Controllable synthesis of nitrogen-doped hollow carbon nanospheres with dopamine as precursor for CO2 capture

Nitrogen-doped hollow carbon nanospheres (N-HCSs) have been synthesized by self-polymerization of dopamine on silica spheres using the modified Stober method. The fabrication process uses dopamine as carbon and nitrogen source and tetraethyl orthosilicate as a structure-assisting agent. The particle sizes and shell thicknesses of the N-HCSs can be easily tuned in the range of 270–700 nm and 30–55 nm, respectively, by simply modifying the ethanol/water volume ratios. The surface areas of N-HCSs are in the range of 345–463 m2 g−1, and the total pore volumes are in the range of 0.34–0.52 cm3 g−1. The obtained N-HCSs have uniform mesoporous size of ∼4.0 nm, and high nitrogen loading content of 7.2 at%. Besides, the N-HCSs exhibit a considerable performance for CO2 capture with a capacity of 3.09 mmol g−1 at 25 °C and 1.0 bar and a good cycling stability.