Solvent-Treated Zirconium-Based Nanoporous UiO-66 Metal-Organic Frameworks for Enhanced CO₂ Capture

Metal-organic framework (MOF)-derived nanoscale porous materials are widely deployed in carbon capture, but the CO₂ capacity is varied by different post-treatments, and its mechanism is still unclear. Herein, we prepared UiO-66 and treated it with methanol solvent and thermal activation approaches, which showed ∼3 times enhanced CO₂ capacities from 15.1 to 45.0 mg/g and excellent recyclability of 10 cycles. The methanol treatment efficiently removes the residual guest molecules, including N,N-dimethylformamide, dangling organic linkers, and their derivatives, in the micropores (∼0.8 nm) of UiO-66 and improves the surface area, pore volume, and void fraction to enhance the CO₂ capacity close to the ideal UiO-66 materials. The molecular dynamics simulation also proved a good linear relationship between the surface areas, void fraction, and CO₂ capacity. This work provides a deep understanding of the MOF’s activation mechanism and its applications in CO₂ capture.