Graphene-Driven Galvanic Corrosion Enables Spatiotemporal Cu²⁺ Release in Nanofluid-Infused SLIPS for Dynamic Antifouling Coatings

Marine biofouling constitutes a pervasive biological threat that seriously impedes the sustainable development of the marine economy. Slippery liquid-infused porous surfaces (SLIPS) were typically employed as marine coatings to mitigate biofouling. However, SLIPS are often hindered by rapid lubricant leaching, short service life, and a simple antifouling strategy, thereby limiting their applicability in marine environments. To circumvent the limitations of conventional SLIPS, synergistic antifouling strategies were frequently adopted. In this study, we developed a copper/graphene nanofluid-infused porous surface (Cu/G@uPDMS-oil) utilizing the breath figure method. The nanofluid can be firmly locked into the microstructure within polydimethylsiloxane (PDMS) to form a stable lubricating layer and provide a sustained release of silicone oil due to dynamic hydrogen bonding. In addition, when silicone oil is released from the coating surface, the intrinsic copper (Cu) and graphene (G) nanoparticles come into substantial contact with the surrounding solution, leading to galvanic corrosion. Galvanic corrosion produces synergistic antifouling through a dual mechanism of induced oxidative stress and copper ion (Cu2+) release. Consequently, the resulting coating exhibits high stability, continuous silicone oil leaching, and self-replenishing properties. Due to the labyrinth effect of graphene, the release rate of Cu2+ is significantly diminished to 6.2 μg·cm-2·day-1. Furthermore, this nanofluid-based smooth surface demonstrates superior antibacterial, anti-algal, and anti-conch properties. The developed Cu/G@uPDMS-oil coating holds great potential for significantly mitigating marine biofouling.