Dual‐tuning azole‐based ionic liquids for reversible CO2 capture from ambient air

Abstract A strategy of tuning azole‐based ionic liquids for reversible CO 2 capture from ambient air was reported. Through tuning the basicity of anion as well as the type of cation, an ideal azole‐based ionic liquid with both high CO 2 capacity and excellent stability was synthesized, which exhibited a highest single‐component isotherm uptake of 2.17 mmol/g at the atmospheric CO 2 concentration of 0.4 mbar at 30 °C, even in the presence of water. The bound CO 2 can be released by relatively mild heating of the IL‐CO 2 at 80 °C, which makes it promising for energy‐efficient CO 2 desorption and sorbent regeneration, leading to excellent reversibility. To the best of our knowledge, these azole‐based ionic liquids are superior to other adsorbent materials for direct air capture due to their dual‐tunable properties and high CO 2 capture efficiency, offering a new prospect for efficient and reversible direct air capture technologies.