Novel Ramie Fabric-Based Draping Evaporator for Tunable Water Supply and Highly Efficient Solar Desalination

Interfacial solar-driven evaporation is a promising path to address the scarcity of freshwater. Lots of efforts have been made to develop highly efficient photothermal materials and optimize operational efficiency. However, the designed solar evaporator tends to directly contact with seawater, leading to inevitable parasitic heat loss and the total suppression of evaporation of the backside. Here, we show a novel draping fabric system by separating the evaporation interface from bulk water. The evaporation area was exposed to air with enhanced natural convection and double-side evaporation. The draping fabric was prepared by coating the mixture of carbon black (CB) and cross-linked sodium alginate (SA) on ramie fabric (CSRF). The draping CSRF realized an evaporation rate of 1.81 kg m–2 h–1 and efficiency of 96.6% under 1 sun illumination (1 kW m–2). In addition, by changing the yarn fineness of the fabric, a tunable water supply can be realized to optimize the energy distribution. This work provides a new strategy to design and optimize the solar evaporation system, exhibiting great potential in real-world applications.