Large CeO2 nanoflakes modified by graphene as barriers in waterborne acrylic coatings and the improved anticorrosion performance

•1, Graphene were linked to CeO2 nanoflakes by p-aminobenzoic acid as barriers.•2, The mentioned barriers can improve the anticorrosion performance of acrylic coating.•3, Corrosion current of above coating can be low to 1/106 value of pure acrylic coating.•4,The hydrophobicity of the coating can affect anticorrosive ability of the coating. Large CeO2 nanoflakes in diameter of 3∼5 μm were used as barriers in waterborne acrylic coating to improve the anticorrosion. Meanwhile, graphene (Gr) was adopted to modify the CeO2 nanoflakes which were linked by bifunctional ligand p-aminobenzoic acid (PABA), forming a more efficient barrier Gr-P-CeO2. The electrochemical test indicated that the acrylic coating using Gr-P-CeO2 as barrier improved the anticorrosion performance obviously when compared with the coatings using pure Gr, pure CeO2 nanoflake, and the Gr-CeO2 without PABA linking. The composite coating with Gr(3%)-P-CeO2 had a corrosion current (icorr) of 2.29 × 10−7 A/cm2, and coating resistance(Rc) was 3.53 × 103 Ωcm2. The best icorr was almost 53 times lower of CeO2 coating, and 48 times lower of Gr-CeO2 coating.