Multifunctional solar water harvester with high transport selectivity and fouling rejection capacity

Abstract

Shortage of clean water continues to grow around the world, and the recent solar-powered interfacial system has emerged as a sustainable, efficient and CO2-neutral approach to produce clean water. However, complex contaminants in surface water accompanied with environment pollution set huge obstacles for harvesting clean water via previous strategies. Here we develop a solar-powered graphene/alginate hydrogel (GAH)-based clean water extractor of super resistance to the transport of complex contaminants and ultra-antifouling capacity. This GAH features a high selectivity in water transport by rejecting >99.5% of volatile organic compounds, >99.3% of ions (Na+, Mg2+, K+ and Ca2+) and 100% of non-volatile organic compounds and bacteria; meanwhile, GAH is capable of rejecting oil adhesion by forming a large contact angle >140° under water, deactivating nearly 100% bacteria on surface and preventing salt crystallization. Given such promising adaptability to a wide environment, this GAH can directly convert surface water of complex components into safe drinkable water.