Mesoporous Chitosan–SiO 2 Nanoparticles: Synthesis, Characterization, and CO 2 Adsorption Capacity

Mesoporous chitosan–SiO 2 nanoparticles (NPs) were successfully synthesized. The prepared nanoparticles were characterized using TEM, FTIR, XRD, TGA, EDX, and (CHN) elemental analysis. From TEM micrograph, chitosan–SiO 2 NPs were sphere-like, pretty uniformly distributed with coarse surface. The average size of chitosan–SiO 2 NPs was determined as 211 nm with DLS, which was confirmed by TEM. The mesoporous structure of chitosan–SiO 2 NPs was characterized with N 2 adsorption/desorption measurements. BET surface area was 621 m 2 g –1 and the total pore volume was 0.71 m 3 g –1 . CO 2 adsorption was evaluated by a volumetric method. Chitosan–SiO 2 NPs showed a maximum CO 2 adsorption capacity of 4.39 mmol g –1 at 25 °C and a high selective separation capacity for CO 2 over N 2 ( S CO2/N2 = 15.46). The influence of amines on carbon dioxide adsorption was discussed. Stable CO 2 adsorption/desorption was confirmed after six cycles of experiments. Therefore, chitosan–SiO 2 NPs exhibit great potential for CO 2 capture.