Fabrication of graphene oxide–alumina hybrids to reinforce the anti-corrosion performance of composite epoxy coatings

•The GO–Al2O3 sheet hybrids could greatly reinforce the corrosion resistance of composite epoxy coatings.•The Al2O3 nanoparticles (nano-Al2O3) are anchored on GO sheets with the help of 3-aminopropyltriethoxysilane.•The close-packed layered structure of GO could be effectively exfoliated by nano-Al2O3.•The GO–Al2O3 hybrids could be uniformly dispersed in the epoxy matrix.•The anticorrosive mechanisms of GO–Al2O3/epoxy coatings were tentatively discussed. Graphene oxide–alumina (GO–Al2O3) sheet hybrids were fabricated using GO as a precursor, then anchoring Al2O3 on GO sheets with the help of 3-aminopropyltriethoxysilane. The structure of hybrids can be measured by FT-IR, XPS, XRD, SEM and TEM. Composite epoxy coatings with same concentrations of GO, Al2O3, and GO–Al2O3 hybrids, among them, GO–Al2O3 hybrids not only achieved an homogeneous dispersion and compatibility in epoxy resin, but exhibited an obvious superiority in reinforcing the anti-corrosion performance of epoxy coatings. Furthermore, the anticorrosive mechanisms of GO–Al2O3/epoxy coatings were tentatively discussed.