Architecting the Water State of Polypyrrole/Polyvinyl Alochol‐Wood Evaporator to Enhance Water Yield in Multistage Solar Stiller

Abstract

Solar desalination is one of the most promising ways to produce freshwater. Interfacial solar steam generation system is especially studied for its high solar–thermal conversion efficiency. However, the phase transition process of water evaporation is energy intensive and a salt cluster is easily accumulated at the surface of the evaporator, which limits the water yield and stability of the distiller. Herein, a hybrid design involving tuning the water state, recycling latent heat, and spatial localizing low‐concentration zone to distill for stable and efficient solar‐water harvesting is demonstrated. In a two‐stage distiller, the water yield can reach 1.62 kg m−2 h−1 under one sun irradiation, corresponding to the solar‐to‐vapor conversion efficiency of 110%. The scale‐up device can also steadily operate for 1 week outdoors. This work provides an effective strategy for high‐efficiency solar distillation, holding the promise of application in seawater desalination and domestic water supply.