A durable MOF-303-coated stainless steel mesh with robust anti-oil-fouling performance for multifunctional oil/water separation

Abstract

Durable anti-fouling membranes for the effective and simultaneous removal of insoluble oil droplets and organic dyes from wastewater need to be developed urgently. Metal–organic frameworks (MOFs) are emergent porous organic–inorganic hybrid materials, that have been attracting increasing attention because of wide applications, such as liquid separation, dye adsorption, and catalysis. However, the preparation of a well-intergrown MOF membrane remains challenging, because of poor water stability and low affinity between MOF grains and substrates. Herein, we report the first preparation of a continuous, water-stable MOF-coated mesh with an ordered porous structure by using a simple hydrothermal method to realize array growth of MOF-303 crystals on a layered double-hydroxide modified mesh surface. As the MOF-303 has a high water uptake capability, the prepared MOF-303 @SSM with sufficient surface hydration exhibited superhydrophilicity-underwater superoleophobicity and excellent antifouling performance. This membrane was used for gravity-driven separation of oil/water mixtures at high flux (> 12308 L m−2 h−1) and efficiency (> 99.35%). This membrane simultaneously and efficiently removed an oil-in-water (O/W) emulsion and water-soluble dyes, and exhibited outstanding reusability. More importantly, MOF-303 @SSM is promising for practical applications because of outstanding physical and chemical stability, as well as high thermal stability, under harsh environmental conditions. Therefore, this study provides a promising strategy to develop a functional MOF membrane for purifying hazardous wastewater.