Fabrication of inhibitor anion-intercalated layered double hydroxide host films on aluminum alloy 2024 and their anticorrosion properties

ZnAl layered double hydroxide (LDH) host films have been synthesized on aluminum alloy 2024 substrate via a facile crystallization method, and then intercalated with different corrosion inhibitor anions (vanadate, molybdate, and 2-mercaptobenzothiazolate). The structures, compositions, and morphologies of the as-synthesized films before and after the anion-exchange reaction were characterized by means of glancing-angle X-ray diffraction, Fourier transform infrared, X-ray photoelectron spectroscopy, and scanning electron microscope techniques. The anticorrosion performance of films was evaluated by potentiodynamic polarization and salt spray test. The results show that all inhibitor anions are successfully intercalated in the layered galleries, providing enhanced corrosion protection for the substrate alloy. The anticorrosion abilities of films loaded with inhibitor anions are ordered as LDH-VO3 > LDH-MBT > LDH-MoO4 > LDH-NO3.