کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10269224 | 459718 | 2011 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Electrochemical evaluation of the a carbon-paste electrode modified with spinel manganese(IV) oxide under flow conditions for amperometric determination of lithium
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
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چکیده انگلیسی
The participation of cations in redox reactions of manganese oxides provides an opportunity for development of chemical sensors for non-electroactive ions. This paper describes the amperometric determination of lithium ions using carbon-paste electrode modified with spinel manganese(IV) oxide under flow conditions. Systematic investigations were made to optimize the experimental parameters for lithium sensor by flow injection analysis. The detection was based on the measurement of anodic current generated by oxidation of Mn(III) to Mn(IV) at the surface of the electrode and consequently the lithium ions extraction into the spinel structure. An operating potential of 0.50 V (vs. Ag/AgCl/3 KCl mol/L) was exploited for amperometric monitoring. The amperometric signal was linearly dependent on the lithium ions concentration over the range 4.0 Ã 10â5 to 1.0 Ã 10â3 mol Lâ1. The equilibrium constant of insertion/extraction of the lithium ion in the spinel structure, apparent Gibbs energy of insertion, and surface coverage of the electrode with manganese oxide, were calculated by peak charge (Q) in different concentration under flow conditions. Considering selectivity, the peak charge of the sensor was found to be linearly dependent on the ionic radius of the alkaline and earth-alkaline cations.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 56, Issue 5, 1 February 2011, Pages 2552-2558
Journal: Electrochimica Acta - Volume 56, Issue 5, 1 February 2011, Pages 2552-2558
نویسندگان
Paulo A. Raymundo-Pereira, Cibely S. Martin, Marcio F. Bergamini, Nerilso Bocchi, Marcos F.S. Teixeira,