The corrosion protection afforded by a commercial rust converter doped with graphene oxide

• Published in: Electrochimica acta Vol. 342; p. 136096
• Main Authors: Díaz, B., Figueroa, R., Nóvoa, X.R., Pérez, C., Pintos, A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 10.05.2020; Elsevier BV
• Subjects: Barrier properties; Corrosion; Corrosion effects; Corrosion prevention; Electrochemical impedance spectroscopy; Gallic acid; Graphene; Graphene oxide; Rust converter; Rusted steel; Rusting; Steel converters; Submerging; Substrates; Barrier properties; Graphene oxide; Rust converter; Rusted steel
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2020.136096

The present work is devoted to study the effect of the Graphene Oxide (GO) addition in the corrosion protection capacity of a commercial Rust Converter (RC). These substances are designed to be applied over corroded surfaces. It is supposed that they react with rust generating a stable layer, which protects to the metallic substrate. The RC used here is a commercial product that contains gallic acid as reactive compound, which reduces the GO added to reduced-GO (r-GO). Electrochemical Impedance Spectroscopy (EIS) was used to characterize the barrier properties of RC and RC + r-GO treatments, both as in free-standing films and in supported coatings on rusted steel. The results suggest that the RC + r-GO treatment generates more stable and protective films. For the interpretation of the impedance diagrams, the semiconducting character of the film obtained from the RC + r-GO treatment was considered. The initial lower impedance values observed in these samples are related to the presence of electronic paths in parallel with the ionic paths. The impedance values remain stable during long-term immersion. On the contrary, samples coated with the RC treatment undergo a continuous impedance decrease indicating a loss of the barrier properties of the coating.