Advances in layered double hydroxides with corrosion inhibitors for effective corrosion protection of magnesium and aluminum alloys: A review

Owing to their distinctive lamellar structure, compositional tunability, and excellent anion-exchange capability, layered double hydroxides (LDHs) can provide both passive barrier protection and active corrosion inhibition. Consequently, LDHs have emerged as highly versatile and extensively investigated platforms for corrosion protection of metallic materials, particularly magnesium (Mg) and aluminum (Al) alloys. The rapid progress in LDH-based corrosion protection highlights the need for a comprehensive review to summarize recent advances and emerging trends. In particular, this review mainly focuses on LDHs as carriers for inorganic and organic corrosion inhibitors, discussing strategies for inhibitor incorporation and the resulting enhancements in the long-term corrosion resistance. The multifunctional roles of LDHs—defect sealing, inhibitor storage and release, chloride entrapment, interfacial adhesion enhancement, and self-healing—are systematically discussed. Despite remarkable progress, several challenges still hinder the practical application of LDH-based corrosion protection systems, including long-term structural stability, precise regulation of inhibitor release kinetics, interfacial compatibility, mechanical durability, and scalable fabrication. Finally, future research directions are discussed, with particular emphasis on environmentally friendly and scalable LDH fabrication, multifunctional and multi-inhibitor system design, quantitative differentiation between active inhibition and passive barrier effects, advanced operando and localized characterization techniques for self-healing and corrosion processes, and industrial implementation under realistic service conditions. Overall, this review provides a comprehensive foundation and forward-looking perspective to guide the development of next-generation LDH-based protective coatings for Mg and Al alloys.