A Moisture‐Hungry Copper Complex Harvesting Air Moisture for Potable Water and Autonomous Urban Agriculture

The earth's atmosphere houses an enormous amount of water, which could be effectively exploited for a plethora of applications. While the development of materials for harnessing this abundant resource has gained impetus in recent years, limited efforts have been devoted to in‐depth research on their agricultural applications. Herein, a novel copper(II)–ethanolamine complex (Cu‐complex), which has a maximum water uptake of up to 300% and a water production rate of 2.24 g g−1 h−1 under natural sunlight, is reported. As a proof‐of‐concept application, using this material, a fully automated and self‐sustainable solar‐powered SmartFarm device is developed. The Cu‐complex harvests atmospheric water during the night, stores the adsorbed water within, and efficiently releases the adsorbed water during the day when the device is exposed to sunlight. The water harvesting and irrigation process can be fine‐tuned to suit different types of plants and local climates for an optimal cultivation. With the SmartFarm in operation, the demand for freshwater for irrigation could be greatly reduced and urban farming techniques such as large‐scale rooftop farming could be promoted with a view of alleviating both water and food scarcity in the near future. A moisture‐hungry Cu‐complex is synthesized and used for fabricating a SmartFarm device that can harvest atmospheric water during the nighttime and release water during the daytime under natural sunlight. The device enables self‐sustainable and autonomous irrigation to alleviate both water and food scarcity.