Confined bubbling-assisted preparation of janus-structured eutectogels for sustainable atmospheric water harvesting and microenvironment humidity control

Leveraging hygroscopic sorbents for moisture extraction presents a versatile pathway for atmospheric water harvesting (AWH) and microenvironment humidity control, highlighting the critical need for cost-effective and environmentally friendly production of advanced moisture sorbents. To this end, a facile and green confined-bubbling strategy has been developed for cost-effective fabrication of hygroscopic Janus-structured eutectic gels (JEGs), consisting of a porous body covered by a non-porous layer. This unique structure and composition impart JEGs with large air exposure surfaces and remarkable light-trapping capability, leading to significantly enhanced moisture capture and solar-driven water desorption efficiency compared to conventional eutectic gels. When employed as moisture sorbents in a solar-driven AWH system, JEGs achieve a freshwater production rate of 0.78 L H2O kg JEG3 −1 d −1 during a single harvesting cycle under real-world outdoor conditions. Furthermore, JEGs inherently provide passive microenvironment humidity regulation within the range of 38.8–51.3 % relative humidity, making them ideally suitable for fresh food storage and preservation. The confined-bubbling strategy thus provides an environmentally friendly and cost-effective method for producing Janus-structured eutectic gels, representing a new class of moisture sorbents with significant potential for both AWH and microenvironment regulation applications.