Kinetic study of redox reaction of Ce4+ ions with hypophosphite by means of vibrating platinum electrode

1977 ◽  
Vol 42 (8) ◽  
pp. 2332-2342
Author(s):  
Ľ. Treindl ◽  
J. Hatala
Keyword(s):  
Kinetic Study ◽  
Redox Reaction ◽  
Platinum Electrode

Kinetic study and characterization of a platinum electrode/sensitive membrane for malachite green detection

Sensor Review ◽  
2018 ◽  
Vol 38 (3) ◽  
pp. 335-344 ◽  
Author(s):  
Ilhem Ghodbane ◽  
Rochdi Kherrrat ◽  
Saida Zougar ◽  
Rim Lamari ◽  
Redouane Haddadji ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Detection Limit ◽  
Kinetic Study ◽  
Linear Relationship ◽  
Correlation Coefficient ◽  
Malachite Green ◽  
Platinum Electrode ◽  
Electrochemical Impedance ◽  
Polymeric Membrane ◽  
Content Type

PurposeThe purpose of this work is to explore electrical properties of an electrochemical sensor designed for the detection of malachite green (MG) present in an aqueous solution.Design/methodology/approachThe present sensor consists in the spatial coupling of a polymeric membrane and an ion-sensitive electrode (platinum electrode). The preparation of the polymeric membrane involves the incorporation of an ionophore (D2HPA), a polymer (polyvinylchloride [PVC]) and a plasticizer (dioctyl phthalate [DOP]). Several techniques have been used to characterize this sensor: the cyclic voltammetry, the electrochemical impedance spectroscopy and the optical microscopy. The sensibility, the selectivity and the kinetic study of a modified platinum electrode have been evaluated by cyclic voltammetry.FindingsThe obtained results reveal the possibility of a linear relationship between the current of reduction peaks and MG concentration. A linear response was obtained in a wide-concentration range that stretches from 10−5to 10−13mol L−1, with a good correlation coefficient (0.976) and a good detection limit of 5.74 × 10−14mol L−1(a signal-to-noise ratio of 3). In addition, the voltammetric response of modified electrode can be enhanced by adding a layer of Nafion membrane. Under this optimal condition, a linear relationship was obtained, with a correlation coefficient of 0.986 and a detection limit of 1.92 × 10−18mol L−1.Originality/valueIn the present research, a convenient, inexpensive and reproducible method for the detection of MG was developed. The developed sensor is capable of competing against the conventional techniques in terms of speed, stability and economy.

Kinetic study of redox reaction of U(IV) with ferricyanide ions

1972 ◽  
Vol 37 (3) ◽  
pp. 762-767 ◽  
Author(s):  
Ľ. Adamčíková ◽  
Ľ. Treindl
Keyword(s):  
Kinetic Study ◽  
Redox Reaction

Kinetics of oxidation of α-ketoglutaric acid with Ce(IV) ions in relation to Belousov-Zhabotinskii reaction

1982 ◽  
Vol 47 (11) ◽  
pp. 2831-2837 ◽  
Author(s):  
Ľudovít Treindl ◽  
Vasil Dorovský
Keyword(s):  
Redox Reaction ◽  
Platinum Electrode ◽  
Activation Parameters ◽  
Enol Form ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Redox Catalyst ◽  
Oscillation Reaction ◽  
Belousov Zhabotinskii Reaction ◽  
Kinetics Of

Oxidation of α-ketoglutaric acid with Ce(IV) ions in a solution of sulphuric acid is a reaction of the first order with respect to both Ce(IV) ions and substrate, is acid catalysed, and its rate is proportional to the reciprocal square of the equilibrium HSO4- concentration. From the temperature dependence of the rate constant in 1.5M-H2SO4, the activation parameters were determined as ΔH##f = 57 kJ/mol and ΔS##f = -45 J mol-1 K-1. The redox reaction proper consists apparently of two steps: in the first one, the enol form of α-ketoglutaric acid reacts with Ce(IV) ions with the formation of the corresponding radical; in the second one, the latter is oxidized further with Ce(IV) to give malonic and succinic acids. Conditions are indicated under which α-ketoglutaric acid serves as substrate for the Belousov-Zhabotinskii oscillation reaction in the presence of Ce(IV)-Ce(III) redox catalyst. Oscillations of Ce(IV) and Br2 concentrations, shifted in phase, can be recorded polarographically with a rotating platinum electrode.

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