• Title/Summary/Keyword: 전기화학적 용해

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In-Situ Generation of Nanostructured Au Surfaces by Anodic Dissolution Followed by Cathodic Deposition (산화 용해에 연이은 환원 석출을 통한 나노구조 금 표면 형성)

  • Kweon, Suji;Choi, Suhee;Kim, Jongwon
    • Journal of the Korean Electrochemical Society
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    • v.18 no.3
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    • pp.107-114
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    • 2015
  • Electrochemical fabrication of nanostructured Au surfaces has received increased attention. In the present work, electrochemical modification of Au surfaces for fabricating nanostructured Au surfaces in the absence of externally added precursors is presented, which is different to the previous methods utilizing electrochemical deposition of externally added precursors. Application of anodic potential at Au surfaces in phosphate buffers containing $Br^-$ resulted in the anodic dissolution of Au, which produced Au precursors at the electrode surfaces. The resulting Au precursors were further reduced at the surface to produce nanostructured Au structures. The effects of applied potential and time on the morphology of Au nanostructures were systematically examined, from which a unique backbone type Au nanostructures was produced. The backbone type Au nanostructures exhibited high surface-enhanced Raman activity. The present work would give insights into the formation of electrochemical fabrication of nanostructured Au surfaces.

Trends and Market Outlook in Electrochromic Technology (전기변색기술의 동향 및 시장전망)

  • Ryu, H.J.;Cho, S.M.;Ah, C.S.;Kim, T.Y.;Cheon, S.H.;Kim, J.Y.;Song, J.H.;Kim, Y.H.
    • Electronics and Telecommunications Trends
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    • v.30 no.6
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    • pp.12-20
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    • 2015
  • 전기변색기술은 전기화학적 반응으로 물질의 색을 바꾸는 기술이다. 이 반응에는 전자의 이동이 개입되며 전자의 이동에 따른 화학반응은 일반적인 화학반응과 차이를 나타낸다. 산화와 환원이라는 화학반응은 닫힌 회로 내에서 일어나며 오직 계면에서의 전위에 의존하게 된다. 이러한 전기변색기술을 응용한 분야는 자동차용 전기변색 거울, 스마트 윈도우와 같이 상용화에 성공한 분야도 있으며, 앞으로는 투명 디스플레이, 반사형 디스플레이 및 전가자격표시장치 등에 활용이 가능하다. 전기변색기술이 견인하는 세계시장규모는 에너지 절약 및 안전성에 대한 시대적인 요청으로 연평균 성장률 약 21%로 확대되어 2018년에는 약 50억달러의 규모로 성장할 수 있을 것으로 예측된다.

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Introduction to Electrochemical Quartz Crystal Microbalance Technique for Leaching Study of Metals (금속 침출연구를 위한 전기화학적 미소수정진동자저울 기술 소개)

  • Kim, Min-seuk;Chung, Kyeong Woo;Lee, Jae-chun
    • Resources Recycling
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    • v.29 no.1
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    • pp.25-34
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    • 2020
  • Electrochemical Quartz Crystal microbalance is a tool that is capable of measuring nanogram-scale mass change on electrode surface. When applying alternating voltage to the quartz crystal with metal electrode formed on both sides, a resonant frequency by inverse piezoelectric effect depends on its thickness. The resonant frequency changes sensitively by mass change on its electrode surface; frequency increase with metal dissolution and decrease with metal deposition on the electrode surface. The relationship between resonant frequency and mass change is shown by Sauerbrey equation so that the mass change during metal dissolution can be measured in real time. Especially, it is effective in the case of reaction mechanism and rate studies accompanied by precipitation, volatilization, compound formation, etc. resulting in difficulties on ex-situ AA or ICP analysis. However, it should be carefully considered during EQCM experiments that temperature, viscosity, and hydraulic pressure of solution, and stress and surface roughness can affect on the resonant frequency. Application of EQCM was shown as a case study on leaching of platinum using aqueous chlorine for obtaining activation energy. A platinum electrode of quartz crystal oscillator with 1000 Å thickness exposed to solution was used as leaching sample. Electrogenerated chlorine as oxidant was purged and its concentration was controlled in hydrochloric acid solution. From the experimental results, platinum dissolution by chlorine is chemical reaction control with activation energy of 83.5 kJ/mol.