Effect of Carbon Felt Oxidation Methods on the Electrode Performance of Vanadium Redox Flow Battery (탄소펠트의 산화처리 방법이 바나듐 레독스 흐름 전지의 전극 성능에 미치는 영향)

  • Ha, Dal-Yong;Kim, Sang-Kyung;Jung, Doo-Hwan;Lim, Seong-Yop;Peck, Dong-Hyun;Lee, Byung-Rok;Lee, Kwan-Young
    • Journal of the Korean Electrochemical Society
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    • v.12 no.3
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    • pp.263-270
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    • 2009
  • Carbon felt surface was modified by heat or acid treatment in order to use for the electrode of a redox-flow battery. Polymers on the surface of carbon felt was removed and oxygen-containing functional group was attached after the thermal treatment of carbon felt. Thermal treatment was better for the stability of the carbon structure than the acid treatment. Oxygen-containing functional group on the thermally treated carbon felt at 500$^{\circ}C$ was confirmed by XPS and elementary analysis. BET surface area was increased from nearly zero to 96 $m^2/g$. Thermally treated carbon felt at 500$^{\circ}C$ showed lower activation polarization than the thermally treated carbon felt at 400$^{\circ}C$ and the acid-treated carbon felt in the cyclicvoltammetry and polarization experiments. The thermally treated carbon felts at 400$^{\circ}C$ and 500$^{\circ}C$ and the acid-treated carbon felt was applied for the electrode to prepare vanadium redox flow battery. Voltage efficiencies of charge/discharge were 86.6%, 89.6%, and 96.9% for the thermally treated carbon felts at 400$^{\circ}C$ and 500$^{\circ}C$ and the acid-treated carbon felt, respectively.