A Nature-Inspired Monolithic Integrated Cellulose Aerogel-Based Evaporator for Efficient Solar Desalination

Abstract

Solar-driven seawater desalination is a prospective approach to tackle the problem of freshwater shortage. Establishing a robust, efficient solar-thermal water evaporator with great salt-resistance through a facile and scalable fabrication technique is still a challenge. In this study, a floatable and robust monolithic integrated cellulose aerogel-based evaporator (MiCAE) with high performance is fabricated by carefully designing and integrating three functional components, namely, a hydrophilic cellulose-PVA aerogel (CPA), hydrophobic silylated cellulose aerogel (SCA), and multiwalled carbon nanotube (MCNT) coating layer (CPA@CNT), through the heterogeneous mixing and freeze-drying aerogel fabrication step in situ. Inspired by woods and mushrooms, the incorporation of SCA with mushroom-shaped CPA possessing wood-like structures in MiCAE can realize heat localization and effectively suppress irreversible heat dissipation. Meanwhile, CPA endows the evaporator with the rapid water transportation and great salt excretion capability because of its low-tortuosity porous structure. Thanks to the synergistic effect of the integrated functional structures, in the highly concentrated brine (17.5 wt %), the MiCAE can still realize the combination of high efficiency and obvious salt-resistance behavior. This work offers a facile, efficient salt-resistance solution for seawater desalination.