Tuning surface polarity and topography in Ti₃C₂T_x-integrated nanofibrous membranes for enhanced water desalination

Membrane distillation (MD) has emerged as a promising desalination technology owing to its potential for nearly 100 % salt rejection, yet its adoption is impeded by membrane fragility and wetting. Here, we present a breakthrough in electrospun membrane technology by integrating spatially confined MXene (Ti₃C₂T_x) nanosheets into a polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) nanofibrous matrix. This pioneering approach significantly enhances membrane hydrophobicity, mechanical robustness and vapor flux. The electrostatic interactions and hydrogen bonding between MXene and the polymer matrix induced favorable alignment of –CH₂−/−CF₂– dipoles, reducing surface energy and increasing hydrophobicity. Additionally, MXene-induced surface roughness promoted air pocket formation, further minimizing wettability. A thorough investigation was conducted to assess the influence of MXene loading on fiber morphology, wettability, and MD performance. Our optimized membranes demonstrated stable performance for over 60 h using real seawater in both air gap and water gap MD configurations. This work provides clear pathways to next-generation desalination membranes, harnessing two-dimensional nanomaterials to solve pressing global water challenges.