MIL-101 is a highly porous metal-organic framework (MOF) used to capture (adsorb) CO₂. MIL-101 MOFs incorporating amine moieties are often used to extract CO₂ from ultra-dilute mixtures such as ambient air. Typically, these materials are used for adsorption at higher temperatures and/or concentrations, such as with flue gas (combustion exhaust) at power plants or other industrial activities. However, there is no evidence of the use of these MIL-101/amine materials for CO₂ adsorption at temperatures below typical indoor, room temperatures of ~20 °C. Using MIL-101/amine hybrid materials, Georgia Tech researchers have been able to capture CO₂ from simulated air at temperatures of -20 to 25 °C (-4 to 77 °F), with and without humidity. The research has shown high CO₂ uptake selectivity versus nitrogen, and that by tuning the composition of the hybrid or the amine used [branched poly(ethyleneimine) (PEI), tetraethylenepentamine (TEPA), etc.], the strength of CO₂ adsorption and the corresponding CO₂ desorption temperature can be tuned. The MIL-101/amine materials are tested as powders, incorporated into polymeric fibers or composite monoliths. Small temperature swings can be achieved, including desorption near ambient indoor conditions (room temperature).