Solar-Powered High-Efficiency Interface Evaporator Based on Polyimide Nanofiber Aerogel for Water Purification

Interfacial solar steam generation has been regarded as a promising method to produce freshwater from seawater. Nevertheless, achieving simultaneous optimization of high evaporation efficiency along with stability and durability remains a substantial obstacle for polyimide (PI)-based solar evaporators. Herein, a hierarchically structured PI/MXene composite aerogel was prepared by electrostatic spinning, freeze-drying, and thermal imidization. The combination of PI nanofibers and MXene endows the hybrid aerogels with three-dimensional porous structures, intriguing hydrophilicity, and high light absorption, resulting in augmented light-to-heat conversion efficiency. Furthermore, the PI/MXene composite aerogel exhibits an excellent water evaporation rate of 1.459 kg m–2 h–1 under 1 sun with a high photothermal conversion efficiency of 95.6%. The PI/MXene composite aerogel possesses distinct salt resistance, eminent structural stability, and remarkable cycling stability with an evaporation rate of 1.24 kg m–2 h–1 over 10 cycles. This work provides a prospective strategy for constructing highly efficient solar-powered generator with stable performance for practical application in seawater desalination.