Nanostructured photocatalytic coatings for corrosion protection and surface repair

• Published in: Surface & coatings technology 2013-12, Vol.237, p.320-327
• Main Authors: He, Xingliang, Chiu, Chengwei, Esmacher, Mel J., Liang, Hong
• Format: Article
• Language: English
• Subjects: Applied sciences; Coatings; Corrosion; Corrosion environments; Corrosion prevention; Corrosion protection; Cross-disciplinary physics: materials science; rheology; EIS; Electrochemical impedance spectroscopy; Exact sciences and technology; Materials science; Metals. Metallurgy; Nanostructure; Nanostructured coating; Physics; Production techniques; Protective coatings; Repair; Surface reconstruction; Surface treatment; Surface treatments; Titanium dioxide
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2013.06.038

Corrosion is one of the most destructive processes in materials induced by environment. Protection and repair of metallic surfaces are major challenges in many engineering applications. We report a novel polyelectrolyte nanostructured coating incorporating the corrosion inhibitor, 8-hydroxyquinoline (8-HQ), into titanium dioxide (TiO2) nanoparticles (NPs). The potentiodynamic polarization measurements and real-time electrochemical impedance spectroscopy (EIS) monitoring demonstrated that the nanostructured coating protected aluminum (Al) from corrosion. Photocatalytic TiO2 was able to release incorporated 8-HQ only with the exposure to UV light resulting in a self-healing effect. Real-time EIS results showed that a new passivated layer was formed after 8-HQ molecules were released. The research in interfaces brings insights in understanding new aspects of corrosion and surface repair. •A nanostructured photocatalytic coating.•Combination of structural and electrochemical analyses.•Enhanced corrosion resistance of aluminum substrate.•Optical repair of a corroded surface.