Nanofibrous Aerogels with Vertically Aligned Microchannels for Efficient Solar Steam Generation.

Utilizing solar energy to evaporate seawater or sewage to improve water quality is an environment-friendly and sustainable water treatment technology, which has been widely concerned. However, there are still many challenges for efficient solar vapor generation, such as incapable free floating, low water-transfer rates, low energy efficiency, serious salt precipitation, and short service life. Herein, photothermal conversion nanofibrous aerogels (PTCNFAs) with vertically aligned microchannels inside are fabricated. Because of the orderly framework structure and the good hydrophilicity, the PTCNFAs show excellent underwater compressive fatigue durability (nearly no plastic deformation after 50 compressive cycles) and water-transfer rate (0.5 cm s-1 in the first second). Furthermore, the surface temperature of the PTCNFAs could rise from 28 to 94 °C in air, after being irradiated for 30 s by 1 sun. Benefiting from the excellent mechanical properties, high water-transfer rates, and outstanding photothermal properties, the PTCNFAs are more convenient in application and exhibit an efficient solar water evaporation rate (2.89 kg m-2 h-1), while the energy efficiency under 1 sun is about 90.3%. This work provides a new approach to design and fabricate the solar steam generation materials for water treatment.