Facile Synthesis of MgO-Modified Carbon Adsorbents with Microwave-Assisted Methods: Effect of MgO Particles and Porosities on CO2 Capture

In this study, magnesium oxide (MgO)-modified carbon adsorbents were fabricated using a nitrogenenriched carbon precursor by microwave-assisted irradiation for CO2 capture. The X-ray diffraction (XRD) patterns showed the characteristic diffraction peaks of MgO at 43 degrees and 62.5 degrees, and no impurities were apparent. By changing the microwave reaction time, the spherical structure of the parent material was transformed to a hybrid structure with MgO crystalline particles in a carbon matrix. The morphology evolution and properties of the prepared materials were also investigated using transmission electron microscopy and N-2 adsorption, respectively. On optimising the conditions, the prepared sample attained a high CO2 uptake of 1.22 mmol/g (5.3 wt.%) under flue gas conditions (15% CO2 in N-2). It was found that MgO affected the CO2 capture behaviour by enhancing the fundamental characteristics of the carbon surfaces.