Nanofiber based origami evaporator for multifunctional and omnidirectional solar steam generation

Interfacial solar steam generation is considered as an effective and environment-friendly technology for clean water production. However, the preparation of an evaporator with omnidirectional light harvesting, high evaporation rate, catalytic and antibacterial properties simultaneously remains a great challenge. Herein, we report the Ag nanoparticles decorated MXene nanosheets/polyacrylonitrile (Ag@MXene/PAN) nanofiber based evaporators for high-efficiency, multifunctional and omnidirectional solar steam generation by solution electrospinning technology. The conjunction of Ag nanoparticles and MXene nanosheets not only enhances the broadband light absorption and heat production, but also contributes to the good catalytic and antibacterial performance. Furthermore, the flexibility and foldability of Ag@MXene/PAN nanofiber membranes enable the design of 3D fine-structure evaporator with increased evaporation surface area and optimized light absorption. As a proof of concept, Ag@MXene/PAN nanofiber based origami evaporator is constructed, which demonstrates relatively stable evaporation rates during a wide range of incident angle from 30° to 150°. The maximum evaporation rate reaches 2.08 kg m−2 h−1 under 1 sun illumination, far superior to the state-of-the-art solution-electrospun nanofiber based evaporators. Integration of structure flexibility, high performance and multi-functionality makes the designed nanofiber based evaporator promising for practical clean water production.