Zhang Baoping, Wong Pak Wai, Guo Jiaxin, Zhou Yongsen, Wang Yang, Sun Jiawei, Jiang Mengnan, Wang Zuankai, An Alicia Kyoungjin
School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue Kowloon, Hong Kong, Hong Kong.
Department of Mechanical Engineering, City University of Hong Kong, Tat Chee Avenue Kowloon, Hong Kong, Hong Kong.
Nat Commun. 2022 Jun 8;13(1):3315. doi: 10.1038/s41467-022-31028-6.
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 (∆T) and excellent membrane durability. However, it's difficult to maintain constant ∆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 TiCT 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 TiCT 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.
由于其100%的理论脱盐能力，膜蒸馏（MD）已成为一种有前景的海水淡化方法，以解决淡水短缺问题。理想的膜蒸馏需要通过跨膜温度梯度（∆T）建立高蒸汽渗透通量以及优异的膜耐久性。然而，由于连续的水-汽转变导致进水侧存在固有热损失，因此难以维持恒定的∆T，并且难以防止润湿转变引起的膜污染和结垢。在此，我们开发了一种由TiCT MXene设计的膜，该膜具有高效的局部光热效应和强疏水性，从而显著提高了淡水生产率和稳定性。除了规避热损失的光热效应外，高导电性的TiCT MXene还允许通过静电喷涂在其表面自组装均匀的分级聚合物纳米球，将固有亲水性转变为超疏水性。这种界面工程实现了在一个太阳辐照下具有高产水率的节能且超盐稳定的光热膜蒸馏。
