Abstract
Freshwater crisis seriously challenges human survival and development, especially in arid regions. Solar-driven interfacial evaporation has recently received tremendous interest for collecting clean water, yet is only feasible in regions with available surface water. Atmospheric water harvesting is independent of surface water but requires high RH, additional energy input and complex equipment. Here, we demonstrate efficient water harvesting from desert soil in very dry regions (air RH < 10%, soil moisture content < 3%) via interfacial solar heating under natural sunlight. The water harvesting device, composed of merely a thin layer of activated carbon (for interfacial solar heating on soil surface), a commercially available polyethylene film (for vapor condensation and water transport) and a water container, could collect 1.13 kg of clean water per square meter of desert soil per day (8 h), i.e., 0.53 kg of clean water per kilogram of activated carbon per hour, under a solar flux of 0.26-0.55 kW m(2). Besides, the soil water harvesting system is very portable, low-cost and scalable. This work opens up a new sustainable approach for solving the freshwater crisis in arid and impoverished regions. (C) 2021 Elsevier Inc. All rights reserved.

Keywords Plus：SEAWATER DESALINATIONAIR

Published in JOURNAL OF COLLOID AND INTERFACE SCIENCE，Volume 607；10.1016/j.jcis.2021.09.195，FEB 2022