Preparation and characterization of porous carbon spheres with controlled micropores and mesopores

Porous carbon spheres were prepared by interfacial sol–gel polymerization. The microstructure of the carbon spheres is investigated by SAXS, TEM, and FE-SEM. The framework of resulting carbon sphere is hollow structure with a cavity of about 200 nm diameter. The structure of hollow carbon sphere wall is mesopores with average pore diameter of 5–26 nm, porosity of 0.52–0.91, and specific surface of 210–670 m2/cm3 and 747–1606 m2/g. The pore characteristic of the hollow carbon spheres varies with different carbon source concentration. The carbon spheres whose precursor solution concentration is 52 wt%, have the highest specific surface area of 1606 m2/g. Cryogenic hydrogen sorption capacity was determined at 77 K, and hydrogen uptake of 2.37 wt% was achieved for the porous carbon spheres.

Research highlights▶ Porous carbon spheres were prepared by interfacial sol–gel polymerization. ▶ Carbon sphere has a cavity and a carbon wall filled with mesopores. ▶ The pore structure of carbon spheres varies with different carbon source concentration. ▶ CO2-activation further improves the network structure of the carbon spheres.