• 제목/요약/키워드: Electrocatalytic behavior

검색결과 21건 처리시간 0.021초

Physioelectrochemical Investigation of Electrocatalytic Oxidation of Saccharose on Conductive Polymer Modified Graphite Electrode

  • Naeemy, A.;Ehsani, A.;Jafarian, M.;Moradi, M.
    • Journal of Electrochemical Science and Technology
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    • 제6권3호
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    • pp.88-94
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    • 2015
  • In this study we investigated the electrocatalytic oxidation of saccharose on conductive polymer- Nickel oxide modified graphite electrodes based on the ability of anionic surfactants to form micelles in aqueous media. This NiO modified electrode showed higher electrocatalytic activity than Ni rode electrode in electrocatalytic oxidation of saccharose. The anodic peak currents show linear dependency with the square root of scan rate. This behavior is the characteristic of a diffusion controlled process. Under the CA regime the reaction followed a Cottrellian behavior and the diffusion coefficient of saccharose was found in agreement with the values obtained from CV measurements.

Effect of Thermal Treatment on the Electrocatalytic Activities and Surface Roughness of ITO Electrodes

  • Choi, Moon-Jeong;Jo, Kyung-Mi;Yang, Hae-Sik
    • Journal of Electrochemical Science and Technology
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    • 제3권1호
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    • pp.24-28
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    • 2012
  • The electrocatalytic activities and surface roughness of indium-tin-oxide (ITO) electrodes have been investigated after thermal treatment at 100, 150, or $200^{\circ}C$ for 30 min, 2 h, or 8 h. To check electrocatalytic activities, the electrochemical behavior of four electroactive species (p-hydroquinone, $Ru(NH_3){_6}^{3+}$, ferrocenemethanol, and $Fe(CN){_6}^{4-}$) has been measured. The electron transfer rate for p-hydroquinone oxidation and ferrocenemethanol oxidation increases with increasing the incubation temperature and the incubation period of time, but the rate for $Ru(NH_3){_6}^{3+}$ is similar irrespective of the incubation temperature and period because $Ru(NH_3){_6}^{3+}$ undergoes a fast outer-sphere reaction. Overall, the electrocatalytic activities of ITO electrodes increase with increasing the incubation temperature and period. The surface roughness of ITO electrodes increases with increasing the incubation temperature, and the thermal treatment generates many towering pillars as high as several tens of nanometer.

Observation of Electrocatalytic Amplification of Iridium Oxide (IrOx) Single Nanoparticle Collision on Copper Ultramicroelectrodes

  • Choi, Yong Soo;Jung, Seung Yeon;Joo, Jin Woo;Kwon, Seong Jung
    • Bulletin of the Korean Chemical Society
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    • 제35권8호
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    • pp.2519-2522
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    • 2014
  • Recently, the observation of the electrocatalytic behavior of individual nanoparticles (NPs) by electrochemical amplification method has been reported. For example, the Iridium oxide ($IrO_x$) NP collision on the Pt UME was observed via electrocatalytic water oxidation. However, the bare Pt UME had poor reproducibility for the observation of NP collision signal and required an inconvenient surface pre-treatment for the usage. In this manuscript, we has been investigated other metal electrode such as Cu UME for the reproducible data analysis and convenient use. The $IrO_x$ NP collision was successively observed on the bare Cu UME and the reproducibility in collision frequency was improved comparing with previous case using the $NaBH_4$ pre-treated Pt UME. Also, the adhesion coefficient between NP and the Cu UME was studied for better understanding of the single NP collision system.

산화 이리듐의 물의 산화반응에 대한 버블 과전압 현상과 촉매 특성 연구 (Study on Electrocatalytic Water Oxidation Reaction by Iridium Oxide and Its Bubble Overpotential Effect)

  • 김정중;최용수;권성중
    • 전기화학회지
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    • 제16권2호
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    • pp.70-73
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    • 2013
  • 산화 이리듐은 물의 산화반응에 대해 좋은 전기촉매 물질로서 많은 연구가 이루어 지고 있다. 최근 전기화학적 증폭방법을 이용하여 산화 이리듐 나노입자의 개별적인 촉매특성을 연구한 결과를 보면 촉매반응에 의한 전류가 지속적으로 유지되지 않고 시간에 따라 감소하는 결과가 얻어 졌다. 이러한 촉매특성의 사라짐에 대한 원인을 규명하고자 사이즈가 큰 이리듐전극을 산화시킨 산화이리듐 전극에서 물의 산화반응을 진행시켰다. 그 결과 나노입자에서와 유사하게 전류가 감소하는 현상이 관찰되었다. 큰 전극에서의 실험에서는 발생하는 산소방울을 관찰 할 수 있었는데 산소방울의 발생 주기가 전류의 증감주기와 일치하는 것으로 보아 전류의 감소는 산소방울에 의한 버블 과전압 때문으로 생각된다.

Electro-Catalytic Behavior of an Antiarrhythmic Drug, Procainamide and its Electro-Analytical Applications

  • Abbar, Jyothi C.;Meti, Manjunath D.;Nandibewoor, Sharanappa T.
    • Journal of Electrochemical Science and Technology
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    • 제9권4호
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    • pp.292-300
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    • 2018
  • The electrocatalytic oxidative behavior of an antiarrhythmic drug, procainamide hydrochloride (PAH) at the gold electrode surface has been examined using different voltammetric methods like cyclic, linear-sweep and differential pulse voltammetry. Voltammograms obtained in this study reveal that the electrode exhibit excellent electrocatalytic activity towards oxidation of the drug. The parameters that can affect the peak current at different pH, scan rate and concentration were evaluated. The number of electrons transferred was calculated. The current displayed a wide linear response ranging from 0.5 to $30.0{\mu}M$ with a limit of detection of 56.4 nM. The impact of potential interfering agents was also studied. The electrode displayed wide advantages such as simple sample preparation, appreciable repeatability, reproducibility and also high sensitivity. Furthermore, the feasibility of the proposed method was successfully demonstrated by determining PAH in the spiked human biological sample.

A Kinetic Investigation of Ethanol Oxidation on a Nickel Oxyhydroxide Electrode

  • Danaee, I.;Jafarian, M.;Sharafi, M.;Gobal, F.
    • Journal of Electrochemical Science and Technology
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    • 제3권1호
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    • pp.50-56
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    • 2012
  • Nickel modified NiOOH electrodes were used for the electrocatalytic oxidation of ethanol in alkaline solutions where the methods of cyclic voltammetry (CV) and chronoamperometry (CA) were employed. In CV studies, in the presence of ethanol, an increase in the current for the oxidation of nickel hydroxide is followed by a decrease in the corresponding cathodic current. This suggests that the oxidation of ethanol is being catalysed through mediated electron transfer across the nickel hydroxide layer comprising of nickel ions of various valence states. Under the CA regime the reaction followed a Cottrellian behavior and the diffusion coefficient of ethanol was found to be $1{\times}10^7cm^2s^{-1}$.

The Preparation of Polyaniline Electrode Modified by Copper Phthalocyanine on Supporting Carbon Paper

  • Park, Jin-Seok;Kim, Jeong-Soo
    • Macromolecular Research
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    • 제9권3호
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    • pp.179-183
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    • 2001
  • Cathode materials for the polymer electrolyte membrane fuel cell was prepared by electropoly-merization of aniline at carbon paper in the presence of copper tetrasulfonato-phthalocyanine (CuTsPc) and their electrocatalytic behavior was studied. The amount of polyaniline and CuTsPc in the carbon paper was determined by UV spectroscopy of residual solution in electrochemical cell. The redox process of the prepared electrodes was investigated with cyclic voltammetry. The highest reversible current density was observed at the electrode that contains 27.6 wt% of polyaniline and 19.7 wt% of CuTsPc. The morphology of composite electrode from SEM showed the presence of large cluster of polyaniline with CuTsPc, which should be more finely interpenetrated into macropores of carbon for the better electrocatalytic activity.

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SAMs of 2-Aminoethanethiol Modified with 3,4-Dihydroxyphenylalanine for the Electrocatalytic Oxidation of NADH on Gold Electrodes

  • Cha, Seong-Keuck
    • Bulletin of the Korean Chemical Society
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    • 제25권6호
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    • pp.786-790
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    • 2004
  • 2-Aminoethanethiol (aet) has been used to make self-assembled monolayer (SAMs) on gold electrodes, which are subsequently modified with 3,4-dihydroxy phenylalanine (dpa). Such modified electrodes having various types of Au/aet-dpa were employed in the electrocatalytic oxidation of NADH. The purpose of this study to characterize the responses of such modified electrodes in terms of the immobilization procedure, pH of the solution and applied potential. The reaction of the surface immobilized dpa with NADH was studied using the rotating disk electrode technique and a value of $2.2{\times}10^4M^{-1}s^{-1}$ was obtained for the second-order rate constant in 0.1 M Tris/$NO_3^-$buffer (pH=8.0). The hydration behavior of the films was characterized by quartz crystal microbalance. When used as a NADH sensor, the Au/aet-dpa electrode exhibited good sensitivity and an excellent correlation (r ${\geq}$ 0.99) for NADH concentration which extended to $3.8{\times}10^{-3}$ M.