• 센서학회지
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• 제8권3호
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• pp.247-252
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• 1999

바이오센서로 이용되는 산소센서에는 효소고정화막과 함께 반투성막이 필요한데, 이러한 두 층의 막은 취급이 쉽지 않아서 상업화하기가 불리하므로, 이 두 막을 하나의 적층막으로 제조하였다. cellulose triacetate/polycarprolactone(CTA/PCL)막에 1,1'-carbonyl diimidazole(CDI) 방법으로 glucose oxidase, ascorbate oxidase, pyrubate oxidase와 alcohole oxidase 등의 효소를 고정화시킨 다음, 그 위에 polyvinylalcohol을 알데하이드와 산과 혼합하여 적층방법으로 단일막을 제조하였다. 고정화된 이 적층막을 산소전극에 부착하여 glucose, ascorbate, pyrubate, ethanol의 농도에 따른 전류변화를 측정한 결과, 각각 5-10mmol 이내의 기질농도에서 $0.38{\sim}0.83{\mu}A$까지 r=0.995의 선형성을 나타내었다. 한편, 고정화된 적층막의 저장중 안정성은 glucose oxidase는 8주 후에도 56% 이상의 활성을 나타내고 있었으나 나머지 효소들은 효소의 안정성이 낮았다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.198-201
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• 2001

The mixed gas of Hydrogen and Oxygen is gained from water electrolysis reaction. It has constant volume ratio 2 : 1 Hydrogen and Oxygen, and it is used as a source of thermal energy by combustion reaction. This gas has better characteristics in the field of economy, efficiency of energy, and environmental intimacy than acetylene gas and LPG used for gas welding machine. So several studies of this gas are actively in progress nowadays. The object of this study is the optimization of power condition in the side of electrical for the high efficiency of water electrolysis equipment. First, chemical analysis of electrolysis is conducted, and the relation of electrical energy and chemical energy is quantitatively investigated. For basic experiment, unit electrode of singular electrolysis electrode is manufactured and experimented, results are compared and analyzed with simulation, and the electrolysis is electrically equivalent.

• Journal of Electrochemical Science and Technology
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• 제14권3호
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• pp.215-221
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• 2023

A rapid and environment-friendly electrochemical sensor to determine the chemical oxygen demand (COD) has been developed. The boron-doped diamond (BDD) thin-film electrode is employed as the anode, which fully oxidizes organic pollutants and provides a current response in proportion to the COD values of the sample solution. The BDD-based amperometric COD sensor is optimized in terms of the applied potential and the solution pH. At the optimized conditions, the COD sensor exhibits a linear range of 0 to 80 mg/L and the detection limit of 1.1 mg/L. Using a set of model organic compounds, the electrochemical COD sensor is compared with the conventional dichromate COD method. The result shows an excellent correlation between the two methods.

• Journal of Electrochemical Science and Technology
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• 제14권3호
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• pp.243-251
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• 2023

Developing oxygen evolution reaction (OER) electrocatalysts is essential to accomplish viable CO₂ and water electrolysis. Herein, we report the fabrication and OER performance of Ni-foam (NF)-immobilized Ni₆ nanoclusters (NCs) (Ni₆/NF) prepared by a dip-coating process. The Ni₆/NF electrode exhibited a high current density of 500 mA/cm² for the OER at an overpotential as low as 0.39 V. Ni₆/NF exhibited high durability in an alkaline solution without corrosion. Electrokinetic studies revealed that OER can be easily initiated on Ni6 NC with fast electron-transfer rates. Finally, we demonstrated stable CO₂-to-CO electroreduction using an NC-based zero-gap CO₂ electrolyzer operated at a current density of 100 mA/cm² and a full-cell potential of 2.0 V for 12 h.

• 멤브레인
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• 제32권1호
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• pp.43-49
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• 2022

높은 안전성과 견고한 기계적 특성을 가진 고체상 슈퍼커패시터는 차세대 에너지 저장 장치로서 세계적 관심을 끌고 있다. 슈퍼커패시터의 전극으로서 경제적인 탄소 기반 전극이 많이 사용되는데 수계 전해질을 도입하는 경우 소수성 표면을 가진 탄소 기반 전극과의 계면 상호성이 좋지 않아 저항이 증가한다. 이와 관련하여 본 연구에서는 전극 표면에 산소 플라즈마 처리를 하여 친수화된 전극과 수계 전해질 사이의 향상된 계면 성질을 기반으로 더 높은 전기화학적 성능을 얻는 방법을 제시한다. 풍부해진 산소 작용기들로 인한 표면 친수화 효과는 접촉각 측정을 통해 확인하였으며, 전력과 지속시간을 조절함으로써 친수화 정도를 손쉽게 조절할 수 있음을 확인하였다. 수계 전해질로 PVA/H₃PO₄ 고체상 고분자 전해질막을 사용하였으며 프레싱하여 전극에 도입하였다. 15 W의 낮은 전력으로 5초간 산소 플라즈마 처리를 시행하는 것이 최적 조건이었으며 슈퍼커패시터의 에너지 밀도가 약 8% 증가하였다.

• 조명전기설비학회논문지
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• 제25권9호
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• pp.80-85
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• 2011

In this paper, complex discharge type ozonizer with a screw type electrode has been designed and manufactured for environmental improvement using low power and high efficency ozoniazer. The complex discharge type ozonizer is equipped with three electrodes{central electrode(CE), internal electrode(IE) and external electrode(EE)}. Ozone of the complex discharge type ozonizer is generated by superposition of silent discharge and surface discharge in discharge space as a screw type CE and IE are respectively applied to AC high voltage of inverse-polarity has $180[^{\circ}]$ phase difference, EE is common electrode. In this time, when oxygen has been used as supplied gas, the maximum values of ozone concentration, ozone generation and ozone yield were obtained as 8,334[ppm], 3,249[mg/h] and 65.3[g/kwh].

• Bulletin of the Korean Chemical Society
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• 제19권7호
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• pp.754-760
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• 1998

It was found that the adsorption of a cobalt(III) complex with a macrocyclic ligand, C-meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (hmc), was induced on a glassy carbon electrode by heavily oxidizing the electrode surface. Adsorption properties are discussed. The glassy carbon electrode with the adsorbed complex was employed to see the catalytic activities for the electro-reduction of O2. In the presence of oxygen, reduction of (hmc)Co3+ showed two cathodic waves in cyclic voltammetry. Compared to the edge plane graphite electrode at which two cathodic waves were also observed in a previous study, catalytic reduction of O2 occurred in the potential region of the first wave while it happened in the second wave region with the other electrode. A rotating disk electrode after the same treatment was employed to study the mechanism of the O2 reduction and two-electron reduction of O2 was observed. The difference from the previous results was explained by the different reactivity of the (hmc)CoOOH2+ intermediate, which is produced after the two electron reduction of (hmc)Co3+ in the presence of O2.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.354-357
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• 2002

Thermally grown gate oxide on 4H-SiC wafer was investigated. The oxide layers were grown at l150$^{\circ}C$ varying the carrier gas and post activation annealing conditions. Capacitance-Voltage(C-V) characteristic curves were obtained and compared using various gate electrode such as Al, Ni and poly-Si. The interface trap density can be reduced by using post oxidation annealing process in Ar atmosphere. All of the samples which were not performed a post oxidation annealing process show negative oxide effective charge. The negative oxide effective charges may come from oxygen radical. After the post oxidation annealing, the oxygen radicals fixed and the effective oxide charge become positive. The effective oxide charge is negative even in the annealed sample when we use poly silicon gate. Poly silicon layer was dope by POCl$_3$ process. The oxide layer may be affected by P ions in poly silicon layer due to the high temperature of the POCl$_3$ doping process.

• 한국수소및신에너지학회논문집
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• 제12권3호
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• pp.231-238
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• 2001

Electrocatalytic activity of palladium for hydrogen oxidation and reduction was studied using AC impedance method. The system under study was arranged in electrolytic mode consisting of Pd electrode under study, Pt counter electrode and Nafion electrolyte between them. Two types of Pd electrodes were used - carbon-supported Pd (Pd/C) and Pd foil electrode. Pd/C anode contacting pure hydrogen showed a steady decrease of charge transfer resistance with the increase of anodic overpotential, which is an opposite trend to that found with Pd foil anode. But Pd foil cathode also exhibited a decrease of the resistance with the increase of cathodic overpotential. The relationship between imposition of overpotential and subsequent change of the charge transfer resistance is determined by the ratio of the rate of faradaic process to the rate of mass transportation; if mass transfer limitation holds, increase of overpotential accompanies the increase of charge transfer resistance. Regardless of the physical type of Pd electrode, the anode contacting hydrogen/oxygen gas mixture did not reveal any independent arc originated from local anodic oxygen reduction.

• 한국수소및신에너지학회논문집
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• 제32권4호
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• pp.256-262
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• 2021

A carbon felt electrode was prepared using ozone and ammonia sequential treatment and applied as an electrode for a vanadium redox flow battery (VRFB). The physical and electrochemical analyses demonstrate that the oxygen groups facilitate nitrogen doping in the carbon felt. Carbon felt (J5O3+NH3), which was subjected to ammonia heat treatment after ozone treatment, showed higher oxygen and nitrogen contents than carbon felt (J5NH3+O3), which was subjected to ammonia heat treatment first and then ozone treatment. From the charging/discharging of VRFB, the J5O3+NH3 carbon felt electrode showed 14.4 Ah/L discharge capacity at a current density of 150 mA /cm², which was 15% and 33% higher than that of J5NH3+O3 and non-activated carbon felt (J5), respectively. These results show that ozone and ammonia sequential treatment is an effective carbon felt activation method to increase the performance of the vanadium redox flow battery.