The electrochemical behavior of molybdenum electrode in acetic, formic and oxalic acid solutions is studied. The effect of immersion time, composition medium, applied voltage, applied current density and scanning rate is investigated using potentiodynamic, potentiostatic and galvanostatic polarization measurements.The stability of the oxide film formed on Mo electrode is affected by both the formation medium and the applied potential. In 0.5N oxalic acid, the critical applied voltage below which the current start to oscillate is equal to -80 mV. The rate of dissolution of anodic oxide film formed on Mo in oxalic acid is very rapid compared with that formed in acetic and formic acids. Also in oxalic acid solutions Mo is notably affected by applied current density in which reciprocal capacitance, C s -1 , decrease with increasing applied current density. On the contrary in acetic and formic acids Mo did not affect. In acetic acid solution, the time of anodization has little or no effect on the dissolution process.
Potentiodynamic behaviour of tin electrode in citric, oxalic, maleic and malic acids was studied at room temperature. The various electrochemical parameters were calculated. In addition, the metallographic structure of tin surface electrode was examined for some solutions using scanning electron microscope (SEM). The anodic E/I curves were characterized by active-passive transition state. The anodic active region was due to the formation of soluble Sn(II) species. The passivity of tin anode was related to the hydrolysis of Sn(IV) and precipitation of Sn(OH)4 film on the anode surface. The addition of different percentages of sucrose to (1 M) of all organic acids used inhibited the anodic dissolution of tin electrode and enhanced the attainment of passivity. While the addition of sodium chloride accelerated the corrosion of tin and delayed the establishment of passivation. In citric, maleic and malic acids, inhibition was of mixed type and occurred by adsorption of SnL complex molecules following the Temkin isotherm. In case of oxalic acid the inhibition was found to be predominantly anodic occurring by adsorption of SnL2 complex and following the Langmuir isotherm.…
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.