Sandwich-Structured Photothermal Wood for Durable Moisture Harvesting and Pumping

Moisture capture coupled with photothermal regeneration provides an alternative and sustainable way to acquire fresh water. Composite moisture absorbents based on hygroscopic salts are environmentally friendly, economically feasible, and of high efficiency but suffer from the unavoidable desiccant leakage during absorption and evaporation-induced salt accumulation on material surfaces during desorption. In this study, we develop a superhydrophobic-hydrophilic-hydrophobic photothermal wood embedded with CaCl2 to promote the durability of the absorbents. The sandwich structure serves as a liquid/vapor gate allowing vapor transport but forbidding liquid permeation, enabling the condensation and evaporation within the wood. Beyond moisture harvesting, the sandwich-structured photothermal wood exhibits potential in indoor dehumidification by pumping the moisture through an absorption-desorption cycle.

Automated summary

Moisture capture combined with photothermal regeneration offers a sustainable approach to obtaining fresh water. The use of composite moisture absorbents based on hygroscopic salts is effective, but faces challenges such as desiccant leakage and salt accumulation on material surfaces. The development of a superhydrophobic-hydrophilic-hydrophobic photothermal wood embedded with CaCl2 addresses these issues and enables condensation and evaporation within the wood, making it a promising option for moisture harvesting and indoor dehumidification.