A Hydroscopic Indium Hydrogel Capturing Atmospheric Humidity for Autonomous Agriculture

Abstract

The atmospheric water is ubiquitous and abundant, which could be effectively exploited for various applications. However, limited efforts devote to agriculture due to the slowly capture kinetics and highly dehydration temperature. Herein, benefit by a super hygroscopic hydrogel, we integrate a self‐sustainable atmospheric water irrigation system for plant growth at arid land. The hydrogel harvests water from the air during the nighttime, and efficiently releases adsorbed water when the system is exposed to sunlight. The water capture behavior by hydrogel is mainly relying on physisorption, multilayer moistures can be accumulated under weakly Van der Waals force. With the help of hydrophilic surface, the indium hydrogel has a maximum water uptake of up to 5.5 g g−1 at 90% RH. This hydrogel will induce a > 40°C surface temperature under AM 1.5G solar illumination, which is enough for water releasing, making the solar energy driven water‐recycling is possible. At last, the collected water quality meets the international drinking water standard, and then resulting a rapid growth of pea over 6 cm within 8 days.This article is protected by copyright. All rights reserved.