Abstract
Direct solar steam generation (DSSG) is well-proven to be a sustainable and effective technique to provide high-quality freshwater supply. However, it customarily suffers from severe salt accumulation, especially for treating strong brine, becoming a fatal bottleneck for approaching its commercial applications. Herein, we developed a DSSG with potent siphon-drop mode to achieve powerful self-absorbing and self-desalting, in which the 3D cone-shaped self-supporting polydopamine and polyethyleneimine co-coated poly(acrylonitrile-styrene-acrylate) (PDA-PEI@ASA) used as photothermal material (PTM). Source water can be spontaneously and continuously pumped to the top of water-evaporating surface of PTM via strong siphon effect, and the top-down active water diffusion on evaporating surface can effectively take the salts away from the system. Such above features give the DSSG real-time antifouling nature and hence address the fatal issue of salt accumulation. Accordingly, when continuously treating a near-saturated brine (20% NaCl) for at least 168 h, no obvious salts deposition can be found with a steady water evaporation rate of ∼2.550 kg m–2 h−1. This work could help shed novel light on the design of practical DSSG systems toward efficient lasting freshwater extraction, holding great promise for global water scarcity.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have