Scalable, Flexible, Durable, and Salt-Tolerant CuS/Bacterial Cellulose Gel Membranes for Efficient Interfacial Solar Evaporation
Dong Zhang, Yixiao Cai, Qianqian Liang, Zhuotong Wu, Nan Sheng, Minghao Zhang, Baoxiu Wang, Shiyan Chen
Abstract
Solar-driven photothermal conversion devices are currently highly investigated in seawater evaporation and desalination applications. However, considering cases in small portable household outfits, it remains a considerable challenge to develop a scalable low-cost system with practically stable evaporation and salt-resistant performance. Herein, we demonstrate an inexpensive bilayered evaporation system, utilizing CuS/bacterial cellulose (BC) hybrid gel membranes as a photothermal conversion layer via an in situ synthetic route and BC-wrapped polyethylene foam as a water transport and heat insulation layer. The optimized evaporation rate reached 1.79 kg m–2 h–1 under 1 kW m–2 and the efficiency reached 98.5%, which is comparable to the best performance for BC-based composites that have been reported so far. The evaporation rate remained stable after 40 cycles, which suggests excellent cyclability of prepared gel membranes. More significantly, the bilayered evaporator also reveals excellent salt-resistant performance of more than 12 h and a stable evaporation rate. The excellent property was attributed to the effective heat localization from the upper CuS/BC layer, while the bottom BC layer secured adequate water supply and transport. We also examined the flexibility and portability of these membranes, showing their practical value for a variety of portable household water technologies.