Anti-corrosion epoxy coatings enhanced by CeO2 grown on carbon nanofibers

Controlled in-situ CeO 2 growth on CNF was achieved via cerium/PAN ratio. • Rough CeO 2 /CNF surface reduces interfacial porosity through mechanical interlocking. • The composite coating combines CNF physical barrier with CeO 2 passivation. • CeO 2 /CNF/EP coating offers superior corrosion protection for carbon steel. Cerium oxide (CeO 2 ) nanoparticles and carbon nanofibers (CNF) are promising fillers for prolonging the service life of epoxy resin (EP) coatings, valued for their corrosion inhibition and mechanical strength. However, their direct application in EP coatings often results in inadequate anti-corrosion performance due to weak interfacial interactions and agglomeration. Here, CeO 2 nanoparticles were in-situ grown on the CNF surface (CeO 2 /CNF) by controlling the amount of cerium salt to polyacrylonitrile, using electrospinning, oxidation, and carbonization processes. The rough CeO 2 /CNF surface provides a larger contact area with the epoxy matrix, promoting strong mechanical interlocking, therefore it can reduce interfacial porosity and improve the barrier properties of the composite coating. The optimized coating of CeO 2 -3/CNF/EP exhibited an excellent anticorrosion performance. The electrochemical impedance spectroscopy (EIS) results showed that the |Z| 0.01 Hz value of CeO 2 -3/CNF/EP coating decreased from 3.65 × 10 8  Ω cm 2 to 1.26 × 10 8  Ω cm 2 after immersion in a 3.5 wt% NaCl solution for 56 days, remaining two orders of magnitude higher than that of pure EP coating and superior to the other coatings. The outstanding corrosion resistance is attributed to the synergistic effect of the mechanical interlocking provided by rough CNF and the corrosion inhibition of a passive film resulted by CeO 2 nanoparticles. Download: Download high-res image (252KB) Download: Download full-size image