Bioinspired design of electrospun nanofiber based aerogel for efficient and cost-effective solar vapor generation

Electrospun nanofiber based aerogels are attracting great attention for solar vapor generation due to their unique three-dimensional (3D) porous structure, light weight, enhanced solar absorption and thermal insulation property. However, the commonly used sophisticated and expensive preparation process, as well as the relatively low solar vapor generation performance, have limited their wide applications. Herein, luffa-inspired electrospun polyacrylonitrile/carbon nanotubes (PAN/CNTs) nanofiber based aerogels with hierarchical pore structure were designed and fabricated in an eco-friendly crosslinking and simple freeze-drying method. The nanofiber based aerogel combined the synergistic photothermal effect of polydopamine (PDA) and CNTs, resulting in a high light absorption of 94.8%. Furthermore, the 3D interconnected structure formed by the electrospun nanofibers greatly reduced the enthalpy of vaporization. The composite aerogel achieved fast evaporation rate of 2.13 kg m-2 h-1 and high solar-vapor conversion efficiency of 94.5% under one sun, superior to most of the reported electrospun nanofiber based solar vapor generators. This scalable, eco-friendly and cost-effective aerogel provides a straightforward approach for producing clean water efficiently.