Fluorinated Carbon Nanotube Membranes Are Used for Efficient Anti-Salt Formation Solar Seawater Desalination in High-Salt Environments

The solar-driven interface water evaporation technology shows great potential for application in the field of seawater desalination. However, its practical application still faces persistent challenges: low evaporation rate, salt accumulation leading to performance degradation, and an inability to maintain long-term stable operation at high concentrations. To address these challenges, we designed and fabricated a photothermal membrane, a fluorinated carbon-enhanced porous membrane (F-CEP), which was composed of carbon nanotubes and epoxy and endowed with robust hydrophobicity through surface modification functionalization with perfluoroalkyl silane. This design demonstrated remarkable mechanical qualities (tensile strength: 3.28 MPa), a high capacity to absorb light (250–2500 nm, 97.5%), and the ability to reject salt. After 40 h of exposure to hypersaline brine (20 wt % NaCl), the evaporator maintained salt crystallization-free operation with a sustained vapor flux of 1.95 kg·m –2 ·h –1 under 1-sun irradiation. In contrast, nonfluorinated counterparts (CEP) exhibited substantial surface crystallization (∼2.0 mg/cm 2 ) within 10 h. This study demonstrated a viable solution for sustained high-throughput evaporation during prolonged operation in high-salinity environments through the synergistic effects of surface hydrophobic modification and structural design, showcasing its significant potential for application in seawater desalination.