Biomimetic Kevlar aerogel for sewage treatment and all-day fresh water production

For the pollution and lack of clean water, many promising materials and methods are adopted to alleviate the urgent issue in the world. However, it remains a challenge to obtain freshwater all-day by sustainable technologies. Herein, inspired by water directional transport and transpiration of lotus root, biomimetic Kevlar nanofibers-based aerogel with stable mechanical property has been fabricated by a directional freezing process at a velocity of 0.04 mm/s. The aerogel exhibits directional water transmission performance with a velocity of 0.5 mm/s, which is due to the vertically distributed channel structure. In addition, the biomimetic aerogel shows high continuous catalytic efficiency of 98.91% for pollutant degradation only by gravity, and excellent antibacterial property. Moreover, the salt-resistant aerogel has an enhanced photothermal conversion efficiency of 81.2% for solar energy-driven seawater desalination, and evaporation velocity of 1.26 kg m−2h−1 is obtained under one solar light. Furthermore, the aerogel shows an excellent fog collecting rate of 1.57 g cm−2h−1 from moisture at night, which benefits from alternating hydrophilic/hydrophobic pattern. The biomimetic aerogel fabricated by smart strategy is expected to be applied to sewage treatment, and freshwater production not only from brine in daytime but fog at night.