• Title/Summary/Keyword: Electrode density

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Decolorization of a Rhodamine B Using Ru-graphite Electrode (Ru-흑연 전극을 이용한 Rhodamine B의 색 제거)

  • Park, Young-Seek
    • Journal of Environmental Science International
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    • v.17 no.5
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    • pp.547-553
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    • 2008
  • For the RhB removal from the wastewater, electrochemical method was adapted to this study. Three dimensionally stable anode (Pt, Ir and Ru) and graphite and Ru cathode were used. In order to identify decolorization, the effects of electrode, current density, electrolyte and air flow rate were investigated. The effects of electrode material, current, electrolyte concentration and air flow rate were investigated on the decolorization of RhB. Electro-Fenton's reaction was evaluated by added $Fe^{2+}$ and $H_2O_2$ generated by the graphite cathode. Performance for RhB decolorization of the four electrode systems lay in: Ru-graphite > Ru-Ru > Ir-graphite > Pt-graphite. A complete color removal was obtained for RhB (30 mg/L) at the end of 30 min of electrolysis under optimum operations of 2 g/L NaCl concentration and 2 A current. $Fe^{2+}$ addition increased initial reaction and decreased final RhB concentration. However the effect was not high.

Preperation of catalyst having high activity on oxygen reduction (저온형 연료전지용 산소의 고활성 환원 촉매 제조)

  • 김영우;김형진;이주성
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1992.11a
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    • pp.39-40
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    • 1992
  • This paper dealt with the manufacturing of binary alloy catalyst and showed simple electrochemical method for determing catalytic activity of oxygen reduction in acid or alkaline electrolyte. The catalyst was prepared by impregnating transition metal salts on platinum or silver particles adsorbed before on carbon paper substrate. The electrochemical characteristics of the catalysts was investigated with carbon paper electrode or PTFE-boned porous electrode and then cathodic current densities and tafel slopes were compared. As a result, of all binary catalysts utilized in this work, Pt-Fe, Pt-Mo showed better oxygen reduction activity than pure platinum catalyst in acid electrolyte and Ag-Fe, Ag-Pt, and Ag-Ni-Bi-Ti catalyst did than pure silver catalyst in alkaline electrolyte. The current density of Pt-Fe electrode in acid electrolyte was one and half times higher than that of Pt electrode(~500mA/$\textrm{cm}^2$ at 0.7VvsNHE).

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Study on the Electrical Stability of Al-doped ZnO Thin Films For OLED as an alternative electrode

  • Jung, Jong-Kook;Lee, Seong-Eui;Lim, Sil-Mook;Lee, Ho-Nyeon;Lee, Young-Gu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1469-1472
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    • 2006
  • We investigated the electrical and optical properties of ZnO:Al thin films as a function of the thermal process conditions. The film was prepared by RF magnetron sputtering followed by annealing in a box furnace in air. An ZnO:Al (98:2) alloy with the purity of 99.99% (3 inch diameter) was used as the target material. The electrical properties of the transparent electrode, exhibited surface oxidation as a result of rapid oxygen absorption with increasing annealing temperature. The processed ZnO:Al films and commercial ITO(indium-tin-oxide) were applied to an OLED stack to investigate the current density and luminescence efficiency. The efficiency of the device using the ZnO:Al electrode was higher than that from the device using the ITO electrode.

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The Properties of the Metal Hydride electrodes prepared by Silicon Sealant (Si-sealant를 이용하여 제조한 금속수소화물 전극의 특성)

  • CHOI, Jeon;PARK, Choong-Nyeon
    • Transactions of the Korean hydrogen and new energy society
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    • v.4 no.2
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    • pp.23-28
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    • 1993
  • The $(LM)Ni_{4.5}Co_{0.1}Mn_{0.2}Al_{0.2}$ hydrogen storage alloy powders were conducted 25wt% electroless copper plating in an acidic bath. For the preparation of a hydride electrodes, the copper coated alloy powder was mixed with Si-sealant(organosilicon) and compacted with $6t/cm^2$ at room temperature. The electrode characteristics were examined through electrochemical measurements in a half cell. As a sealant contents increased, the initial discharge capacity of si-sealant bounded electrode was lower and the activation rate in high current density was slower. For extended cycles, however, the electrodes with the Si-sealant were superior in a high rate discharge and useful range of temperature over the sealant-free electrode. In addition, the cycle life increased with increasing the amount of Si-sealant added. It can be suggested from the results that the Si-sealant as a binder could be applied to the preparation of the metal hydride electrode.

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Characteristics of high energy density hybrid capacitor using metal oxide electrode (금속산화물 전극을 사용한 고 에너지밀도 하이브리드 커패시터 특성)

  • Yoon, Hong-Jin;Shin, Yoon-Sung;Lee, Jong-Dae
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.3
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    • pp.329-334
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    • 2011
  • The electrochemical performances of an asymmetric hybrid capacitor were investigated using $LiFePO_4$ as the positive electrode and active carbon fibers(ACF) as the negative electrode. The electrochemical behaviors of a nonaqueous hybrid capacitor were characterized by constant current charge/discharge test. The specific capacitance using $LiFePO_4$/ACF electrode turned out to be $0.87F/cm^2$ and the unit cell showed excellent cycling performance. This hybrid capacitor was able to deliver a specific energy as high as 178 Wh/kg at a specific power of 1,068 W/kg.

Electrochemical Investigation of Animal Tissue Embedded Biosensor Bound with Ethylene-Propylene Rubber

  • Yoon, Kil-Joong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.10
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    • pp.2913-2917
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    • 2010
  • When rubber dissolved in toluene was used as a binding material of graphite powder, the mechanical robustness of the carbon paste was guaranteed by the fast volatility of the solvent immediately after electrode construction. This characteristic of the rubber solution met qualifications for practical use of carbon paste electrodes and enabled the design of a new enzyme electrode bound with EPDM. In order to confirm whether the electrode shows quantitative electrochemical behaviors or not, its kinetic parameters, e. g. the symmetry factor (0.2), the exchange current density ($3.66\;{\mu}A/cm^2$), the capacity of the double layer ($2.0{\times}10^{-5}\;F$), the Michaelis constant ($4.39{\times}10^{-3}\;M$), the diffusion coefficient of substrate ($2.58{\times}10^{-12}\;cm^2/sec$), the time constant (0.018 sec) and other factors were investigated.

Electrochemical Properties of Electric Double Layer Capacitor with PolyanilineComposite (Polyaniline Composite 전극을 사용한 전기 이중층 캐패시터의 전기화학적 특성)

  • 강광우;김종욱;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.370-373
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    • 1999
  • The purpose of this study is to research and develop PAn composite electrode for EDLC. EDLC cell of PAn composite electrode with 1M LiClO$_4$/PC brings out good capacitor performance below 4.0V. The radius of semicircle of PAn composite electrode adding 15wt% SP270 was absolutely small. The total resistance of EDLC cell mainly depended on internal resistance of the electrode. The discharge capacitance of PAn composite with 15wt% SP270 in 1st and 200th cycles was 42 and 42 F/g at current density of 1mA/cm$^2$. The capacitance of PAn composite with 15wt%. SP270 capacitor was larger than that of PAn capacitor without SP270. The coulombic efficiency of EDLC at discharge process of 1 and 200 cycles were 94 and 100% respectively. PAn composite EDLC with 15wt% SP270 content showed good capacitance and stability with cycling.

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Oil Movement Control by Charge Density Control in the Electrowetting Display (하전입자의 분포에 따른 Electrowetting display의 오일의 움직임)

  • Kim, Tae-Hyun;Kim, Yeon-Sik;Ashanulhaq, Q.;Jeong, Eun;Hahn, Yoon-Bong;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.495-496
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    • 2006
  • Electrowetting phenomenon is applied in the various field of technology. One of that is electrowetting display as a paper like electronic paper. Fast response and easy to express a color is goodness. In spite of that, the oil movement of the electrowetting display is irregular. So it doesn't look like uniform. Because of above reason, electrowetting display using patterned electrode is made and the characteristic of oil movement is observed. Electrode and polymer wall is patterned by photo-lithography. We analyze the oil movement according to the variation of size and the position of etched electrode area.

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The Effect of Electrode Spacing and Size on the Performance of Soil Microbial Fuel Cells (SMFC) (전극간 거리와 크기가 토양미생물연료전지의 성능에 미치는 영향)

  • Im, Seong-Won;Lee, Hye-Jeong;Chung, Jae-Woo;Ahn, Yong-Tae
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.11
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    • pp.758-763
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    • 2014
  • Soil microbial fuel cells (SMFC) have gained a great attention as an eco-friendly technology that can simultaneously generate electricity and treat organic pollutants from the contaminated soil. We evaluated the effect of electrode spacing and size on the performance of SMFC treating soil contaminated with organic pollutants. Maximum power density decreased with increase in electrode distance or decrease in electrode size, likely due to higher internal resistance. The maximum voltage and power density decreased from 326 mV and $19.5mW/m^2$ with 4 cm of electrode distance to 222 mV and $5.9mW/m^2$ with 9 cm of electrode distance. In case of electrode size test, the maximum voltage and power density generated was 291 mV, $0.34mW/m^3$ when both of anode and cathode area were $64cm^2$ with 4 cm of electrode distance. The maximum voltage decreased by 19~29% when the anode area decreased to $16cm^2$ while only 3~12% of voltage decreased with cathode area decrease. The maximum power density decreased by 49~68% with decreasing anode size, and by 29~47% with decreasing cathode size. These results showed that the anode area had more significant effects than the cathode area on the power generation of SMFC which has a high internal resistance due to a coexistence of soil and wastewater in the reactor.

A study on the analysis of carrier properties and trap energy depth in the low-density polythylene electrets (저밀도 폴리에틸렌 일렉트렉트에 있어서 케리어의 성질과 Trap 깊이 해석에 대한 연구)

  • 이준웅
    • 전기의세계
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    • v.29 no.8
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    • pp.511-518
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    • 1980
  • The thermostimulated discharge currents of low-density polyethylene electrets were measured versus the principal experimental variables. Several electrode types were used for the charging and discharging procedures. The results led to know the experimental conditions for the heterocharge and homocharge accumulating and decreasing. The electronic structure parameters of polyethylene such as trap level, density of traps, hopping length, mobility, trap time constants were deduced. A method for evaluating the local electric field inside the electret is proposed.

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