TY - JOUR
T1 - Tin passivation in alkaline media
T2 - Formation of SnO microcrystals as hydroxyl etching product
AU - Palacios-Padrós, A.
AU - Caballero-Briones, F.
AU - Díez-Pérez, I.
AU - Sanz, F.
N1 - Funding Information:
A.P.-P. thanks MEC for financial support through an FPU grant. I.D.-P. thanks FP7-PEOPLE-2010-RG-277182 and the Ramon & Cajal programme from MICINN (Spain) for financial support. F.C.-B. acknowledges financial support from CONACYT 151679Q and SIP20131887 . Technical assistance from the CCIT-UB (Molecular Spectroscopy, SEM, Nanometric Techniques, Surface Analysis and XRD units) is recognized. A. C. Aragonès is acknowledged for the fruitful discussions. Funding from MICINN (Spain) through Projects CTQ2007-68101-C02-01 and CTQ2012-36090 is granted.
PY - 2013
Y1 - 2013
N2 - The mechanism of the electrochemical passivation on Tin electrodes in 0.1 M NaOH is studied at low scan rates in a wide potential range. To this aim, tin oxide layers were grown on a polycrystalline tin surface under potentiostatic conditions in both the active and passive electrochemical potential ranges, and characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Raman spectroscopy and electrochemical impedance spectroscopy (EIS). The results show that the first anodic process in the active region corresponds to the formation of a SnO·nH2O prepassive layer that is removed upon increasing the applied potential due to surface etching occurring at the metal/oxide interface. During the etching process, Sn 2+ ions supersaturate at the electrode vicinity thus forming a SnO crystalline phase on top of the electrode surface in the presence of the alkaline medium. At higher anodic potentials, near the passive plateau, the etching process ceases and the current drops due to the formation of a n-type Sn(IV)-based oxide at the metal/SnO interface that provides an efficient electronic passivation of the electrode.
AB - The mechanism of the electrochemical passivation on Tin electrodes in 0.1 M NaOH is studied at low scan rates in a wide potential range. To this aim, tin oxide layers were grown on a polycrystalline tin surface under potentiostatic conditions in both the active and passive electrochemical potential ranges, and characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Raman spectroscopy and electrochemical impedance spectroscopy (EIS). The results show that the first anodic process in the active region corresponds to the formation of a SnO·nH2O prepassive layer that is removed upon increasing the applied potential due to surface etching occurring at the metal/oxide interface. During the etching process, Sn 2+ ions supersaturate at the electrode vicinity thus forming a SnO crystalline phase on top of the electrode surface in the presence of the alkaline medium. At higher anodic potentials, near the passive plateau, the etching process ceases and the current drops due to the formation of a n-type Sn(IV)-based oxide at the metal/SnO interface that provides an efficient electronic passivation of the electrode.
KW - SnO electrosynthesis
KW - SnO microcrystals
KW - Stoichiometric
KW - Tin etching
KW - Tin passivation
UR - http://www.scopus.com/inward/record.url?scp=84883881520&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2013.07.200
DO - 10.1016/j.electacta.2013.07.200
M3 - Artículo
SN - 0013-4686
VL - 111
SP - 837
EP - 845
JO - Electrochimica Acta
JF - Electrochimica Acta
ER -