Preparation of washable and salt-resistant composites for continues solar-driven evaporation and seawater desalination based on ES nonwovens

Abstract

Solar-powered interfacial evaporation is a novel and eco-friendly technology for producing fresh water from seawater. However, current interfacial evaporators are expensive to manufacture, have poor tolerance for environmental conditions, and struggle to achieve stable evaporation in highly saline solutions while also preventing salt accumulation. Therefore, the fabrication of user-friendly, long-lasting, and salt-resistant interfacial evaporators remains a significant challenge. In this study, an efficient and durable interfacial evaporator was fabricated by embedding hydroxyl dobby carbon nanotubes (CNTs) and polydopamine (PDA) onto ES nonwoven fabrics. The prepared PDA-CNT-ES (PCES) composite-evaporator exhibited excellent light absorption and hydrophilic properties, which can be attributed to the light absorption capabilities of carbon nanotubes and the hydrophilicity of PDA. The combination of CNTs and PDA coatings produced a synergistic effect, leading to an efficient photothermal performance of the evaporator surface, which resulted in a significant evaporation rate of 1.29 kg⋅m−2⋅h−1 and a solar thermal efficiency of 90.77% under 1.0 solar irradiation (1 kW⋅m−2). The PCES composites, in particular, demonstrated effective purification under various simulated seawater conditions, and the desalinated water produced met the standards for potable water. The composites exhibited remarkable durability and stability over 10 desalination cycles. These results provide new insights for applying these findings in seawater desalination and wastewater treatment.