FemtosecondLaser Architecting FeCo Oxides EngineeredNi Foam for Magnetically Controllable Adsorption of Bubbles/Oil Droplets

Abstract Industrial development has led to increased pollution from oils and greenhouse gas leakage in marine environments, driving research into stimulus-responsive manipulation platforms for oil and gas adsorption. This study presents an innovative method that combines femtosecond laser processing with vacuum annealing to fabricate a magnetic FeCo/Ni foam. The porous structure and superhydrophobic surface enable efficient adsorption of oil droplets and capture of underwater bubbles. Moreover, the foam can be precisely manipulated in three dimensions underwater using a permanent magnet. Leveraging this capability, we demonstrate applications including oil removal on and below the water surface, obstacle-avoiding droplet transport, and patterned droplet motion. Furthermore, the foam exhibits strong gas-adsorption capacity, facilitating bubble collection and transport through complex underwater environments, and enabling effective gas recovery from gas-rich aqueous media. The developed superwetting material and its straightforward fabrication strategies show broad application potential in water treatment and environmental monitoring.