Hierarchical bioinspired nanocontainer for magnesium alloys: Effective corrosion inhibition and antifouling

Nowadays, despite advancements in anticorrosion technologies, the application of magnesium (Mg) alloys in marine environments continues to encounter significant challenges in corrosion protection against biofouling. Given the limitations of single-component materials, achieving a synergistic protective effect is a critical requirement. This study proposes a multistage slow-release system to fabricate a composite of multistage nanocontainers based on a three-dimensional (3D) bio-template. Specifically, the design integrates the coupling of multiple nanocontainers to leverage the synergistic effects of multistage retardation. The M-CeO₂-LDH/DE coating leverages the porous loading capability of DE, the responsive release function of LDH, and the redox activity of CeO₂, resulting in a significant enhancement of anticorrosion performance while effectively inhibiting the adhesion of sulfate-reducing bacteria (SRB) and Chlorella vulgaris. Furthermore, the study elucidates the effects of multistage nanocontainers on the anticorrosion and antifouling properties of magnesium alloy coatings, as well as the potential mechanism for multistage slow-release protection. As a result, the coating achieved an antimicrobial efficiency of 98.85 % at a corrosion inhibitor loading of 24.9 wt.%, while the corrosion current density at the scratches decreased from 25.2 µA·cm^-2 to -12.5 µA·cm^-2. The M-CeO₂-LDH/DE coating integrates highly effective corrosion resistance, biofouling protection, and excellent mechanical properties. DFT calculations model the varying adsorption behavior of 2-MBI and confirm the multistage release mechanism of the nanocontainer for the corrosion inhibitor. This study not only introduces innovative strategies for developing high-performance protective coatings but also establishes a robust foundation for the broader application of magnesium alloys in marine environments, underscoring their significant potential for engineering applications.