With carbon emissions increasing rapidly, it is vital to develop new ways to remove carbon dioxide from the atmosphere. Membrane‐based CO2 capture offers an energy‑efficient route to decarbonize industrial emissions, but polymer membranes often face permeability-selectivity tradeoffs. This study focuses on the addition of Ti3C2Tx MXene nanosheets to supported ionic liquid membranes (SILMs) containing Pebax® 2533 and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid. Using the greener casting solvent Rhodiasolv PolarClean, we fabricated uniform thin films and quantified equilibrium CO2 sorption via quartz crystal microbalance (QCM) gravimetry, using the Sauerbrey equation. To achieve homogeneous MXene distribution within the membrane, sonication and mixing conditions were optimized. Incorporating 20 wt.% MXene increased CO2 solubility relative to MXene free Pebax/ IL controls. Specifically, at 10 °C and 200 psi, solubility increased from 2.74 ± 0.04 to 2.92 ± 0.08 mol CO2 kg-1 IL (6.6% increase). The enhancement can be attributed to MXene’s abundant polar surface groups that strengthen CO2 affinity, improved IL dispersion and microstructural stability within the polymer, and MXene induced increases in fractional free volume that provide additional sorption space. These results demonstrate a simple, greener processing pathway to synergistically combine a CO2 philic polymer, ionic liquid, and 2D filler, yielding robust membranes with measurably higher CO2 uptake.
