Flexible metal-organic framework films for reversible low-pressure carbon capture and release.

Transitioning metal-organic frameworks (MOFs) from laboratory-scale to carbon dioxide (CO) capture and storage applications (CCS) requires in-depth understanding of their adsorption properties and structural stability, especially for film assemblies. However, evaluating their performance is challenging, particularly under low or moderate CO pressure conditions, which are key for cost and performance efficiency. Herein, we explore the low-pressure CO uptake and release within flexible Zn-based MOF film structures with diverse ligand functionalities, employing quartz crystal microbalance, synchrotron radiation-based infrared spectromicroscopy and grazing incidence wide-angle X-ray scattering measurements. To investigate CO adsorption and its interaction with Zn-MOF pores, we exploited the framework's flexibility by triggering structural changes and thus variations of the pore-environment using two stimuli, temperature and light. Results show considerable promise for stimuli-induced on-demand CO capture and release at low pressures, demonstrating structural reversibility under near-ambient conditions and highlighting the potential of tailored MOF film structures in advancing green CCS-technologies.