High‐Efficiency Atmospheric Water Harvesting and Irrigation Recycling in Greenhouse Using Hygroscopic Composite Gels

Abstract The pressing need to address the water‐food nexus, exacerbated by climate change and a rapidly growing population, calls for innovative approaches in agricultural water management. This study introduces a pioneering device, the side window recycler (SWR), which is specifically designed for greenhouses to increase water‐use efficiency. Central to the SWR is a multi‐component, interconnected hygroscopic porous gel named LHPE, which boasts significant scalability and robust adhesion properties. When synthesized through an optimized process, LHPE boasts a high water uptake of up to 4.06 g_water g_sorbent⁻¹, supporting rapid water release during desorption. The SWR utilizes this advanced gel to capture water vapor escaping from greenhouse side windows, converting it into irrigation water through electrically heated desorption. Within greenhouse trials, SWR achieved a water recovery rate of 5015.6 g m⁻² and a water‐saving efficiency of 78.78%, significantly enhancing crop yields by as much as 120%. By integrating sustainable water recycling into agriculture, SWR addresses the global water scarcity crisis and represents a transformative advance in greenhouse water efficiency, poised for impactful adoption in water‐intensive practices worldwide.