• 제목/요약/키워드: porous electrode

검색결과 290건 처리시간 0.041초

Synthesis and Characterisation of Mixed Conducting Perovskite Type Oxide and Its Electrochemical Application to Electrode Material for Solid Oxide Fuel Cell

  • Kim, Yu-Mi;Pyun, Su-Il;Lee, Gyoung-Ja;Kim, Ju-Sik
    • 전기화학회지
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    • 제10권2호
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    • pp.116-125
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    • 2007
  • This article is concerned with synthesis, characterisation and electrochemical application of the mixed conducting perovskite type oxide to electrode materials for solid oxide fuel cell. First, this review provides a comprehensive survey of the various synthetic methods such as solid state reaction, Pechini, glycine nitrate process and sol-gel methods for the preparation of perovskite type oxide powders. Subsequently, the electrical and microstructural properties of the mixed conducting oxides were discussed in detail. Finally, as electrochemical applications of the mixed conducting perovskite type oxides to electrode materials for solid oxide fuel cell, fundamentals of theoretical ac-impedance model for porous mixed conducting electrodes were introduced. Furthermore, the ac-impedance behaviour of porous and dense mixed conducting electrodes prepared by various synthetic methods was discussed.

Electrical properties of the Porous polycrystalline silicon Nano-Structure as a cold cathode field emitter

  • Lee, Joo-Won;Kim, Hoon;Lee, Yun-Hi;Jang, Jin;Oh, Myung-Hwan;Ju, Byung-Kwon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.1035-1038
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    • 2002
  • The electrical properties of Porous polycrystalline silicon Nano-Structure (PNS) as a cold cathode were investigated as a function of anodizing condition, the thickness of Au film as a top electrode and the substrate temperature. Non-doped 2${\mu}m$-polycrystalline silicon was electrochemically anodized in HF: ethanol (=1:1) mixture as a function of the anodizing condition including a current density and anodizing time. After anodizing, the PNS was thermally oxidized for 1 hr at 900 $^{\circ}C$. Then, 20nm, 30nm, 45nm thickness of Au films as a top electrode were deposited by E-beam evaporator. Among the PNSs fabricated under the various kinds of anodizing conditions, the PNS anodized at a current density of 10mA/$cm^2$ for 20 sec has the lowest turn-on voltage and the highest emission current than those of others. Also, the electron emission properties were investigated as functions of measuring temperature and the different thickness of Au film as a top-electrode.

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전류세기의 변화에 따른 DBR 다공성 실리콘의 광학적 특성 (Optical Characterization of DBR Porous Silicon by Changing of Applied Current Density)

  • 최태은;박재현
    • 통합자연과학논문집
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    • 제2권2호
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    • pp.82-85
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    • 2009
  • Distributed Bragg reflector (DBR) porous silicon (PSi) was generated by an electrochemical etching a bragg structure into a silicon wafer through electrode current in aqueous ethanolic HF solution. DBR PSi exhibiting unique reflectivity was successfully obtained by an electrochemical etching of silicon wafer using square current waveform. The multilayered photonic crystals of DBR PSi exhibited the reflection of a specific wavelength with high reflectivity in the optical reflectivity spectrum. In this work, we have developed a method to create refractive index in Si substrate through intensity of an electric current. The electrochemical process allows for precise control of the structural properties of DBR PSi such as thickness of the porous layer, porosity, and average pore diameter. The number of reflection peak of DBR PSi and its pore size increased as the intensity of electric current increased. This might be a demonstration for the fabrication of specific reflectors or filters.

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고밀도스트리머를 이용한 $CF_{4}$ 분해특성 (The characteristic of $CF_{4}$ decomposition for High density streamer)

  • 송원섭;박재윤;정장근;김종석;김태용
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 제4회 영호남학술대회 논문집
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    • pp.133-137
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    • 2002
  • In this paper, the $CF_{4}$ decomposition rate are investigated for a simulated three plasma reactors which are metal particle reactor, spiral wire reactor and reactor with porous dielectric as applied voltage. The $CF_{4}$ decomposition rate by plasma reactor with porous dielectric had a gain of 20~25[%] over that by plasma reactor with spiral wire or metal particle electrode. The $CF_{4}$ decomposition efficiency increases with increasing applied voltage up to the critical voltage for spark formation. The $CF_{4}$ decomposition efficiency of metal particle reactor was about 80[%] at AC 24[kV]. However, decomposition efficiency is more than 90% in case of the reactor with porous dielectric. we think, the reactor with porous dielectric should be much better than other reactors for $CF_{4}$ decomposition.

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Electrochemical Dechlorination of 1,2,4-Trichlorobenzene Using a Reticulated Vitreous Carbon Electrode

  • Paeng, Ki-Jung;Lim, Chae-Yun;Lee, Bo-Young;Myung, No-Seung;Rhee Paeng, In-Sook
    • Bulletin of the Korean Chemical Society
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    • 제24권9호
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    • pp.1329-1332
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    • 2003
  • Stepwise dechlorination of 1,2,4-trichlorobenzene was observed at a glassy carbon electrode in dimethylformamide containing 0.1 M tetraethylammonium perchlorate. Especially, dechlorination to dichlorobenzene and further to monochlorobenzene or benzene was successfully demonstrated with a porous reticulated vitreous carbon electrode. Electrochemical dechlorination of polychlorobenzenes employing a flow cell with a reticulated vitreous carbon working electrode is also described. Preliminary experiments with a flow cell showed that dechlorination of trichlorobenzene to dichlorobenzene was partially completed while dechlorination to benzene or monochlorobenzene was not successful, suggesting that a flow rate and electrolysis time should be further optimized for the complete electrolysis.