Influence of embedded ZnAlCe-NO3− layered double hydroxides on the anticorrosion properties of sol–gel coatings for aluminum alloy

• ZnAlCe-LDHs were synthesized in the presence of different concentrations of Ce.
• Ce (III) was successfully inserted into the sheets of LDH.
• Two phases were formed when Ce/(Al + Ce) atomic ratio was higher than 0.05.
• ZnAlCe-LDH nanoparticles were embedded into sol–gel film on aluminum alloy.
• The anticorrosion property of coating system was enhanced after embedding LDHs.

A protective coating was designed by dispersing Ce-doped ZnAl layered double hydroxides (ZnAlCe-LDHs) nanoparticles in hybrid sol–gel (SiOx/ZrOx) layer on aluminum alloy AA2024. The concentration of cerium in synthesized LDHs was varied to ascertain the optimum condition for anticorrosion performance. The LDH nanoparticles were characterized in terms of structure, morphology and chemical composition. It was found that Ce (III) was inserted into the sheets of LDHs and two mixture phases of LDHs and CeO2 were formed when the atomic ratio of Ce/(Al + Ce) was higher than 0.05. The sol–gel coating embedded with LDHs (Ce/(Al + Ce) = 0.1) exhibited high corrosion resistance, probably due to the synergistic inhibition of ZnAlCe-LDHs and CeO2 nanoparticles.