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

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.