• 제목/요약/키워드: Electrochemically active specific area

검색결과 5건 처리시간 0.02초

Regulation of Electrochemical Oxidation of Glucose by lonic Strength-Controlled Virtual Area of Nanoporous Platinum Electrode

  • Kim, Jong-Won;Park, Se-Jin
    • 전기화학회지
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    • 제10권3호
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    • pp.203-206
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    • 2007
  • Electrochemical reaction of glucose was regulated by the electrochemically active area of nanoporous platinum, which is controlled by ionic strength. The profile of the oxidation current of glucose vs. ionic strength was identical with that of the electrochemically active area. This result confirms that the nanopores are virtually opened for the electrochemical reaction of glucose when the ionic strength climbs over a specific concentration and implies that the electrochemical reactions on nanoporous electrode surfaces can be controlled by concentration of electrolyte.

Li-Mn계 산화물의 치환 및 첨가에 따른 물성 변화 (Properties Changing depends on Substituents or Dopants of Li-Mn oxide material)

  • 이대진;지미정;최병현
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.289-289
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    • 2007
  • Spinel structured $LiMn_2O_4$ is more economic and environmental friendly to be used as commercial active material for secondary battery compared to Co-oxide material active material, but spinel structure of $LiMn_2O_4$ is unstable and its capacitance decreases with increase of cycle. Therefore, the purpose of our sturdy is to improve the stability of $LiMn_2O_4$ spinel structure and increase its capacitance by using substituents or dopants. $LiMn_2O_4$ powder was synthesized by charging substituents or dopants mole fractions, and temperatures. Crystal state, structure and specific surface area of the synthesized powder were measured and also characteried electrochemically by measuring its impedance, charge-discharge capacitance and etc.

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Ultrahigh supercapacitance in cobalt oxide nanorod film grown by oblique angle deposition technique

  • Kannan, V.;Choi, Jong-Hyeok;Park, Hyun-Chang;Kim, Hyun-Seok
    • Current Applied Physics
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    • 제18권11호
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    • pp.1399-1402
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    • 2018
  • Nanorod films of cobalt oxide ($Co_3O_4$) have been grown by a unique oblique angle deposition (OAD) technique in an e-beam evaporator for supercapacitor electrode applications. This technique offers a non-chemical route to achieve large aspect ratio nanorods. The fabricated electrodes at OAD $80^{\circ}$ exhibited a specific capacitance of 2875 F/g. The electrochemically active surface area was $1397cm^{-2}$, estimated from the non-Faradaic capacitive current region. Peak energy and power densities obtained for $Co_3O_4$ nanorods were 57.7 Wh/Kg and 9.5 kW/kg, respectively. The $Co_3O_4$ nanorod electrode showed a good endurance of 2000 charge-discharge cycles with 62% retention. The OAD approach for fabricating supercapacitor nanostructured electrodes can be exploited for the fabrication of a broad range of metal oxide materials.

고분자 전해질 막 연료전지의 촉매층 내의 나피온 아이오노머양에 따른 단위 셀의 전기화학적 특성 연구 (Nafion Ionomer Content in Catalyst Layer for PEMFC Nafion Ionomer Content in Catalyst Layer for PEMFC)

  • 안경용;양철남;이수
    • 한국수소및신에너지학회논문집
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    • 제21권6호
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    • pp.540-546
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    • 2010
  • In order to confirm the effect of Nafion ionomer content in catalyst layer on the performance of PEMFC, we have fabricated several electrodes which were prepared by varying the quantity of Nafion ionomer from 24 wt.% to 39 wt.% in catalyst layer. The effect of Nafion ionomer of each electrode was evaluated with cyclic voltammetry measurement. In addition, cell performance was obtained through single cell test using hydrogen and air. The Pt utilization and performance of single cell were changed by addition of Nafion ionomer to the electrode. Single cell fabricated with 33 wt.% of Nafion ionomer in catalyst layer showed the maximum Pt utilization and performance.

전기화학적 산화를 위한 삼원 전이 금속 코팅 불용성 산화 전극 제조에 관한 연구 (A Study on the Preparation of Ternary Transition Metal Coated-Dimensionally Stable Anode for Electrochemical Oxidation)

  • 박종혁;최장욱;박진수
    • 공업화학
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    • 제32권4호
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    • pp.409-416
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    • 2021
  • 불용성 산화 전극은 전기화학적 수처리 공정에 있어 가장 핵심적인 소재이며, 이를 이용하여 난분해성 유기물질을 분해하는 방법으로 많은 연구가 진행되어 왔다. 이러한 불용성 산화 전극 제조에 있어 금속 기판 표면에 코팅하는 금속 촉매의 종류, 코팅 방식, 소결 방법 등의 다양한 제조 변수가 불용성 산화 전극의 성능 및 내구성에 영향을 미친다. 본 연구에서는 Ir-Ru-Ta 삼원 금속 코팅을 활용하여 동일한 전 처리 및 소결 조건에서 코팅 방법에 따라 불용성 산화 전극을 제조하고 이의 성능과 내구성을 연구하였다. 코팅 방식은 브러쉬 및 스프레이 코팅법을 활용하였으며, 그 결과 최적화된 스프레이 코팅 조건에서 동일한 촉매 잉크양으로 더 많은 금속을 Ti 기판 표면에 코팅이 가능하여 촉매 잉크 저감이 가능한 것을 확인하였다. 또한, 전극 표면의 갈라짐 현상 및 삼원 금속의 균일한 도포에 의해 스프레이 코팅법으로 제조한 Spray_2.0_3.0 전극이 가장 높은 전기화학적 활성 비표면적을 보여주었으며, 4-chlorophenol의 분해 성능이 타 전극에 비해 우수한 것으로 나타났다. 하지만, 불용성 산화전극의 내구성은 전극의 코팅방법에 따라 큰 차이가 없는 것으로 나타났다.