Photo-switchable smart metal–organic framework membranes with tunable and enhanced molecular sieving performance. Issue 48 (30th November 2018)

• Record Type: Journal Article
• Authors: Liu, Chuanyao; Jiang, Yunzhe; Zhou, Chen; Caro, Jürgen; Huang, Aisheng
• Is Part Of: Journal of materials chemistry. Volume 6:Issue 48(2018)
• Page Start: 24949
• Page End: 24955
• Publication Date: 2018-11-30
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c8ta10541c
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A novel photo-switchable Cu(AzDC)(4, 4′-BPE)0.5 membrane was developed with the H2 /CO2 separation factor being switched reversibly between 21.3 and 43.7 after irradiation with Vis light (455 nm) and UV (365 nm). Abstract : Developing a novel MOF membrane material with switchable separation performance is an exciting and challenging research project. In the present work, we report preparation of a new kind of light induced smart MOF membrane, i.e., Cu(AzDC)(4, 4′-BPE)0.5 membrane, which shows (i) enhanced molecular sieving performance, and (ii) is able to respond quickly to external light stimuli. Two photo-switchable moieties are addressed in the Cu(AzDC)(4, 4′-BPE)0.5 membrane: azobenzene and bis(4-pyridyl)ethylene. When the Cu(AzDC)(4, 4′-BPE)0.5 membrane is in situ irradiated with Vis and UV light, the separation factor of a H2 /CO2 mixture can be switched reversibly between 21.3 and 43.7. This switching effect is mainly caused by reduced CO2 adsorption in the UV-cis state as proven by independent adsorption studies. For a steric reason, adsorption of CO2 is limited for the UV-cis state. In full agreement with this model, the adsorption of other gases H2, CH4 and N2 as well as their permeation behaviour is not observably influenced by the trans – cis switching.