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Electrooxidation of 2‐Mercaptopyridine‐ N ‐oxide (Pyrithione) at Carbon Electrodes versus Mercury Electrodes
Author(s) -
Ruiz Montoya M.,
Marín Galvín R.,
Rodríguez Mellado J. M.
Publication year - 1998
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/(sici)1521-4109(199810)10:15<1030::aid-elan1030>3.0.co;2-e
Subject(s) - electrode , electron transfer , inorganic chemistry , chemistry , electrochemistry , mercury (programming language) , glassy carbon , oxide , gibbs free energy , analytical chemistry (journal) , materials science , cyclic voltammetry , chromatography , organic chemistry , thermodynamics , physics , computer science , programming language
The electrooxidation of the bactericide and fungicide agent 2‐mercaptopyridine‐ N ‐oxide (PySH), or pyrithione, was investigated by using mercury (Hg), glassy carbon (GCE), plastic formed carbon (PFCE) and paste (CPE) electrodes. From controlled‐potential electrolyses or chronoamperometric measurements, the number of electrons involved in the oxidation processes was found to be close to unity in all cases. Voltammetric measurements showed that the irreversibility of the electron transfer must be related to the roughness and ordering in the surface of the electrode material: as the amorphous character of the carbon electrode was increased, the transfer appeared faster. Other effects as the O/C ratio or the removal of impurities can also influence the reversibility of the transfer. The rate constants of the electron transfers at zero potential were obtained. In addition, the extension of the adsorptive oxidation decreased when the amorphous character of the electrode was increased, but the Gibbs free enthalpy of this process did not vary from one electrode to another nor for the Hg electrode.