Construction of dual-ion co-doped LDH coatings on magnesium alloys for marine applications: Achieving self-healing and anti-biocorrosion properties

A corrosion-resistant coating for Mg alloys applied in marine environments is developed, integrating self-healing and antibacterial functions. It comprises an inner microporous MgO layer and an outer layer of layered-double-hydroxides (LDH) co-doped with MoO₄²⁻ and deprotonated 2-mercaptobenzothiazolium (MBT⁻), forming Mo-S bonds. This dual-ion doping strategy enhances corrosion resistance by accelerating ion release, promoting self-healing through weakened bonding between the doped ions and LDH octahedra due to the formed Mo-S bonds. Released MBT⁻ also provides high antibacterial rate against Staphylococcus aureus (93.76 %) and mitigate biocorrosion. This approach offers an effective strategy for a protective coating construction on Mg in marine applications.