The utilization of Mg−O−F prepared from Mg(OH) 2 mixed with different wt % of F in the form of (NH 4 F•HF), calcined at 400 and 500 °C, for efficient capture of CO 2 is studied herein in a dynamic mode. Two different temperatures were applied using a slow rate of 20 mL•min −1 (100%) of CO 2 passing through each sample for only 1 h. Using the thermogravimetry (TG)-temperature-programed desorption (TPD) technique, the captured amounts of CO 2 at 5 °C were determined to be in the range of (39.6−103.9) and (28.9−82.1) mg COd 2 •g −1 for samples of Mg(OH) 2 mixed with 20−50% F and calcined at 400 and 500 °C, respectively, whereas, at 30 °C, the capacity of CO 2 captured is slightly decreased to be in the range of (32.2−89.4) and (20.9− 55.5) mg COd 2 •g −1 , respectively. The thermal decomposition of all prepared mixtures herein was examined by TG analysis. The obtained samples calcined at 400 and 500 °C were characterized by X-ray diffraction and surface area and porosity measurements. The total number of surface basic sites and their distribution over all samples was demonstrated using TG-and differential scanning calorimetry-TPD techniques using pyrrole as a probe molecule. Values of (ΔH) enthalpy changes corresponding to the desorption steps of CO 2 were calculated for the most active adsorbent in this study, that is, Mg(OH) 2 + 20% F, at 400 and 500 °C. This study's findings will inspire the simple preparation and economical design of nanocomposite CO 2 sorbents for climate change mitigation under ambient conditions.