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 strategy to produce clean water. However, complex contaminants in surface water in accompany with environment pollution set huge obstacles for harvesting clean water via using sunlight as the energy input. Inspired by the surface structure of fish-scale, we herein 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 (VOCs), > 99.3% of ions (Na+, Mg2+, K+, Ca2+), 100% of non-volatile organic compounds (NOCs) and bacteria; meanwhile GAH is capable of rejecting oil adhesion by forming large contact angle >140o 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 water that meets drinking standards.