Study on the corrosion and self-healing behavior of different anion-intercalated layered double hydroxides coatings on Mg alloy surfaces

Using hydrothermal and co-precipitation techniques, layered double hydroxides (LDHs) coatings comprising three inorganic anions (nitrate, molybdate, and stannate) and the organic anion sodium dodecyl sulfate (SDS) were created for Mg alloy surfaces. XRD, FT-IR, XPS, SEM, and EDS were used to evaluate their shape, structure, and chemical content. Electrochemical impedance spectroscopy (EIS), hydrogen evolution tests, and potentiodynamic polarization were used to assess the corrosion resistance of the LDHs coatings. Because the coatings were composed of continuously formed LDHs nanosheets, they provided a tremendous lot of protection to the Mg substrate. The single-frequency EIS, strain-potential curves, and scratch tests were used to investigate the static and dynamic self-healing properties. Among the coatings, LDHs-SDS demonstrated optimal self-healing, with a repair potential of -1.09 V and sustained stability, attributed to SDS's physical adsorption. The LDHs-MoO 4 2- coating exhibited a self-healing duration of 33,330 s, effectively repairing larger cracks due to molybdate ion exchange, which inhibited corrosion by forming a protective layer at the cracks.