Fabrication and characterization of polypyrrole coatings by embedding antimony modified SnO2 nanoparticles

Polypyrrole (PPy) coatings were successfully electrosynthesized on the carbon steel by embedding SnO2 and Sb-SnO2 nanoparticles (NPs). The associated structural, morphology, hydrophobic, physical properties, anti-corrosion and self-healing performance of these coatings were systematically studied by several tests. XRD results showed that SnO2 had a tetragonal rutile structure and the lattice parameters indicated that Sb ions were successful substituted into SnO2 lattice. The average size of SnO2 NPs was decreased by the incorporation of Sb-SnO2 NPs, which were found through TEM images. The contact angle test showed that the hydrophobic of PPy coatings was greatly enhanced by the incorporation of Sb-SnO2 NPs. SEM results revealed that Sb-SnO2/PPy coating exhibited a more compact and uniform surface than SnO2/PPy coating, hence the physical barrier effect was significantly strengthened. The electrochemical measurements confirmed the excellent anti-corrosion and self-healing ability of Sb-SnO2/PPy coating for a long immersion time in HCl solution. The superior anti-corrosion performance of Sb-SnO2/PPy coating was ascribed to the synergistic effects of the anodic protection combined with the self-healing effect, the excellent physical barrier effect with compact, smooth and hydrophobic coating surface as well as the formation of p-n junction with decreased charge transfer. (C) 2019 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.