• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 학술논문집
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• pp.337-337
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• 2004

As one of researches for the P ＆ T purposes, a basic experiment on the recovery of actinide elements from the mixture with rare earth elements by means of electrorefining using a liquid cadmium cathode in the LiCl-KC1 eutectic melt was carried out. In order to examine the behaviors of electrodeposition of metal ions on a liquid electrode, recovery experiments of rare earth metals resulting from forming electrodeposits were performed by a galvanostatic electrolysis method at various current densities. A cyclic voltammetric technique was applied to determine reduction-oxidation potential of each metal element in the melt and to detect the changes of the multi component melt composition for on-line monitoring. Also, a collaboration study with RIAR was completed to test the preliminary feasibility on a recovery of actinide elements from the mixture with rare earth elements using a liquid cadmium cathode and actinide metals. Experimental results showed that the ratio of actinides to rare earths, 9: 0.5∼1 led to the rare earth content of about 5∼10 wt% in the deposit.

• Korean Chemical Engineering Research
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• 제43권5호
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• pp.627-631
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• 2005

고온수증기 전기분해의 양극물질로 이용될 수 있는 $(La_{0.8}Sr_{0.2})_{0.95}MnO_3$/yttria-stabilized zirconia(LSM/YSZ) 복합체 전극을 x-ray diffractometry, scanning electron microscopy 그리고 galvanodynamic, galvanostatic polarization method로 연구하였다. 이런 목적으로 perovskite-type의 LSM 물질은 공침법을 이용하여 제조하였으며, 8 mol% YSZ와 몰분율을 달리하여 복합체 전극을 합성하였다. LSM/YSZ 복합체 전극은 평판의 YSZ 전해질에 LSM/YSZ 복합체를 스크린 프린팅 후 $1,100^{\circ}C$에서 열처리 코팅하여 제조하였다. 실험결과로부터 LSM/YSZ 복합체 전극의 전기화학적 특성은 전극을 이루는 삼상계면의 구조와 전기분해 온도에 영향을 받는다는 것을 확인하였다.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.965-974
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• 2022

Platinum anodes are widely used for metal oxides reduction in LiCl-Li₂O, however high-cost and low-corrosion resistance hinder their implementation. NiO-Li₂O ceramics is an alternative corrosion resistant anode material. Anode processes on platinum and NiO-Li₂O ceramics were studied in (80 mol.%) LiCl-(20mol.%)KCl and (80 mol.%)LiCl-(20 mol.%)KCl-Li₂O melts by cyclic voltammetry, potentiostatic and galvanostatic electrolysis. Experiments performed in the LiCl-KCl melt without Li₂O illustrate that a Pt anode dissolution causes the Pt²⁺ ions formation at 3.14 V and 550℃ and at 3.04 V and 650℃. A two-stage Pt oxidation was observed in the melts with the Li₂O at 2.40 ÷ 2.43 V, which resulted in the Li₂PtO₃ formation. Oxygen current efficiency of the Pt anode at 2.8 V and 650℃ reached about 96%. The anode process on the NiO-Li₂O electrode in the LiCl-KCl melt without Li₂O proceeds at the potentials more positive than 3.1 V and results in the electrochemical decomposition of ceramic electrode to NiO and O₂. Oxygen current efficiency on NiO-Li₂O is close to 100%. The NiO-Li₂O ceramic anode demonstrated good electrochemical characteristics during the galvanostatic electrolysis at 0.25 A/cm² for 35 h and may be successfully used for pyrochemical treating of spent nuclear fuel.

• Bulletin of the Korean Chemical Society
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• 제15권9호
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• pp.739-743
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• 1994

A spectroelectrochemical system assembled with a white light source, bifurcated optical fiber, Oriel Multispec spectrograph, and a charge-coupled device (CCD) detector is described. The system is shown to be capable of acquiring a whole spectrum in the spectral range of 290-800 nm in 25 ms or a longer period during electrochemical experiments at reflective working electrodes such as platinum or mercury. The utility of the system in studying electrochemical reactions during the potential scan, galvanostatic electrolysis, or after the potential step is demonstrated.

• 자원리싸이클링
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• 제16권6호
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• pp.52-60
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• 2007

탈질 특허분석과 전해기초연구를 통하여 수용액으로부터 질소의 환원제거에 대하여 조사하였다. 세계적으로 수용액으로부터 질소를 제거하는 방법으로 생물학적 기술과 산화환원 기술이 개발되고 있으며, 최근 들어 전해기술에 대한 특허출원도 증가하고 있다. 전해법에서 Fe를 음극으로 Pt를 양극으로 채택한 정전류 전해법에 의하여 1시간동안 총질소를 47% 이상 제거할 수 있었다. 질소함유 폐수를 처리하는 효율적인 방법은 폐수 특성에 맞는 기술의 조합이라고 말할 수 있다. 예를 들어 고농도 질소 함유 폐수를 소량 배출하는 경우 화학적 처리와 전해법의 조합으로 질산성 질소를 아질산성 질소로 일차 전환시켜 전해효율을 극대화시키면서 2차 오염원인 용해 금속이온을 전해과정에서 음극에 환원 회수하는 방법 등이 실용화에 유리하다고 말할 수 있다.

• 방사성폐기물학회지
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• 제19권2호
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• pp.161-176
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• 2021

In this study, the electrochemical behavior of Sm on the binary liquid Al-Ga cathode in the LiCl-KCl molten salt system is investigated. First, the co-reduction process of Sm(III)-Al(III), Sm(III)-Ga(III), and Sm(III)-Ga(III)-Al(III) on the W electrode (inert) were studied using cyclic voltammetry (CV), square-wave voltammetry (SWV) and open circuit potential (OCP) methods, respectively. It was identified that Sm(III) can be co-reduced with Al(III) or Ga(III) to form Al_zSm_y or Ga_xSm_y intermetallic compounds. Subsequently, the under-potential deposition of Sm(III) at the Al, Ga, and Al-Ga active cathode was performed to confirm the formation of Sm-based intermetallic compounds. The X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analyses indicated that Ga₃Sm and Ga₆Sm intermetallic compounds were formed on the Mo grid electrode (inert) during the potentiostatic electrolysis in LiCl-KCl-SmCl₃-AlCl₃-GaCl₃ melt, while only Ga₆Sm intermetallic compound was generated on the Al-Ga alloy electrode during the galvanostatic electrolysis in LiCl-KCl-SmCl₃ melt. The electrolysis results revealed that the interaction between Sm and Ga was predominant in the Al-Ga alloy electrode, with Al only acting as an additive to lower the melting point.

• Advances in Energy Research
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• 제3권1호
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• pp.45-57
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• 2015

This article is addressed to define a new composite electrode constituted by porous nickel and an array of highly ordered $TiO_2$ nanotubes obtained by a previous galvanostatic anodization treatment in an ethylene glycol solution. The electrochemical performances of the composite anode were evaluated in a photo-electrolyser, which showed good solar conversion efficiency with respect to the UV irradiance together with a reduction of energy consumption. Such a combination of materials makes our system simple and able to work both in dark and under solar light exposure, thus opening new perspectives for industrial-scale applications.

• 공업화학
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• 제8권5호
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• pp.784-789
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• 1997

전도성 고분자인 폴리피롤(PPy)을 전해질로 하는 알루미늄(Al)고체전해 캐패시터를 제작하기 위하여 알루미늄 산화피막($Al_2O_3$) 위에 화학산화중합(CP)법으로 얇은 PPy층을 형성시키고, 이 층을 양극으로 이용하여 피롤(Py)을 전해산화중합(EP)시켰다. 캐패시터 특성에 영향을 미치는 중합조건을 조사한 결과, 지지전해질로서 sodium p-toluenesulfonate (TsONa)를 사용하고, 소자당 2.0~4.0 mA의 정전류를 인가, 전해중합 후 제작한 캐패시터의 전기적 특성 및 임피던스 특성이 가장 우수하였다.

• 한국표면공학회지
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• 제49권2호
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• pp.125-129
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• 2016

Anodizing is a technology to generate thicker and high-quality films than natural oxide films by treating metals via electrochemical methods. Electrochemical manufacturing method of nano structure is an efficient technology in terms of cost reduction, high productivity and complicated shapes, which receives the spotlight in diverse areas. Especially, artificial films generated by anodizing technology possess excellent mechanical characteristics including hardness and wear resistance. It is also easy to modify thickness and adjust shape of those artificial films so that they are mainly used in sensors, filters, optical films and electrolytic condensers. In this study, experiment was performed to observe the effect of current density on porous film formation in two-step anodizing for Al alloy. Anodizing process was performed with 10 vol.% sulfuric acid electrolyte while the temperature was maintained at $10^{\circ}C$ using a double beaker. and $10{\sim}30mA/cm^2$ was applied for 40 minutes using a galvanostatic method. As a result, both pore diameters and distances between pores tended to increase as the local temperature and electrolysis activity increased due to the increase in applied current density.

• 대한화학회지
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• 제21권6호
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• pp.404-412
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• 1977

에탄올-물 혼합용매에서 납전극을 사용하여 니트로벤젠(${\phi}NO_2$)과 그 유도체의 전해 환원반응을 조사하였다. 산성용액에서는 퍼텐셜에 따라 ${\phi}NHOH\;및\;{\phi}NH_2$가 생성되었으며 니트로벤젠(${\phi}NO$)은 중간체가 아닌것으로 보였다. 염기성 용액에서는 ${\phi}NO$가 생성되며 더 낮은 퍼텐셜에서 환원시키면 ${\phi}N=N{\phi}$ 등 짝지어진 화합물이 생성됨을 확인하였다. 사용한 전해질 용액에서 ${\phi}NO\;와\;{\phi}NHOH$ 사이에 화학적인 짝지음 반응(coupling reaction)은 일어나지 않았다. 각각의 반응에 대해 전류-전압관계와 pH 의존도 및 반응물질에대한 반응 차수로부터 반응 메카니즘을 도출하였다. ${\phi}NO$가 생성되는 반응은 치환기가 있을 때도 같은 메카니즘을 따르는 것으로 보인다.