Plasmonic nanoheating for versatile water purification membranes

Global water scarcity motivates sustainable clean water production from non-traditional water sources. While existing reverse osmosis (RO) membranes dominate seawater desalination, they are far from ideal for purifying diverse water sources due to inadequate removal of various low-molecular-weight contaminants. Here we overcome this limitation by developing ultraselective polyamide RO membranes via in situ interfacial plasmonic nanoheating integrated interfacial polymerization (IP). The rapid localized heating at the nano-interface of IP boosts the reactivity of monomers, improves the local mass transfer of amine monomers, and facilitates interfacial degassing/vaporization. Consequently, the resultant RO membrane, featuring highly crosslinked polyamide with extensive internal nanovoids, exhibits superior removal for a wide spectrum of toxic and hard-to-remove contaminants found in different water sources, revealing transformative potential for various water treatment scenarios. It also shows a transcendent desalination performance (water permeance of 3.4 l m−2 h−1 bar−1 and NaCl rejection of 99.7%), which further enables efficient desalination of natural seawater for high-quality freshwater, indicating great promise for practical applications. Our study opens a route to develop high-performance RO membranes for effectively purifying diverse water sources towards sustainable clean water production.