Facile Fabrication of Multifunctional Metal–Organic Framework Hollow Tubes To Trap Pollutants

Pollutant treatment is critical in modern society and often requires tedious workup and expensive facilities. By virtue of structural diversity and tunability, metal-organic frameworks (MOFs) have shown promise in pollutant control. We herein report a powerful templated freeze-drying protocol for the fabrication of multifunctional MOF hollow tubular structures for both air and liquid contaminants filtration. Various hollow tube systems (e.g., "Janus", "coaxial" and "cellular") are produced. Specially, a multilayer coaxial MOF hollow tube is prepared for highly efficient capture of mixed inorganic-organic liquid contaminants with >94% filtration efficiency. Further, a "cellular" hollow tube with low pressure-drop (12 Pa, 10 cm s^-1) is applied in particulate matter filtration with high efficiency (>92%). Given the rich structural and functional diversities, this protocol might bring MOFs into industrial applications to remediate environmental problems.