Energy Efficient Ultrahigh Flux Separation of Oily Pollutants from Water with Superhydrophilic Nanoscale Metal-Organic Framework Architectures

Mähringer, Andre; Hennemann, Matthias; Clark, Timothy; Bein, Thomas and Medina, Dana D. (2021): Energy Efficient Ultrahigh Flux Separation of Oily Pollutants from Water with Superhydrophilic Nanoscale Metal-Organic Framework Architectures. In: Angewandte Chemie-International Edition, Vol. 60, No. 10: pp. 5519-5526

Abstract

The rising demand for clean water for a growing and increasingly urban global population is one of the most urgent issues of our time. Here, we introduce the synthesis of a unique nanoscale architecture of pillar-like Co-CAT-1 metal-organic framework (MOF) crystallites on gold-coated woven stainless steel meshes with large, 50 mu m apertures. These nanostructured mesh surfaces feature superhydrophilic and underwater superoleophobic wetting properties, allowing for gravity-driven, highly efficient oil-water separation featuring water fluxes of up to nearly one million L m(-2) h(-1). Water physisorption experiments reveal the hydrophilic nature of Co-CAT-1 with a total water vapor uptake at room temperature of 470 cm(3) g(-1). Semiempirical molecular orbital calculations shed light on water affinity of the inner and outer pore surfaces. The MOF-based membranes enable high separation efficiencies for a number of liquids tested, including the notorious water pollutant, crude oil, affording chemical oxygen demand (COD) concentrations below 25 mg L-1 of the effluent. Our results demonstrate the great impact of suitable nanoscale surface architectures as a means of encoding on-surface extreme wetting properties, yielding energy-efficient water-selective large-aperture membranes.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 1433-7851
• Language: English