N-doped monodisperse carbon nanospheres with high surface area for highly efficient CO2 capture

Abstract

Carbon nanospheres are attractive materials with great potentials in many applications. Herein, we presented the synthesis and CO2 capture of N-doped monodisperse carbon nanospheres with high surface area. Spherical 3-aminophenol-formaldehyde resin with uniform size and shape was used as the precursor, which was then converted into carbon nanospheres through KHCO3 activation. KHCO3 activation was the key to the synthesis of carbon spheres, because it led to the formation of highly porous structure with surface area up to 3096 m2/g, and perfectly preserved the spherical shape at the same time. In contrast, the spherical structure was completely destroyed during KOH activation. The carbon nanospheres also showed high nitrogen content of 2.54–8.54 wt%. CO2 adsorption performances of the carbon nanospheres were studied with pressure up to 20 bar. The carbons showed impressively high uptakes of 31.42/21.55 mmol/g at 0/25 °C and 20 bar, which outperformed many reported results under the same conditions. The correlation between CO2 adsorption performances and physicochemical properties at different pressures were studied and revealed.