Here, carbon materials containing MgO were successfully synthesised using a simple process involving carbonization and microwaveassisted reaction. We have outlined the advantages of the overall procedure from the perspectives of net energy use, synthesis time and simplicity. This work shows that not only the functional groups present but also the porosities of the MgO-modified sorbents affect the CO₂ adsorption behaviours of these MgO/MCs samples. The textural properties and surface chemistry both influenced the CO₂ capture performance of the prepared carbon adsorbents. The results show that the reaction time for MgO loading influenced not only the Mg contents in the final products but also their structures. This suggests that reasonable dispersion of the MgO particles into the carbon materials effectively increases the affinity to CO₂ molecules. From these results, MgO/MCs have potential applications in post-combustion CO₂ capture.