Kinetic characterization of Prussian Blue-modified graphite electrodes for amperometric detection of hydrogen peroxide |
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Authors: | Raluca C Cretu Delia M Gligor Laura Muresan Ionel Catalin Popescu Liana M Muresan |
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Affiliation: | (1) Department of Physical Chemistry, Babes-Bolyai University, Str. Arany Janos, no. 11, 400028 Cluj-Napoca, Romania |
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Abstract: | Prussian Blue-modified graphite electrodes (G/PB) with electrocatalytic activity toward H2O2 reduction were obtained by PB potentiostatic electrodeposition from a mixture containing 2.5 mm FeCl3 + 2.5 mm K3Fe(CN)6] + 0.1 m KCl + 0.1 m HCl. From cyclic voltammetric measurements, performed in KCl aqueous solutions of different concentrations (5 × 10−2–1 m), the rate constant for the heterogeneous electron transfer (k
s) was estimated by using the Laviron treatment. The highest ks value (10.7 s−1) was found for 1 m KCl solution. The differences between the electrochemical parameters of the voltammetric response, as well as the shift of the formal potential, observed in the presence of Cl− and NO3− compared to those observed in the presence of SO42− ions, points to the involvement of anions in the redox reactions of PB. The G/PB electrodes showed a good electrochemical stability proved by a low deactivation rate constant (0.8 × 10−12 mol cm2 s−1). The electrocatalytic efficiency, estimated as the ratio
, was found to be 3.6 (at an applied potential of 0 mV vs. SCE; Γ = 5 × 10−8 mol cm−2) for a H2O2 concentration of 5 mm, thus indicating G/PB electrodes as possible H2O2 sensors. |
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Keywords: | amperometric sensors hydrogen peroxide modified graphite electrodes Prussian Blue |
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