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

Abstract

AbstractThe 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 ≈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.