Transforming Ti3C2Tx MXene's intrinsic hydrophilicity into superhydrophobicity for efficient photothermal membrane desalination

作者：Zhang, Baoping; Wong, Pak Wai; Guo, Jiaxin; Zhou, Yongsen; Wang, Yang; Sun, Jiawei; Jiang, Mengnan; Wang, Zuankai^*; An, Alicia Kyoungjin^*

来源：Nature Communications, 2022, 13(1): 3315.

DOI：10.1038/s41467-022-31028-6

• SEAWATER DESALINATION
• SCALING RESISTANCE
• SOLAR
• DISTILLATION
• STABILITY
• ENERGY

Membrane distillation is susceptible to thermal inefficiency and membrane wetting issues during seawater desalination. Here, authors design a MXene-engineered membrane that imparts efficient localized photothermal effect and strong water repellency, achieving sustainable freshwater production. @@@ Owing to its 100% theoretical salt rejection capability, membrane distillation (MD) has emerged as a promising seawater desalination approach to address freshwater scarcity. Ideal MD requires high vapor permeate flux established by cross-membrane temperature gradient ( increment T) and excellent membrane durability. However, it's difficult to maintain constant increment T owing to inherent heat loss at feedwater side resulting from continuous water-to-vapor transition and prevent wetting transition-induced membrane fouling and scaling. Here, we develop a Ti3C2Tx MXene-engineered membrane that imparts efficient localized photothermal effect and strong water-repellency, achieving significant boost in freshwater production rate and stability. In addition to photothermal effect that circumvents heat loss, high electrically conductive Ti3C2Tx MXene also allows for self-assembly of uniform hierarchical polymeric nanospheres on its surface via electrostatic spraying, transforming intrinsic hydrophilicity into superhydrophobicity. This interfacial engineering renders energy-efficient and hypersaline-stable photothermal membrane distillation with a high water production rate under one sun irradiation.