MXene-based flexible and washable photothermal fabrics for efficiently continuous solar-driven evaporation and desalination of seawater

Solar-driven interface evaporation (SDIE) is a promising seawater desalination technology, which can achieve long-term and efficient seawater desalination in laboratory. However, because of fragile and easily damaged, the solar absorbers are difficult to be applied in the complex and changeable actual applications. In this work, a polypyrrole/Ti3C2Tx MXene-polydopamine-fabric (PPy/MXene-PDA-fabric) was prepared by a simple two-step polymerization method in this study, which can be used as the solar absorber of the SDIE system. Due to the unique physical properties of elastic fabrics, the PPy/MXene-PDA-fabric is easy to transport and clean, making it extremely practical. Meanwhile, the combination of polypyrrole, polydopamine, and MXene photothermal materials also ensures its excellent photothermal conversion performance. The research results show that the average evaporation rate of PPy/MXene-PDA-fabric can reach 1.485 kg/m2h in nearly 100 h of evaporation test under one sun irradiation. After 12 h of continuous operation, only a tiny amount of salt accumulated on the surface of the sample, which could be continued after a simple cleaning. The evaporation rate remained stable after eight cycles. Compared with the traditional solar absorber, PPy/MXene-PDA-fabric not only ensures efficient and durable solar evaporation performance, but also dramatically improves the practicability and environmental applicability.