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A study on oxygen reduction inhibition at pyridine‐terminated self assembled monolayer modified Au(111) electrodes
Author(s) -
Muglali Mutlu Iskender,
Bashir Asif,
Rohwerder Michael
Publication year - 2010
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200983321
Subject(s) - monolayer , chemistry , linear sweep voltammetry , electrochemistry , scanning tunneling microscope , oxygen , cyclic voltammetry , electrode , inorganic chemistry , analytical chemistry (journal) , photochemistry , materials science , nanotechnology , organic chemistry , biochemistry
Abstract The electroreduction of oxygen on self‐assembled monolayers (SAMs) of various pyridinedisulfides and pyridinethiols on Au(111) surfaces has been investigated in alkaline solutions. Electrochemical experiments that were carried out in three‐electrode cell reveal a good correlation between the chain‐length of thiol molecules and the oxygen reduction inhibition of the resulting adlayer films. The effect of retarded diffusion of oxygen through the protective film has been investigated by forming additional layer of immobilized cytochrome c (cyt.c) metalloprotein on pyridine moiety during linear sweep voltammetry (LSV) scans. At sufficiently negative cathodic potentials the electrochemical reaction rate has been observed to increase together with the density of defects. Morphological changes at different levels of cathodic polarization were investigated by ex situ scanning tunneling microscopy (STM), indicating oxygen reduction reaction (ORR) induced structural defects at the metallorganic interface.