Simultaneous Fresh Water Collection and Li⁺ Selective Adsorption Enabled by A Salt‐Resistant Separated Solar Evaporator

Abstract

Solar‐driven interfacial evaporation (SIE) of brine may solve the fresh water shortage issue but suffers from salt‐fouling. Meanwhile, adsorption can extract valuable lithium (Li) from brine but is hampered by low adsorption capacity/rate, additional energy input and low selectivity, etc. Here, as a proof‐of‐concept, the design of a separated solar evaporator (S‐evaporator) is reported for simultaneously efficient fresh water collection and Li+ selective adsorption by SIE of brine, accomplishing their complementation using only sunlight. The S‐evaporator consists of a tilted n‐shaped H2TiO3‐modified fabric and a photothermal sheet on it. The superhydrophilic fabric transports brine to the photothermal sheet and provides affluent sites for Li+ adsorption. The photothermal sheet promotes SIE and enhances Li+ adsorption by significantly increasing the fabric's temperature. Consequently, simultaneous fresh water collection and Li+ selective adsorption are realized by the S‐evaporator. Under 1 kW m−2 illumination, the S‐evaporator shows long‐term stable evaporation rate (1.51 kg m−2 h−1) for 20 wt% brine, high Li+ adsorption capacity (20.09 mg g−1), good Li+ adsorption selectivity from real brine and good cycle stability. The S‐evaporator has great application potential for efficiently extracting fresh water and Li+ from brine as demonstrated by the large SIE setup in real outdoor conditions.

All-Biomass-Based Solar Steam Generator with Deep Eutectic Solvent Lignin Porous Carbon/Silver Nanoparticle Coatings for Efficient Water Evaporation

“…Generally, the improvement of water evaporation efficiency depends on the design of the interface evaporation device: (1) a floatable substratum with an abundant porous structure for water transportation and (2) high-performance photothermal conversion materials on top for efficient interface water evaporation. Apart from water evaporation, additional functionalities such as antibacterial, 7 selective metal ions enrichment, 8 electricity cogeneration, 9 and pollutants degradation with an advanced oxidation process have been developed to expand the applications of various evaporation devices. 10 Wood is an abundant and renewable natural material that possesses several unique properties, such as self-floating ability, low-tortuosity channels, and a hierarchical porous structure.…”