Efficient Fabrication of Micro/Nanostructured Polyethylene/Carbon Nanotubes Foam with Robust Superhydrophobicity, Excellent Photothermality, and Sufficient Adaptability for All-Weather Freshwater Harvesting

The integration of fog collection and solar-driven evaporation has great significance in addressing the challenge of the global freshwater crisis. Herein, a micro/nanostructured polyethylene/carbon nanotubes foam with interconnected open-cell structure (MN-PCG) is fabricated using an industrialized micro extrusion compression molding technology. The 3D surface micro/nanostructure provides sufficient nucleation points for tiny water droplets to harvest moisture from humid air and a fog harvesting efficiency of 1451 mg cm(-2) h(-1) is achieved at night. The homogeneously dispersed carbon nanotubes and the graphite oxide@carbon nanotubes coating endow the MN-PCG foam with excellent photothermal properties. Benefitting from the excellent photothermal property and sufficient steam escape channels, the MN-PCG foam attains a superior evaporation rate of 2.42 kg m(-2) h(-1) under 1 Sun illumination. Consequently, a daily yield of approximate to 35 kg m(-2) is realized by the integration of fog collection and solar-driven evaporation. Moreover, the robust superhydrophobicity, acid/alkali tolerance, thermal resistance, and passive/active de-icing properties provide a guarantee for the long-term work of the MN-PCG foam during practical outdoor applications. The large-scale fabrication method for an all-weather freshwater harvester offers an excellent solution to address the global water scarcity.

Automated summary

The integration of fog collection and solar-driven evaporation using micro/nanostructured polyethylene/carbon nanotubes foam allows for efficient water harvesting from humid air and high evaporation rates under sunlight. The foam achieves a fog harvesting efficiency of 1451 mg cm(-2) h(-1) at night and an evaporation rate of 2.42 kg m(-2) h(-1) under 1 Sun illumination. This technology offers a promising solution to address the global freshwater crisis and can be applied in practical outdoor settings.