• Title/Summary/Keyword: electrochemical behaviors

Search Result 281, Processing Time 0.032 seconds

Electrochemical Behaviors of Activated Carbons Prepared from Polymeric Precursor

  • Park, Soo-Jin;Lee, Eun-Jung;Kim, Byung-Joo;Lee, Young-Seak
    • Carbon letters
    • /
    • v.8 no.2
    • /
    • pp.134-136
    • /
    • 2007
  • In this work, activated carbons (ACs) were prepared from polystyrene-based cation-exchangeable resin (PSI) by a chemical activation with KOH as an activating agent. The surface morphologies were observed by using SEM, and the textural properties were investigated by using nitrogen adsorption at 77 K. From the experimental results, it was found that the well-developed micro- and mesopores were produced by a chemical activation, and the textural properties including specific surface areas and pore volumes were greatly enhanced. The electrochemical behaviors of the ACs showed similar phenomena with that of textural properties. These results indicated that KOH activation played an important role in the changes of surface, and pore structures, resulting in enhancing the electrochemical properties of the ACs prepared in present work.

Examination on Electrochemical Behaviors of Niobium Chloride in Molten LiCl-KCl by Cyclic Voltammetry

  • Jeong, Gwan Yoon;Park, Jaeyeong
    • Proceedings of the Korean Radioactive Waste Society Conference
    • /
    • 2018.11a
    • /
    • pp.299-300
    • /
    • 2018
  • Electrochemical behaviors of Nb ion in the $LiCl-KCl-NbCl_5$ molten salt were examined. Cyclic voltammograms with different scan rates and scan range at $450^{\circ}C$ showed possible electrochemical redox reactions which were identified by comparison to the literature data. Peak potentials for each redox reaction were consistent with the literature, but some redox reactions were not clearly defined due to the formation of subchloride compound in chloride salt. The electrochemical behaviors of Nb ion related to the subchloride formation as well as Nb metal deposition will be investigated for the future work.

  • PDF

Cryogenic fracture behaviors and polarization characteristics according to sensitizing heat treatment on structural material of the nuclear fusion reactor (핵 융합로 구조재료의 예민화 열처리에 따른 극저온 파괴거동 및 분극특성)

  • Kwon, Il-Hyun;Chung, Se-Hi
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.22 no.2
    • /
    • pp.311-320
    • /
    • 1998
  • The cryogenic fracture behaviors of austenitic stainless steel HN2 developed for nuclear fusion reactor were evaluated quantitatively by using the small punch(SP) test. The electrochemical polarization test was applied to study thermal aging degradation of HN2 steel. The X-ray diffraction(XRD) analysis was conducted to detect carbides and nitrides precipitated on the grain boundary of the heat treated HN2 steel. The mechanical properties of the HN2 steel significantly decreased with increasing time and temperature of heat treatment or with decreasing testing temperature. The integrated charge(Q) obtained from electrochemical polarization test showed a good correlation with the SP energy(ESP) obtained by means of SP tests. From the results observed in the x-ray diffraction and anodic polarization curve, it was known that the material the grain boundary. Combining SP test and electrochemical polarization test, it could be useful tools to non-destructively evaluate the cryogenic fracture behaviors and the aging degradation for cryogenic structural material.

Electrochemical behaviors of Indium

  • Chung, Yong-Hwa;Lee, Chi-Woo
    • Journal of Electrochemical Science and Technology
    • /
    • v.3 no.1
    • /
    • pp.1-13
    • /
    • 2012
  • Many researchers focus on indium contained semiconductors and alloy compounds for their various applications. Electrochemists want to obtain indium contained compounds simply via one-step electrodeposition. First of all, electrochemistry of constituent elements must be understood in order to develop the best condition for the electrodeposition of indium contained compounds. We will review the electrochemistry of indium. Equilibria between indium metal and indium ions and the standard electrode potentials of the equilibria will be reviewed. The electrochemical reactions of indium species are affected by surrounding conditions. Thus dependences of electrochemical behaviors of indium metal and indium ions on various parameters will be reviewed.

Effect of crystallinity on the electrochemical properties of carbon black electrodes

  • Yoo, Hye-Min;Heo, Gun-Young;Park, Soo-Jin
    • Carbon letters
    • /
    • v.12 no.4
    • /
    • pp.252-255
    • /
    • 2011
  • Carbon-based electric double-layer capacitors are being evaluated as potential energy-storage devices in an expanding number of applications. In this study, samples of carbon black (CB) treated at different temperatures ranging from $650^{\circ}C$ to $1100^{\circ}C$ were used as electrodes to improve the efficiency of a capacitor. The surface properties of the heat-treated CB samples were characterized by X-ray photoelectron spectroscopy and X-ray diffraction. The effect of the heat-treatment temperature on the electrochemical behaviors was investigated by cyclic voltammetry and in galvanostatic charge-discharge experiments. The experimental results showed that the crystallinity of the CBs increased as the heat-treatment temperature increased. In addition, the specific capacitance of the CBs was found to increase with the increase in the heat-treatment temperature. The maximum specific capacitance was 165 $F{\cdot}g-1$ for the CB sample treated at $1000^{\circ}C$.

Electrochemical Behaviors of 4-(2-thiazolylazo)-resorcinol in Acetonitrile

  • Bae, Zun-Ung;Lee, Heung-Lark;Seo, Moo-Lyung
    • Bulletin of the Korean Chemical Society
    • /
    • v.10 no.3
    • /
    • pp.258-261
    • /
    • 1989
  • The electrochemical behaviors of 4-(2)-thiazolylazo)-resorcinol (TAR) in acetonitrile solution was studied by DC polarography, cyclic voltammetry, controlled-potential coulometry and UV-Vis spectroscopy. The electrochemical reduction of TAR occurs in four-one electron reduction steps in acetonitrile solution. The products of the first and the third electron transfer are speculated to be a relatively stable anion radical. The second electron transfer to the dianion is followed by a chemical reaction producing a protonated species. The product of the fourth electron transfer also produces the corresponding amine compounds with a following reaction. Also every reduction wave was diffusion controlled. The first reduction wave is considerably reversible and the other waves are less reversible.