3D-printed solar evaporator with seashell ornamentation-inspired structure for zero liquid discharge desalination

Solar-driven interfacial evaporation has enormous promise for fresh water recovery and salt harvesting, but salt accumulation-related challenges stand in its way. Herein, we report a spined groove-ridge pairs inspired by the shell ornamentation of the Vasticardium vertebratum, which addresses salt accumulation by artfully integrating salt reflux into localized salt crystallization. The seashell-mimetic radial V-groove array enables the 3D evaporator to transport water rapidly and directionally, resulting in high-performance water evaporation (similar to 95% efficiency) and localized crystallization. The periodic spines enlightened by the spine-bearing ridge on the seashell provide considerable micro-unit salt reflux. The 2-in-1 integration design endows the three-dimensional evaporator with superior solar-driven zero liquid discharge and excellent long-term salt resistance even when dealing with high-salinity brine (20 wt% NaCl) and a series of heavy metallic salt solutions. Our design offers a new alternative solution to avoiding salt scaling and could advance locally crystallized solar evaporators towards practical applications.

Automated summary

This study presents a spined groove-ridge pairs inspired by seashell ornamentation to address salt accumulation in solar-driven interfacial evaporation. The design enables high-performance water evaporation and localized crystallization, while enhancing salt resistance through salt reflux.