Synergistic Antifouling and Anticorrosion Coating via Controlled Release of Yb³⁺ from Optimized Yb₂O₃/Yb-MOF Composites

To restrict the application of highly toxic antifouling agents, rare earth elements, as green and environmentally friendly materials, have been widely used in the field of marine coatings. Among them, ytterbium oxide (Yb₂O₃) has been demonstrated to have promising application prospects. However, ytterbium oxide faces significant obstacles in achieving long-term antifouling due to the "burst release". In this study, we present a novel antifouling coating composed of ytterbium oxide and ytterbium-based metal-organic framework (Yb-MOF) to trap ytterbium ions (Yb³⁺). This synergistic design offers dual benefits of stability and durability. Through compounding at a specific ratio, this composite coating mitigates the agglomeration of Yb-MOF and the uncontrolled release of Yb₂O₃, thereby achieving a protective effect on aluminum alloys. Additionally, we evaluated the corrosion resistance and anti-algal performance of the coating, indicating that the coating performance does not continuously improve with the increase in ytterbium oxide content. When the ratio of ytterbium oxide to Yb-MOF reaches a specific value, the coating exhibits excellent anticorrosive and antifouling properties, while simultaneously achieving efficient and sustained release of Yb³⁺ in the aquatic environment. This study has supported the application of long-term environmentally friendly composite coatings.