Shiyu Fu, Xiaoling Kang, Huimin Wang, Zheng Wang, Binjie Li, Jiang Gong*, Xu Peng*, Zhiyue Dong*

Highly stable MOF-based dual-functional membranes for solar steam evaporation and oil-water separation

Chemical Engineering Journal (2026) (IF2025 = 13.2) Accept.

In the face of the global water crisis, seawater desalination and sewage treatment represent excellent countermeasures. For sewage treatment, the ideal approach is to achieve rapid evaporation of water molecules and simultaneous separation of oil contaminants from water bodies. So the dual-functional materials have been urgently developed to meet the integrated application demands in complex scenarios. This study proposes a novel integrated design strategy of "one membrane for dual applications". A ternary synergistic mixed-matrix composite membrane (MCxPy) composed of MOF-801/carbon nanotubes (CNTs)@poly(ionic liquid) was successfully constructed on a polyvinylidene fluoride (PVDF) substrate. The micropores and mesopores of MOF-801 and CNTs form the interconnected water/steam transport channels and promote bulk water into water clusters. It effectively lowers down water's vaporization enthalpy and raises its evaporation rate, which has been verified by molecular dynamics (MD) and DSC test. Consequently, the material acts as efficient "artificial leaves" in solar-driven interfacial evaporation, enabling high-rate water evaporation (2.6 kg·m^-2·h^-1) and energy conversion (50.7%) efficiency. The evaporation rate could remain almost unchanged within 20 h with almost unchanged energy efficiency. And it functions as smart "molecular sieves", achieving high emulsion flux (0.015 L·m^-2·h^-1·Pa^-1) and high selectivity separation (95.5%) through hydrophilic networks and precise pore structures in oil-water separation systems. The MCxPy membranes maintain excellent structural stability in a wide range of aqueous solutions with pH 1 to 13, fully demonstrating that it possesses favorable environmental adaptability and can be applied to sewage treatment in various complex acid-base environments. This work not only provides a controllable fabrication paradigm for multifunctional membrane materials but also demonstrates the great potential of a single material platform to adapt to multiple application scenarios via the design of structure, offering a new material perspective for addressing complex water environment issues.