MXene assisted preparation of well-intergrown ZIF-67 membrane for helium separation

• Published in: Journal of membrane science 2022-06, Vol.652, p.120432, Article 120432
• Main Authors: Zhao, Zhijun, Ding, Li, Hinterding, Richard, Mundstock, Alexander, Belke, Christopher, Haug, Rolf J., Wang, Haihui, Feldhoff, Armin
• Format: Article
• Language: English
• Subjects: 2D laminar membrane; carbon dioxide; Gas separation; helium; Helium recovery; MXene; permeability; ZIF-67 membrane
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2022.120432

Well-intergrown ZIF-67 membranes were prepared by the assistance of laminarly stacked MXene films. Several analytic methods have found that the MXene films, despite being as thin as 90 nm, could host a high amount of Co (II) ions. The Co (II)-MXene films acted as buffer layer and provided anchor sites for nucleation. After solvothermal synthesis, well-intergrown ZIF-67 membranes with a thickness about 4 μm were formed on Co (II)-MXene modified α-Al2O3 disks. Single-gas and mixed-gas permeation experiments showed that the ZIF-67 membranes exhibited excellent gas separation performance and long-term chemical (against CO2 and H2O) and thermal stabilities with a He permeance greater than 6.6 × 10−8 mol m–2 s–1 Pa–1 and selectivities above 13 for the gas mixtures He/N2 and He/CH4, superior to the state-of-the-art MOF membranes. [Display omitted] •Cobalt ions are absorbed and intercalated into a 90 nm thick MXene film.•Co (II)-MXene films promote heterogeneous nucleation of ZIF-67.•Well-intergrown ZIF-67 membranes are prepared on MXene covered Al2O3 supports.•MXene assisted ZIF-67 membranes exhibit excellent helium separation performance.