Characterization of anodic tin passive films formed in citrate buffer solutions

Electrochemical studies on the anodic behavior of tin in citrate buffer solutions

“…Moreover, s 2 increases linearly with E f while s 3 results independent of E f . These facts are also consistent with the ascription of species made above, if one bears in mind the conclusions of previous works [8,[10][11].…”

“…Based on XPS results obtained on tin in KOH [8] and in phthalate buffer pH 5.5 [9] Keller and Strehblow, modeled the passive film in terms of a monolayer of SnO that is not further oxidized at higher anodic potentials and that is covered by a thicker layer of SnO 2 with an outer portion of Sn(OH) 4 . This interpretation was consistent with the electrochemical data analysis of passive films formed on tin in citrate solutions recently published [10,11].…”

“…Even though the experimental methodology, as used in this work, was not aimed at proposing a growth mechanism for the different layers formed, some related aspects previously put forward [10,11], can be confirmed. For example, direct formation of a monomolecular layer of SnO and passive film formation resulting from hydrolysis of Sn(IV) species with subsequent dehydration.…”

“…According to previous works [8,10,11] the thickness of the Sn(IV) containing layer is larger than that of the Sn(II)-species. Thus, considering Faraday's law (vide infra), it is reasonable to ascribe the reduction of SnO 2 to the potential arrest associated with the longer transition time (s 2 ).…”

Research into corrosion and electrocatalytic properties of the modified oxide films on tin

“…The formation of protective layer of tin dioxide occurs during oxidation of the metal [5]. Post-oxidation of tin monoxide appears to be unlikely [6]. The presence of tartaric acid in the solution that is in contact with the passivated tin surface contributes to the accelerated dissolution of metal and reduces protective effect of a tin dioxide film [1].…”