One-step hydrothermal fabrication of Co-MOFs/LDH superhydrophobic composite coating with corrosion resistance and wear resistance on anodic aluminum oxide

In recent years, metal-organic framework materials (MOFs) have garnered significant attention in the field of metal corrosion protection. In this study, novel Co-MOFs were synthesized using cobalt nitrate as the metal source and 4,4 '-bipyridine as the organic ligand. A one-step solvothermal method was employed to synthesize a black MOFs/LDH composite coating, integrating corrosion resistance, friction reduction, and hydrophobicity into a single coating. The successful reaction between metal ions and organic ligands was confirmed through FTIR, FE-SEM, EDX, XRD, and XPS characterization tests. Cross-sectional SEM and EDX analyses demonstrated the successful synthesis of the coating. Electrochemical tests indicated that after 14 days of immersion in 3.5 wt% NaCl, the composite coating exhibited the lowest corrosion current of 2.23 x 10-9 A center dot cm- 2, outperforming the aluminum substrate (5.99 x 10-6 A center dot cm- 2) and anodized aluminum (7.08 x 10- 7 A center dot cm- 2). Hydrophobicity tests showed that without additional modification with low surface energy substances, the composite coating had a contact angle of 154.7 degrees, demonstrating excellent hydrophobicity. Tribological tests revealed that the composite coating exhibited superior tribological performance, with a friction coefficient of 0.3.