• 제목/요약/키워드: Cyclic Voltammetry (CV)

검색결과 278건 처리시간 0.032초

순환 전압전류법의 기초 (Fundamentals of cyclic voltammetry)

  • 신가윤;엄완식;유동재;강석우;김은비;김현우
    • 센서학회지
    • /
    • 제30권6호
    • /
    • pp.384-387
    • /
    • 2021
  • Cyclic voltammetry (CV) is a powerful electrochemical measurement technique that can determine redoxable substances in a solution. The advantage of CV is that we can observe redox behavior over a wide potential range in a short time. Because of its practicality and versatility, CV is used not only in electrochemistry but also in various fields of chemistry, such as inorganic chemistry, organic chemistry, and biochemistry. As technology advances and the popularity of CV grows, the need for trained electrochemists also increases. However, most students do not receive formal training in these technologies as part of their curriculum. There are few concise and accessible resources for learning CV. Therefore, this manuscript provides a brief introduction to cyclic voltammetry to aid readers in collecting and interpreting useful data from cyclic voltammograms.

자가조립 단층 전극에 대한 순환전위법의 특성해석 (Characteristic Analysis of Cyclic Voltammetry on a Self-Assembled Mono-layer Electrode)

  • 조하나;윤도영
    • 전기화학회지
    • /
    • 제16권4호
    • /
    • pp.217-224
    • /
    • 2013
  • 본 연구에서는 금 나노입자로 전착된 전극위에 3-MPA로 개질된 자가조립 단층 전극의 순환전위법의 특성을 조사하였다. 또한 전극 주변에서 전자와 이온의 이동현상을 해석하였다. 반무한 확산모델을 채택하여, 물질전달 지배계에 대하여 지배방정식과 경계조건을 유도하였다. 자가조립단층 전극에 대한 순환전위법의 수치해를 구하기 위하여, 양함수 유한차분법을 적용하여 MATLAB 프로그램을 작성하여 해를 구현하였다. 자가조립으로 개질된 전극에 대한 본 CV 용 프로그램은 3-MPA으로 개질된 금 나노입자 SAM 전극의 순환전위법 실험결과를 잘 설명하고 있음을 확인할 수 있었다.

Adsorptive Behavior of Catechol Violet and Its Thorium Complex on Mercury Electrode in Aqueous Media

  • Rabia Mostafa K. M.
    • 전기화학회지
    • /
    • 제7권1호
    • /
    • pp.9-15
    • /
    • 2004
  • Cyclic voltammetry and chronocoulometry have been used for characterization of catechol violet (CV) at the hanging mercury drop electrode in acetic acid-sodium acetate buffer solution. At pH 2.94 a nearly symmetric cyclic voltammetric wave due to an irreversible weak adsorption of CV on mercury was obtained at concentration of $0.53{\mu}mol\;dm ^{-3}$. Under these conditions, CV adsorbes in a monolayer. Upon increasing the concentration, the symmetry of the wave decreases; it can be attributed to a mixed diffusion adsorption process. The amount of the adsorbed catechol violet on the HMDE expressed as surface concentration as well as the surface areaf occupied by one molecule$(\sigma)$ were calculated. It was found that the values obtained for f and o utilizing cyclic voltammetric and chrono-coulometry are almost identical. A 1:1 and 1:2 Th (IV)-CV complexes are formed on addition of thorium (IV) to catechol violet. These complexes are adsorbed and reduced on the HMDE at more negative potentials than the peak potential of free CV, Using the square-wave (SW) technique, the adsorptive cathodic stripping voltammetry, ACSV, of these complexes was studied. It was found that the SW-ACSV of Th(IV)-CV can be applied to the determination of thorium at the nanomole level. Optimum conditions and the analytical method of determination were presented and discussed.

$KNO_3$$HNO_3$ 전해액이 Cu에 미치는 영향 (Effect of copper surface to $HNO_3$ and $KNO_3$ electrolyte)

  • 서용진;한상준;박성우;이영균;이성일
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
    • /
    • pp.486-486
    • /
    • 2009
  • In this paper, the current-voltage (I-V) curves, such as linear sweep voltammetry (LSV) and cyclic voltammetry (CV), were employed to evaluate the effect of electrolyte concentration on the electrochemical reaction trend. From the I-V curve, the electrochemical states of active, passive, transient and trans-passive could be characterized. And then, we investigated that how this chemical affect the process of voltage-induced material removal in electrochemical mechanical polishing (ECMP) of Copper. The scanning electron microscopy (SEM) and energy dispersive spectroscopy EDS) analyses were used to observe the surface profile. Finally, we monitored the oxidation and reduction process of the Cu surface by the repetition of anodic and cathodic potential from cyclic voltammetry (CV) method in acid- and alkali-based electrolyte. From these analyses, it was important to understand the electrochemical mechanisms of the ECMP technology.

  • PDF

Applications of Voltammetry in Lithium Ion Battery Research

  • Kim, Taewhan;Choi, Woosung;Shin, Heon-Cheol;Choi, Jae-Young;Kim, Ji Man;Park, Min-Sik;Yoon, Won-Sub
    • Journal of Electrochemical Science and Technology
    • /
    • 제11권1호
    • /
    • pp.14-25
    • /
    • 2020
  • Li ion battery (LIB) is one of the most remarkable energy storage devices currently available in various applications. With a growing demand for high-performance batteries, the role of electrochemical analysis for batteries, especially, electrode reactions are becoming very important and crucial. Among various analytical methods, cyclic voltammetry (CV) is very versatile and widely used in many fields of electrochemistry. Through CV, it is possible to know electrochemical factors affecting the reaction voltage and reversibility, and furthermore, quantitative analysis on Li+ diffusivity as well as intercalation and capacitive reactions, and also anionic redox reaction. However, the explanation or interpretation of the results of CV is often deficient or controversial. In this mini-review, we briefly introduce the principle of cyclic voltammetry and its applications in LIB to bring a better understanding of the electrochemical reaction mechanisms involved in LIB.

Voltammetric Assay of Silver Ions in Frog's Tissue

  • Ly, Suw-Young;Lee, Jin-Hui;Lee, Chang-Hyun
    • 한국응용과학기술학회지
    • /
    • 제30권1호
    • /
    • pp.139-145
    • /
    • 2013
  • The electrochemical analysis of silver ion was performed using cyclic voltammetry (CV) and square-wave (SW) stripping voltammetry, and electrode cell systems were fabricated with graphite pencil electrode (GE) of working, reference and counter electrodes. Also electrolyte was the use of sea water as electrolyte solutions instead of ionic controlled solutions. The optimum analytical conditions for the cyclic and stripping parameters were determined using GE. The results approached the microgram working ranges of SW(ug/L) and CV(ug/L) Ag, and the optimum conditions were applied to frog's tissue and the food samples.

고분자 전해질막 연료전지의 활성화를 위한 CV 활성화법 (Application of CV Cycling to the Activation of the Polymer Electrolyte Membrane Fuel Cell)

  • 조기윤;정호영
    • 공업화학
    • /
    • 제23권5호
    • /
    • pp.445-449
    • /
    • 2012
  • 고분자 전해질막 연료전지의 대량 생산을 위하여 막-전극 접합체(MEA) 활성화 방법의 개발이 중요한 현안이다. 현재 개발된 MEA활성화 방법은 시간이 많이 소요됨으로 인해 수소의 사용량 또한 증가하여 연료전지의 상용화에 큰 걸림돌이 되고 있다. 통상적인 활성화 방법은 활성화 원리를 주로 전해질 수화 관점에서 이해하였다. 반면, 본 논문에서 제안된 순환전압전류(cyclic voltammetry, CV) 활성화 방법은 전해질 및 촉매적 관점에서 별도로 분리하여 이해하였다. 따라서 전해질 관점에서는 상대 습도 100%인 가습된 질소를 공급하여 전극 및 막의 전해질을 수화시키는 과정으로 구성되고, 촉매적 관점에서는 CV 사이클을 수행하여 백금 촉매에 흡착되어 있는 불필요한 오염물질, 또는 산화피막을 제거하는 과정으로 수행된다. CV 활성화법은 2.5 h 내에 활성화가 종료되어 활성화 시간을 크게 단축시킬 수 있을 뿐만 아니라, 수소 사용량도 기존 활성화 방법에 비하여 1/4 이하로 감소시킬 수 있어서 효과적인 연료전지 활성화 방법으로 제안하고자 한다.

Electrochemical Impedance Spectroscopy and Cyclic Voltammetry Methods for Monitoring SmCl3 Concentration in Molten Eutectic LiCl-KCl

  • Shaltry, Michael R.;Allahar, Kerry N.;Butt, Darryl P.;Simpson, Michael F.;Phongikaroon, Supathorn
    • 방사성폐기물학회지
    • /
    • 제18권1호
    • /
    • pp.1-18
    • /
    • 2020
  • Molten salt solutions consisting of eutectic LiCl-KCl and concentrations of samarium chloride (0.5 to 3.0 wt%) at 500℃ were analyzed using both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The CV technique gave the average diffusion coefficient for Sm3+ over the concentration range. Equipped with Sm3+ diffusion coefficient, the Randles-Sevcik equation predicted Sm3+ concentration values that agree with the given experimental values. From CV measurements; the anodic, cathodic, and half-peak potentials were identified and subsequently used as a parameter to acquire EIS spectra. A six-element Voigt model was used to model the EIS data in terms of resistance-time constant pairs. The lowest resistances were observed at the half-peak potential with the associated resistance-time constant pairs characterizing the reversible reaction between Sm3+ and Sm2+. By extrapolation, the Voigt model estimated the polarization resistance and established a polarization resistance-concentration relationship.

Trapezoidal Cyclic Voltammetry as a Baseline for Determining Reverse Peak Current from Cyclic Voltammograms

  • Carla B. Emiliano;Chrystian de O. Bellin;Mauro C. Lopes
    • Journal of Electrochemical Science and Technology
    • /
    • 제15권3호
    • /
    • pp.405-413
    • /
    • 2024
  • Several techniques for determining the reverse peak current from a cyclic voltammogram (CV) for a reversible system are described in the literature: CV itself as a baseline with long switching potential (Eλ) that serves as a baseline for other CVs, Nicholson equation that uses CV parameters to calculation reverse peak current and linear extrapolation of the current obtained at the switching potential. All methods either present experimental difficulties or large errors in the peak current determination. The paper demonstrates, both theoretically and experimentally, that trapezoidal cyclic voltammetry (TCV) can be used as a baseline to determine anodic peak current (iap) with high accuracy and with a switching potential shorter than that used by CV, as long as Eλ is at least 130 mV away from the cathodic peak. Beyond this value of switching potential the electroactive specie is completely depleted from the electrode surface. Using TCV with Eλ = 0.34 V and a switching time (tλ) of 240 s as a baseline, the determination of the reverse peak current presents a deviation from the expected value of less than 1% for most of the CVs studied (except cases when Eλ is close to the direct potential peak). This result presents better accuracy than the Nicholson equation and the linear extrapolation of the current measured at the switching potential, in addition to presenting a smaller error than that obtained in the acquisition of the experimental current. Furthermore, determining the reverse peak current by extrapolating the linear fit of iap vs. ${\sqrt[1/]{t_{\lambda}}}$ to infinite time gave a reasonable approximation to the expected value. Experiments with aqueous potassium hexacyanoferrate (II) and ferrocene in acetonitrile confirmed the theoretical predictions.

$HNO_3$ 전해액이 Cu 표면에 미치는 영향 (Effect of copper surface to $HNO_3$ electrolyte)

  • 박성우;한상준;이영균;이우선;서용진
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
    • /
    • pp.123-123
    • /
    • 2008
  • 본 논문에서는 Cu의 ECMP 적용을 위해 $HNO_3$ 전해액의 active, passive, transient, trans-passive 영역을 I-V 특성 곡선을 통해 알아보았고, LSV (Linear sweep voltammetry)와 CV (Cyclic voltammetry)법을 통하여 전기화학적 특성을 비교 분석하였다.

  • PDF