Xem 1-12 trên 12 kết quả Voltammetry
  • Voltammetry techniques measure current as a function of applied potential under conditions that promote polarization of a working electrode. Polarography: Invented by J. Heyrovsky (Nobel Prize 1959). Differs from voltammetry in that it employs a dropping mercury electrode (DME) to continuously renew the electrode surface. Amperometry: current proportional to analyte concentration is monitored at a fixed potential

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  • The cathodic reduction of nitrate and nitrite ions on a copper electrode in aqueous potassium chloride solutions was studied using cyclic voltammetry technique. The cyclic voltammograms showed that nitrate and nitrite ion reduction occurred in the 0.14 M KCl solution with peak potentials of -1.25 to -1.30 V and -1.20 to -1.25 V (Ag/AgCl) respectively.

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  • To help you further Chemistry references. Invite you to consult the document content "Chapter 7: Electroanalytical Techniques". The contents of the presentation materials: Fundamentals of electrolysis, electrogravimetric analysis, voltammetry. Hope this is useful references for you.

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  • Đồ án tốt nghiệp: Nghiên cứu hành vi điện hoá của vật liệu điện cực và dung môi trong nguồn điện Lithium trình bày về các phương pháp để nghiên cứu hành vi điện hoá của vật liệu điện cực và dung môi trong nguồn điện Lithium bao gồm phương pháp quét thế vòng CV(Cyclic voltammetry), phương pháp đo phổ tổng trở, phương pháp đo đường cong phóng điện.

     

     

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  • In this paper, nickel oxide thin films on the titanium substrate were prepared by the sol-gel dipcoating technique with the precursors NiSO4.7H2O and acetic acid. The obtained thin films have a good adhesion to the substrate. The electrochemical behaviors of the NiOxHy thin films were investigated in KOH 1 M solution by the voltammetry technique. The effect of addition of platinum, heating temperature and the dip coating number on the electrochemical behavior was also investigated. The thin films have high electrochemical properties at 270o C and at third dip coating.

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  • Chemical structure of -aminonaphthalene (ANa) allows to deal with its electrochemical polymerisation, analogously as for aniline. To determine the oxidation potentials of ANa, the polymerisation has been realised on Pt electrode using cyclic polarisation. It was found that in sulphuric acid 0.5 M the first oxidation starts at 620 mV/SCE with the peak potential at 760 mV, and the second oxidation at 890 mV/SCE with the peak potential at 1230 mV. The PANa film development decreases the current peaks meaning a reduction of polymerisation rate.

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  • Electrochemical systems—e.g., batteries, capacitors, and fuel cells—are an integral part of modern technology. Electrochemical techniques, especially potentiometry and voltammetry, are indispensable for state-of-the-art analysis, and also for fundamental studies of the properties of solution species and solid phases and materials. Last, but not least, electrochemical concepts for understanding charge transfer reactions entered the fields of biochemistry and biophysics.

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  • One of the subjects of Ni-MH batteries studies is justly the electrochemically active material for the positive electrode-hydroxide nickel. This hydroxide Ni(OH)2 has been prepared in laboratory by chemical sedimentation from NiCl2 and NaOH solutions. The obtained product has been examined using different techniques, such as X ray Diffraction (XRD), Scanning Electronic Microscope (SEM) and electrochemical polarisation (cyclic voltammetry CV). The obtained results of obtained Ni(OH)2 show -type crystal, with grains of about 15 µm.

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  • Polyaniline has been utilised as an additive of the LaNi5 based negative electrodes which are activated using cyclic voltammetry. With GPES programme, exchange current i0, polarisation resistance Rp were determined. Variation of these parameters, and also of the currents at E = - 0.8 V and E = -1.2 V and of the charges quantities of charging process Qn and of discharging process Qp, as a function of PANi weight percentage x (wt%), have been studied, in order to estimate the effect of the ratios x on the negative electrodes activation.

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  • The electrophoretic deposition (EPD) method was adopted for a fabrication of nanocomposite layers composed of ZnO particles covered by the polythiopene shell in a reduced state. This composite was prepared by oxidative polymerization of thiophene monomer with iron (III) chloride as a catalyst in the presence of ZnO particles. After polymerization, polythiophene in oxidized form was reduced by the extraction in methanol. Electrochemical properties of the obtained composite were measured by cyclic voltammetry and electrochemical impedance spectroscopy.

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  • For the first time, the detection of DNA sequences, related to HIV (found in AIDS patients), using Methylene Blue (MB) as the redox indicator was performed. The voltametric signals have been investigated on bared chitosan (CS) modified; probe immobilized (DNA single strand) and target-hybridized (DNA double strand) electrodes sequentially by means of Cyclic Voltammetry (CV) and Square Wave Voltammetry (SWV). The response of hybridization between the probe and perfectly complementary, double-base mismatch, single-base mismatch of analyzed targets were clearly identified.

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  • Bismuth film electrode (BiFE) of less environmentally concern was developed to determine blood lead by differential pulse - anodic stripping voltammetry (DP-ASV). The lead determination gained high precision (RSD < 4.5%, n = 2) and low detection limit (0.7 ppb), that were not worse than those on mercury film electrode (MFE). The acurracy of the lead dertermination (recovery 98 – 100.6%) was good agreement with GF-AAS determination (p > 0.05).

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