Hyperstable and compressible plant fibers/chitosan aerogel as portable solar evaporator

• Develop a portable solar evaporator that can save storage space more than 78%. • Hyperstable plant fibers/chitosan aerogel is constructed without toxic cross-linkers/solvents. • The solar evaporator can endure tremendous and repeated compression over 100 times. • The evaporator is cost-effective and salt-rejecting, working well under various harsh conditions. • High evaporation rate of 1.38 kg m -2 h −1 and solar-to-vapor conversion efficiency of 84.27%. Solar interfacial evaporation is an effective zero-energy method for seawater desalination, and solar evaporator is the key component in this evaporation system. Despite a great deal of solar evaporators have been reported, the poor portability of large-scale evaporators as well as high costs and materials toxicity still restrict their applications. In this work, a portable solar evaporator was constructed with low-cost plant fibers from papermaking pulp, using a facile method in absence of any toxic cross-linkers and solvents. The evaporator exhibited excellent stability and flexibility, and endured tremendous and repeated compression over 100 times. A large-scale evaporator could be compressed to reduce storage space by 78%, which would be portable for individuals. The evaporator presented a high evaporation rate of 1.38 kg m -2 h −1 , and solar-to-vapour conversion efficiency of 84.27% under one sun irradiation. The portable solar evaporator was salt-rejecting, and worked well under harsh conditions of high salinity and different pH values. The entire material cost of this potable solar evaporator is approximately 1.75 U.S. dollar m −2 , much lower than those of conventional solar evaporators. This study provides a new approach for preparing portable and cost-effective solar evaporator.