• Title, Summary, Keyword: catalytic activity of electrode

Search Result 87, Processing Time 0.053 seconds

Electro-Catalytic Oxidation of Amoxicillin by Carbon Ceramic Electrode Modified with Copper Iodide

  • Karim-Nezhad, Ghasem;Pashazadeh, Ali;Pashazadeh, Sara
    • Journal of the Korean Chemical Society
    • /
    • v.57 no.3
    • /
    • pp.322-328
    • /
    • 2013
  • Copper iodide was employed as a modifier for preparation of a new carbon ceramic electrode. For the first time, the catalytic oxidation of amoxicillin (AMX) was demonstrated by cyclic voltammetry, chronoamperometry and amperometry methods at the surface of this modified carbon ceramic electrode. The copper iodide modified sol-gel derived carbon ceramic (CIM-SGD-CC) electrode has very high catalytic ability for electrooxidation of amoxicillin. The catalytic oxidation peak current was linearly dependent on the amoxicillin concentration and the linearity range obtained was 100 to 1000 ${\mu}mol\;L^{-1}$ with a detection limit of 0.53 ${\mu}mol\;L^{-1}$. The diffusion coefficient ($D=(1.67{\pm}0.102){\times}10^{-3}\;cm^2\;s^{-1}$), and the kinetic parameter such as the electron transfer coefficient (${\alpha}$) and exchange current density ($j_0$) for the modified electrode were calculated. The advantages of the modified CCE are its good stability and reproducibility of surface renewal by simple polishing, excellent catalytic activity and simplicity of preparation.

Comparison of Catalytic Activity for Methanol Electrooxidation Between Pt/PPy/CNT and Pt/C

  • Lee, C.G.;Baek, J.S.;Seo, D.J.;Park, J.H.;Chun, K.Y.
    • Journal of the Korean Electrochemical Society
    • /
    • v.13 no.4
    • /
    • pp.240-245
    • /
    • 2010
  • This work explored the catalytic effect of Pt in multi-wall carbon nanotube and poly-pyrrole conductive polymer electrocatalysts (Pt/PPy/MWCNT). A home-made Pt/PPy/MWCNT catalyst was first evaluated by comparing its electrochemical active surface area (ESA) with E-Tek commercial catalysts by cyclic voltammetry in $H_2SO_4$ solution. Then, the methanol oxidation currents of Pt/PPy/MWCNT and the hydrogen peaks in $H_2SO_4$ solution were serially measured with microporous electrode. This provided the current density of methanol oxidation based on the ESA, allowing a quantitative comparison of catalytic activity. The current densities were also measured for Pt/C catalysts of E-Tek and Tanaka Precious Metal Co. The current densities for the different catalysts were similar, implying that catalytic activity depended directly on the ESA rather than charge transfer or electronic conductivity.

PEDOT Polymer Film Based Counter Electrodes for Pt-free Dye-Sensitized Solar Cells

  • Kwon, Jeong;Park, Jong Hyeok
    • Journal of Electrochemical Science and Technology
    • /
    • v.4 no.3
    • /
    • pp.89-92
    • /
    • 2013
  • Poly (3,4-ethylenedioxythiophene) (PEDOT) polymers with different electric conductivities were synthesized directly on a FTO substrate via a chemical polymerization method and applied as a platinum (Pt)-free counter electrode for dye-sensitized solar cells (DSSCs). The catalytic properties of the PEDOT as a function of electrical conductivity were studied using cyclic voltammograms, J-V measurements and impedance spectroscopy. The PEDOT counter electrode with around 340 S/cm conductivity exhibited the best performance as a counter electrode for tri-iodide reduction. The ability to modulate catalytic activity of PEDOT with changes in conductivity shows one of promising routes for developing new counter electrode of Pt-free DSSCs.

Electrocatalysis of Oxygen Reduction by Cu-containing Polymer Films on Glassy Carbon Electrodes

  • Kim, Jong-Won;Gewirth, Andrew A.
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.8
    • /
    • pp.1322-1328
    • /
    • 2007
  • The catalytic activity of poly[(2,2'-bipyridine)copper(II)-μ4-oxalato] coated on a glassy carbon electrode (GCE) for O2 electroreduction is examined using cyclic voltammetry and rotating disk electrode techniques. The cyclic voltammograms show that O2 is electroreduced on pBpCuOx-coated GCE surfaces at a peak potential of ? 0.25 V in pH 4.7 acetate buffer media. The electroreduction of O2 on pBpCuOx-coated GCE occurs at 450 mV more positive potential than that found at a bare GCE. The catalytic activity originates from Cu(II) coordinated by bipyridine in the complexes and the polymer type Cu-complex films exhibit an enhanced stability compared to monomeric Cu-complexes during the O2 electroreduction. The rotating disk electrode measurements reveal that the electroreduction of O2 on pBpCuOx-coated GCE is a four-electron process. Kinetic parameters for O2 reduction on pBpCuOx-coated GCE are obtained from rotating disk experiments and compared with those on bare glassy carbon electrode surfaces.

A study on the characteristics of inner cell pressure for sealed type Ni-MH rechargeable battery using Zr-based hydrogen storage alloy as anode (Zr-based 수소저장합금을 음극으로 사용한 밀패형 Ni-MH 2차전지의 내압특성에 관한 연구)

  • Kim, Dong-Myung;Lee, Ho;Jang, Kuk-Jin;Lee, Jai-Young
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.8 no.2
    • /
    • pp.79-90
    • /
    • 1997
  • Extensive work has been done on investigating the inner cell pressure characteristics of sealed type Ni-MH battery in which Zr-Ti-Mn-V-Ni alloy is used as anode. The inner cell pressure of this type Ni-MH battery much more increases with the charge/discharge cycling than that of the other type Ni-MH battery where commercialized $AB_5$ type alloy is used as anode. The increase of inner cell pressure in the sealed type Ni/MH battery using Zr-Ti-Mn-V-Ni alloy system is mainly due to the accumulation of oxygen gas during charge/discharge cycling. The accumulation of oxygen gas arises mainly due to the low rate of oxygen recombination on the MH electrode surface during charge/discharge cycling. The difference of oxygen recombination rate between $AB_5$ type electrode and Zr-Ti-Mn-V-Ni electrode is caused by the difference of electrode reaction surface area resulting from different particle size after their activation and the difference of surface catalytic activity for oxygen recombination reaction, respectively. After EIS analysis, it is identified that the surface catalytic activity affects much more dominantly on the oxygen recombination reaction than the reaction surface area does. In order to suppress the inner cell pressure of Ni-MH battery where Zr-Ti-Mn-V-Ni is used as anode, it is suggested that the surface catalytic activity for oxygen recombination should be improved.

  • PDF

Nonenzymatic Sensor Based on a Carbon Fiber Electrode Modified with Boron-Doped Diamond for Detection of Glucose (보론 도핑 다이아몬드로 표면처리된 탄소섬유 기반의 글루코스 검출용 비효소적 바이오센서)

  • Song, Min-Jung
    • Korean Chemical Engineering Research
    • /
    • v.57 no.5
    • /
    • pp.606-610
    • /
    • 2019
  • In this study, we demonstrated that the nonenzymatic glucose sensor based on the flexible carbon fiber bundle electrode with BDD nanocomposites (CF-BDD electrode). As a nano seeding method for the deposition of BDD on flexible carbon fiber, electrostatic self-assembly technique was employed. Surface morphology of BDD coated carbon fiber electrode was observed by scanning electron microscopy. And the electrochemical characteristics were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry. This CF-BDD electrode exhibited a large surface area, a direct electron transfer between the redox species and the electrode surface and a high catalytic activity, resulting in a wider linear range (3.75~50 mM), a faster response time (within 3 s) and a higher sensitivity (388.8 nA/mM) in comparison to a bare CF electrode. As a durable and flexible electrochemical sensing electrode, this brand new CF-BDD scheme has promising advantages on various electrochemical and wearable sensor applications.

Preperation of catalyst having high activity on oxygen reduction (저온형 연료전지용 산소의 고활성 환원 촉매 제조)

  • 김영우;김형진;이주성
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
    • /
    • /
    • pp.39-40
    • /
    • 1992
  • This paper dealt with the manufacturing of binary alloy catalyst and showed simple electrochemical method for determing catalytic activity of oxygen reduction in acid or alkaline electrolyte. The catalyst was prepared by impregnating transition metal salts on platinum or silver particles adsorbed before on carbon paper substrate. The electrochemical characteristics of the catalysts was investigated with carbon paper electrode or PTFE-boned porous electrode and then cathodic current densities and tafel slopes were compared. As a result, of all binary catalysts utilized in this work, Pt-Fe, Pt-Mo showed better oxygen reduction activity than pure platinum catalyst in acid electrolyte and Ag-Fe, Ag-Pt, and Ag-Ni-Bi-Ti catalyst did than pure silver catalyst in alkaline electrolyte. The current density of Pt-Fe electrode in acid electrolyte was one and half times higher than that of Pt electrode(~500mA/$\textrm{cm}^2$ at 0.7VvsNHE).

  • PDF

Catalytic Effects of Heteroatom-doped Graphene Nanosheets on the Performance of Li-O2 Batteries

  • Bae, Youngjoon;Lim, Hee-Dae;Yun, Young Soo;Kang, Kisuk
    • Journal of Electrochemical Science and Technology
    • /
    • v.5 no.2
    • /
    • pp.49-52
    • /
    • 2014
  • Graphene nanosheets (GNS), nitrogen-doped graphene nanosheets (N-GNS), and sulfur-doped graphene nanosheets (S-GNS) were successfully synthesized, and their catalytic effects on the oxygen reduction reaction (ORR) in $Li-O_2$ batteries were compared. The S-GNS electrode exhibited the highest ORR catalytic activity, resulting in enhanced discharge capacity and power capability. We attributed the enhanced ORR catalytic activity to the increased defect sites on graphene.

Improvement in Catalytic Activity of Ag Catalyst via Simple Mixing with Carbon

  • Choun, Myounghoon;Baek, Ji Yun;Eom, Taehyoung
    • KEPCO Journal on Electric Power and Energy
    • /
    • v.5 no.4
    • /
    • pp.331-335
    • /
    • 2019
  • In this study we investigate catalytic activity and selectivity of mixture of Ag and ketjenblack according to their ratios by product analysis and electrochemical experiments, such as cyclic voltammetry, linear sweep voltammetry and chronoamperometry. We reveal that catalytic activity toward CO2 reduction to CO is improved by simple mixing Ag nanoparticle and ketjenblack because addition of ketjenblack suppresses aggregation of Ag nanoparticles and brings increase in electrochemical active surface area. However, excess amount of ketjenblack rather inhibit the CO2 reduction to CO. These observations provide clues to develop highly active Ag catalyst or electrode toward electrochemical reduction of CO2.