Facile fabrication of ZnAl layered double hydroxide film co-intercalated with vanadates and laurates by one-step post modification

Abstract

ZnAl layered double hydroxide (ZnAl-LDH-VOx-La-one step) film co-intercalated with inhibitors (vanadates) and low-surface-energy substance (laurates) was prepared on Al substrate by a hydrothermal method followed by a one-step modification process in the mixed solution of vanadates and laurates. The morphology, composition and structure was characterized carefully by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The obtained results indicated that vanadates and laurates were successfully intercalated in the LDH interlayer space. The corrosion protection ability of this film was evaluated by electrochemical impedance spectra (EIS). It was demonstrated that ZnAl-LDH-VOx-La-one step film could provide more effective protection for the underlying Al substrate compared with ZnAl-LDH films only intercalated with vanadates or laurates, most importantly, even better protection than that of the sample prepared by two steps with the resistance of the inner LDH layer almost four times higher after immersion in 3.5 wt% NaCl for 1 h.