Methodological Consideration on the Prediction of Electrochemical Mechanical Polishing Process Parameters by Monitoring of Electrochemical Characteristics of Copper Surface

Seo, Yong-Jin The Korean Electrochemical Society 2020 Journal of electrochemical science and technology Vol.11 No.4

The removal characteristics of copper (Cu) from electrochemical surface by voltage-activated reaction were reviewed to assess the applicability of electrochemical-mechanical polishing (ECMP) process in three types of electrolytes, such as HNO₃, KNO₃ and NaNO₃. Electrochemical surface conditions such as active, passive, transient and trans-passive states were monitored from its current-voltage (I-V) characteristic curves obtained by linear sweep voltammetry (LSV) method. In addition, the oxidation and reduction process of the Cu surface by repetitive input of positive and negative voltages were evaluated from the I-V curve obtained using the cyclic voltammetry (CV) method. Finally, the X-ray diffraction (XRD) patterns and energy dispersive spectroscopy (EDS) analyses were used to observe the structural surface states of a Cu electrode. The electrochemical analyses proposed in this study will help to accurately control the material removal rate (MRR) from the actual ECMP process because they are a good methodology for predicting optimal electrochemical process parameters such as current density, operating voltage, and operating time before performing the ECMP process.

과황산염과 나노영가철을 이용한 페놀의 전기화학적 산화

김철용,안준영,김태유,황인성,Kim, Cheolyong,Ahn, Jun-Young,Kim, Tae Yoo,Hwang, Inseong 한국지하수토양환경학회 2017 지하수토양환경 Vol.22 No.2

The efficiency and mechanism of electrochemical phenol oxidation using persulfate (PS) and nanosized zero-valent iron (NZVI) were investigated. The pseudo-first-order rate constant for phenol removal by the electrochemical/PS/NZVI ($1mA^*cm^{-2}/12$ mM/6 mM) process was $0.81h^{-1}$, which was higher than those of the electrochemical/PS and PS/NZVI processes. The electrochemical/PS/NZVI system removed 1.5 mM phenol while consuming 6.6 mM PS, giving the highest stoichiometric efficiency (0.23) among the tested systems. The enhanced phenol removal rates and efficiencies observed for the electrochemical/PS/NZVI process were attributed to the interactions involving the three components, in which the electric current stimulated PS activation, NZVI depassivation, phenol oxidation, and PS regeneration by anodic or cathodic reactions. The electrochemical/PS/NZVI process effectively removed phenol oxidation products such as hydroquinone and 1,4-benzoquinone. Since the electric current enhances the reactivities of PS and NZVI, process performance can be optimized by effectively manipulating the current.

The use of polymer/carbon based material as an efficient and low‑cost electrochemical sensor for rapid electrochemical detection of dopamine

Merve Akin,Ramazan Bayat,Muhammed Bekmezci,Zeynep Kazel Coguplugil,Fatih Sen,Mehdi Baghayeri,Afsaneh Kaffash,Fatemah Tehranejad‑Javazmi,Iran Sheikhshoaie 한국탄소학회 2023 Carbon Letters Vol.33 No.7

In this research, reduced graphene oxide/polypyrrole (rGO/PPy) particles were synthesized and used to measure the amount of dopamine (DA) electrochemically. The obtained rGO/PPy particle was characterized by Fourier Transform Infrared Spectrophotometer (FTIR), UV–Visible Spectrophotometer (UV–Vis), and X-Ray Diffraction Diffractometry (XRD). To investigate the DA sensor performance, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to acquire electrochemical measurements of the sensor. Current values of 1.65 and 5.9 mA were observed in the CV at 0.2 mM and 1.2 mM concentrations of target molecule, respectively. Under optimized conditions, the linear calibration plots were found to exhibit significant sensitivity in the linear range of 0.2 and 1.2 mM, with a corresponding detection limit of 0.061 μM for DA. The results obtained were similar to the sensor results of DA made using precious metals. This work was a demonstration of the feasibility of high-sensitivity electrochemical analysis with conductive carbon materials without the use of precious metals. It was also observed that the cost-effective rGO/PPy exhibited a very high potential for DA detection.

Copper selenide film electrodes prepared by combined electrochemical/chemical bath depositions with high photo-electrochemical conversion efficiency and stability

Zyoud, Ahed,Murtada, Khaled,Kwon, Hansang,Choi, Hyun-Jong,Kim, Tae Woo,Helal, Mohammed H.S.,Faroun, Maryam,Bsharat, Heba,Park, DaeHoon,Hilal, Hikmat S. Elsevier 2018 SOLID STATE SCIENCES Vol.75 No.-

<P><B>Abstract</B></P> <P>Copper selenide (of the type Cu<SUB>2-x</SUB>Se) film electrodes, prepared by combined electrochemical (ECD) followed by chemical bath deposition (CBD), may yield high photo-electrochemical (PEC) conversion efficiency (∼14.6%) with no further treatment. The new ECD/CBD-copper selenide film electrodes show enhanced PEC characteristics and exhibit high stability under PEC conditions, compared to the ECD or the CBD films deposited separately. The electrodes combine the advantages of both ECD-copper selenide electrodes (in terms of good adherence to FTO surface and high surface uniformity) and CBD-copper selenide electrodes (suitable film thickness). Effect of annealing temperature, on the ECD/CBD film electrode composition and efficiency, is discussed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Copper selenide film electrodes have been prepared by ECD followed by CBD. </LI> <LI> The pristine ECD/CBD electrodes exhibit high PEC conversion efficiency and stability with no further treatment. </LI> <LI> The new film combines advantages of both ECD and CBD prepared films. </LI> <LI> ECD/CBD film annealing at 250 °C affects its composition, uniformity and PEC characteristics. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Spectral and photo-electrochemical characteristics for copper selenide film electrodes are enhanced by combining electrochemical and chemical depositions. Plots are measured for (1) Electrochemical deposited, (2) Chemical bath deposited and (3) combined electrochemical & chemical bath deposited film electrodes.</P> <P>[DISPLAY OMISSION]</P>

탄소중립을 지향하는 전기화학적 이온 분리(EIONS) 기술

주화주 ( Hwajoo Joo ),안재욱 ( Jaewuk Ahn ),전성일 ( Sung-il Jeon ),윤제용 ( Jeyong Yoon ) 한국공업화학회 2023 공업화학 Vol.34 No.4

탄소중립 달성을 위해 에너지 효율적이고 전기화된 사회에 직접 이용될 수 있는 친환경 공정이 주목받고 있다. 다량의 에너지를 소모하는 기존의 열 및 압력 기반의 담수화 기술에서도 이는 예외가 아니기에, 최근 차세대 전기화학 기반 담수화 기술들의 성장이 두드러진다. 대표적으로 에너지 저장 장치의 구동 원리를 기반으로 하는 전기화학적 이온 분리(electrochemical ion separation, EIONS) 기술이 있으며, 여기에는 축전식 탈염(CDI) 기술과 배터리 담수화 시스템(BD)가 포함된다. EIONS 기술에는 시스템 성능 향상을 위해 CDI와 BD를 기본으로 한 다양한 응용 시스템들이 개발되어 왔는데, 이러한 결과물들의 의미와 독창성을 배경지식 없이 한눈에 파악하기 매우 어렵다. 따라서 우리는 이 리뷰 논문에서 EIONS 연구에서의 지난 몇 년간의 기술적 진보와 시스템 개별 특성을 각 시스템의 구동원리, 연구배경, 장단점을 중심으로 명확하고 구체적으로 설명하고자 한다. 아울러, EIONS의 미래 발전과 연구 방향을 설명하며 리뷰 논문을 마무리하겠다. 이 논문을 통해 EIONS 연구를 막 시작하는 연구자들이 EIONS의 연구 동향을 보다 쉽게 파악할 수 있을 것이다. Recently, green processes that can be directly used in an energy-efficient and electrified society to achieve carbon neutrality are attracting attention. Existing heat and pressure-based desalination technologies that consume tremendous amounts of energy are no exception, and the growth of next-generation electrochemical-based desalination technologies is remarkable. One of the most representative electrochemical desalination technologies is electrochemical ion separation (EIONS) technology, which includes capacitive desalination (CDI) and battery desalination (BD) technology. In the research field of EIONS, various system applications have been developed to improve system performance, such as capacity and cyclability. However, it is very difficult to understand the meaning and novelty of these applications immediately because there are only a few papers that summarize the research background for domestic readers. Therefore, in this review paper, we aim to describe the technological advances and individual characteristics of each system in clear and specific detail about the latest EIONS research. The driving principle, research background, and strengths and weaknesses of each EIONS system are explained in order. In addition, this paper concluded by suggesting the future development and research direction of EIONS. Researchers who are just beginning out in EIONS research can also benefit from this study because it will help them understand the research trend.

PCR Chip-adopted Electrochemical Biosensor Module for Diagnosis of Infectious Diseases

Won Jae KIM,Jun Yeong JANG,Min Kyung KIM,Jae Hee WON,Chae Min KIM,Minsub CHUNG 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10

Diagnostic technology has been rapidly innovated in speed, accuracy, and economy with the goal of suppressing and preventing the SARS-CoV-2 virus. The currently used diagnostic method is based on optical analysis, which is bulky and expensive. Label-free electrochemical diagnostic biosensor is a promising alternative since measuring electrical signals is significantly cheaper and simpler than the optical apparatus. By combining electrochemistry and PCR mechanisms, high economic efficiency and accuracy can be achieved at the same time. When an electrochemical probe is inserted in the PCR reaction tube and electrochemical measurement is performed, the precipitation by-products generated during the DNA amplification process are adsorbed on the surface of the metal sensor. The chemical change is easy to measure electrochemically. In this study, a module that enables impedance analysis during the PCR process is designed and fabricated. In order to simultaneously perform electrochemical analysis and PCR, sealing is essential when the sensor probe is inserted. Various types of module design was examined. The effect of the material for the sensor probe and PCR amplification chamber was analysed, and PCR amplification through electrochemistry was confirmed by gel-electrophoresis. The developed biosensor system will enable label-free, rapid, and affordable detection system for various infectious diseases.

전기화학적 전착에 의한 ZnSe박막 구조 및 발광특성

김환동,최길호,윤도영,Kim, Hwan-Dong,Choi, Kil-Ho,Yoon, Do-Young 한국반도체디스플레이기술학회 2008 반도체디스플레이기술학회지 Vol.7 No.4

Thin film has been an increasing important subject of intensive research, owing to the fact that these films possess desirable optical, electrical and electrochemical properties for uses in many semi-conducting nano-crystal applications, such as light-emitting diodes, lasers and solar cell applications. Here, ZnSe thin films were deposited by electrochemical method for the applications of light emitting diode. Electrochemical deposition of ZnSe thin film is not easy, because of the high difference of reduction potential between zinc ion and selenium acid. In order to handle the band gap of ZnSe crystal thin films easily, electrochemical methods are promising to manufacture these films economically. Therefore we have investigated the present study to characterize zinc selenide thin films deposited on ITO glass plates electrochemically. The luminescent properties of ZnSe films have been evaluated by UV-Vis spectrometer and luminescence spectrometer. And the morphology of the film surface has been discussed qualitatively from SEM images.

Voltage-Dependent Electrochemical Removal of Copper in KNO3 Electrolytes for Electrochemical-Mechanical Polishing Applications

서용진,한상준,이우선 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

In this paper, the voltage-activated electrochemical reactions of Cu for electrochemical- mechanical polishing (ECMP) applications were investigated for dierent concentrations of the KNO3 electrolyte. The electrochemical characteristics of Cu, such as active, passive, transient and transpassive states, were evaluated from the current-voltage (I-V ) curve obtained by using linear sweep voltammetry (LSV) and cyclic voltammetry (CV). Finally, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diraction (XRD) analyses were utilized to observe the structural surface states of a Cu disk. The proposed mechanism and analyses were a good methodology for finding suitable electrochemical process parameters for ECMP applications.

Effects of the Polarization Resistance on Cyclic Voltammograms for an Electrochemical-Chemical Reaction

Chang, Byoung-Yong The Korean Electrochemical Society 2015 Journal of electrochemical science and technology Vol.6 No.4

Here I report an electrochemical simulation work that compares voltammetric current and resistance of a complex electrochemical reaction over a potential scan. For this work, the finite element method is employed which are frequently used for voltammetry but rarely for impedance spectroscopy. Specifically, this method is used for simulation of a complex reaction where a heterogeneous faradaic reaction is followed by a homogeneous chemical reaction. By tracing the current and its polarization resistance, I learn that their relationship can be explained in terms of rate constants of charge transfer and chemical change. An unexpected observation is that even though the resistance is increased by the rate of the following chemical reaction, the current can be increased due to the potential shift of the resistance made by the proceeding faradaic reaction. This report envisions a possibility of the FEM-based resistance simulation to be applied to understand a complex electrochemical reaction. Until now, resistance simulations are mostly based on equivalent circuits or complete mathematical equations and have limitations to find proper models. However, this method is based on the first-principles, and is expected to be complementary to the other simulation methods.

Sol-gel TiO₂/Carbon Paste Electrode Nanocomposites for Electrochemical-assisted Sensing of Fipronil Pesticide

Maulidiyah, Maulidiyah,Azis, Thamrin,Lindayani, Lindayani,Wibowo, Dwiprayogo,Salim, La Ode Agus,Aladin, Andi,Nurdin, Muhammad The Korean Electrochemical Society 2019 Journal of electrochemical science and technology Vol.10 No.4

The unique study of TiO₂ sol-gel modified carbon paste electrode (CPE) nanocomposites have been developed for electrochemical sensor detecting fipronil pesticide compound. We develop the easy synthesized TiO₂ via a sol-gel method and modified in CPE which applied electrochemical system as cyclic voltammetry (CV) because the concentration is proportional with current peaks. We discover the TiO₂ optimal mass used of 0.1 g which is compared with 0.7 g carbon and 0.3 mL paraffin. It has high-current anodic (Ip_a) of 1.13×10³ μA and high-current cathodic (Ip_c) -0.96×10³ μA in scan rate of 0.5 V/s. The limit of detection (LOD) of fipronil has been determined of 34.0×10^-5 μM in percent recovery of 0.8%. Its high-stability for lifetime TiO₂-CPE nanocomposites was expressed for 13 days which mean that can be used for detecting fipronil pesticide.