Artificial transpiration with asymmetric photothermal textile for continuous solar-driven evaporation, spatial salt harvesting and electrokinetic power generation

Abstract Solar-driven interfacial evaporation opens up promising opportunities to alleviate the growing concern of freshwater and energy shortage. However, with ongoing seawater evaporation, the emergence of salt crystallization on the evaporation surface will undermine the water evaporation rate. Herein, a novel asymmetric fluidic evaporator enabling edge-preferential crystallization, gravity-assisted salt harvesting and drenching-induced electrokinetic power generation is designed by asymmetrically depositing TA-MoS2 nanosheets on UIO-66-NH2-modified PAN textile. Benefiting from the self-manipulated saline water transport, this evaporator can spatially isolate the crystallized salts from the evaporation surface, enabling continuous vapor generation and salt harvesting during 60 h of non-stop solar desalination with 7.5 wt% saline. Simultaneously, by taking advantage of the formed gradient electric double layers in asymmetric nanochannels, stable saline-drenching induced voltage generation of 0.568 V is achieved via this wet textile evaporator only. Furthermore, this evaporator shows efficient organic contaminants removal ability, and insignificant decrease is observed in the water evaporation rate and power generation after 60 h running and 30 times washing. This work not only demonstrate a scalable multifunctional asymmetric solar evaporator for continuous seawater desalination along with concurrent salt harvesting and electricity generation, but also advances their scalable and sustainable applications in practical seawater desalination for resource recovery and energy generation/storage.