Nacre-inspired robust antifouling amorphous coating via in-situ constructing 3D interconnected diffusion channels

Achieving a delicate synergy between mechanical robustness and antifouling attributes in coatings remains a formidable challenge for marine applications. Inspired by the assembly of nacre, we present a novel approach to fabricate a nacre-like metallic coating. This coating comprises an amorphous matrix with excellent anti-corrosion and anti-wear properties, as well as Cu-rich 3D interconnected channels for antifouling function. The coating is produced by high velocity oxygen fuel (HVOF) thermal spraying of surface-modified Fe-based amorphous powders with a Cu-layer. The resulting coating exhibits exceptional mechanical robustness, including high resistance to erosion, abrasion, and impact, surpassing conventional polymer antifouling coatings. Furthermore, the controlled Cu⁺ leaching capability of the in-situ constructed 3D interconnected diffusion channels, facilitated by the Cu-rich intersplats, contributes to the remarkable antifouling performance. This includes nearly 100% resistance to bacterial adhesion after 1 day of immersion and over 98% resistance to algal attachment after 7 d of immersion, resulting in a prolonged service lifetime. Notably, even after 200 cycles of wear damage, the Cu-modified amorphous coating still maintains its excellent antifouling properties. The Cu-rich intersplats play a critical role in transporting and sustainably leaching Cu ions, thereby accounting for the outstanding antifouling performance. Ultimately, we aim to advance the design of high-performance coatings suited for diverse marine applications, where both the mechanical robustness and antifouling properties are essential.