This study introduces a novel relay and synergistic anti-corrosion mechanisms by constructing an active anticorrosive coating with nanocontainers through the combination of zinc-based zeolitic imidazolate framework materials (ZIF-8) and layered double hydroxides loaded with molybdate anions (MoO₄^2- LDHs). The incorporation of ZIF-8 provided the material with abundant surface nano-micropores, enhancing its adsorption capacity for corrosive ions such as OH^- and Cl^-. Simultaneously, this adsorption enabled the ZIF-8-loaded NiAl-MoO₄^2- LDH to receive signals induced by Cl^- stimulation or pH changes . After receiving the signals, the corrosion inhibitor MoO₄^2- encapsulated within the NiAl-MoO₄^2- LDH was released responsively and exchanged with Cl^-. The released MoO₄^2- from nanocontainers adsorbed onto localized corrosion sites, forming a passivation film, thereby blocking the diffusion path of Cl^-. Additionally, this study demonstrated that the self-assembly of ZIF-8 effectively reduced the hydrophilicity of LDH and enhanced the resistance of coating to permeability. Through supramolecular interactions between LDH hydroxyl groups, MOF functional groups, and organic epoxy resin, the cross-linking of the coating and the interfacial compatibility of the materials were significantly improved. The Z-type heterojunction composed of nickel-based LDH and metal organic frameworks not only increased the specific surface area and capacitance performance but also provided photo-induced cathodic protection for metal substrates with matched bandgaps. The experimental results showed that the impedance properties of the ZIF-8/NiAl-MoO₄^2- LDH coatings were 28.43 times of pure epoxy after 168 h. This work can provide new insights and assistance for the study of anti-corrosion mechanisms.

The design and performance prediction of efficient anticorrosion materials is a work full of value, novelty, and challenges. In this work, from the perspective of nanostructure and composition, ZnO-based dilute magnetic solid solution (DMSs) with hydrophobic micronano network structure was synthesized through the self-induced effect of raw materials, the impact-resistant network structure, complex micro-channels, and densely nested layers resisted electrolyte intrusion. Further, the doping of mixed valence Mn element endowed the solid solution with dilute magnetic properties, so the Lorentz force from micromagnetic field changed the movement path of electrons produced by the anode reaction to improve the corrosion inhibition ability of the protective layer. Under the synergy of morphology and magnetism, the corrosion resistance of the DMSs materials was 555.4% and 173.8% higher than that of epoxy resin and ZnO shielding layer, respectively. Besides, a valuable phenomenon was found that the photocatalytic property of DMSs materials was positively correlated with their corrosive defense. In conclusion, this research provided a novel design idea for new high-efficiency anticorrosion materials.

Mixed-valence metallic compounds are a class of functional materials with peculiar electrochemical properties. Exploring the correlation between defects and corrosion resistance of mixed-valence metallic compounds is a novel and interesting subject. Through an intelligently designed synergistic process of reduction and directed assembly, not only the directional generation of oxygen vacancies along the normal direction of the (010) crystal plane was achieved, but also the W₁₈O₄₉ mixed-valence metal oxide (MVMO) with a single crystalline phase and an assembled ordered three-dimensional cluster structure of nanorods was obtained. Three attractive effects of oriented oxygen vacancies in W₁₈O₄₉ MVMO were discovered. First, the oxygen vacancy channels realized the directional concentrated transport of oxygen atoms to form dense oxide passivation film. Second, the directional concentrated oxygen vacancies as active centers effectively solved the problem of difficult photoelectron leap and separation of pure-phase semiconductors, realizing photogenerated cathodic protection. Third, the high-energy vacancies endowed the material with antibacterial function, which contributed to the stable existence of the anti-corrosion system. The resistance value of W₁₈O₄₉ MVMO as an anti-corrosion functional material was increased to more than 4.00 times that of the original metal protection layer. The experimental results obtained in this research were of great reference value for revealing the intrinsic mechanism of correlation between oxygen defect orientation of MVMOs and electrochemistry.