Self-catalyzed strategy to form hollow carbon nanospheres for CO2 capture

Abstract The hollow carbon nanospheres (HCNs) are synthesized by self-catalyzed method. The amino-functionalized silica nanospheres (NH 2 –SiO 2 ) play the roles of template and catalyst. As a basic group, the amino provides slight alkaline conditions which can catalyze the polymerization of resorcinol-formaldehyde (RF) resin. Additionally, the amino group covering the outer surface of SiO 2 turns to be slight positively charged in the solution, which allows deposition of negatively charged RF on the surface of NH 2 –SiO 2 . The method has an advantage over previous method in terms of environment protection due to the absence of surfactant and ammonia. After carbonization and removal of the SiO 2 templates, the obtained HCNs completely copy the morphology of SiO 2 , exhibiting uniform and monodispersed spherical structures with the diameter of ~290 nm and surface area of 777 m 2 g −1 . The sample exhibits a performance for CO 2 capture with the capacity of 3.65 mmol g −1 at 298 K and 1.0 bar after activation with KOH.