Bioinspired magnetically generated bilayer aerogel with vertically aligned pores: Efficient solar evaporation and water purification for crop production

Abstract

Facing the challenge of freshwater scarcity, solar evaporation technology with interfacial heating is considered to be a technology that uses solar energy to sustainably obtain fresh water through evaporation and condensation processes. However, the construction of a solar-driven evaporation system capable of consistently, efficiently, and steadily producing pure water under sunlight is pivotal yet challenging. In this work, inspired by mushrooms, a magnetic-generated double‑layered solar evaporator is designed for efficient water evaporation. With the thermal management of the aerogel and the vertical arrangement of the water channels, this evaporator overcomes the trade-off between water delivery and heat management that has long plagued traditional evaporators. In addition, the presence of cold evaporation breaks the long-existing photothermal efficiency of traditional solar evaporation cannot exceed the limit of 100 %. With this structure, an evaporation rate of 1.966 kg m−2 h−1 and a solar-to-vapor energy efficiency of 120.6 % are achieved under irradiation of 1 sun. The mung beans are irrigated with pure water obtained by evaporation to germination. The work provides a new direction for manufacturing evaporators and key insights into addressing water scarcity and the use of water.