Synthesis of submicron carbon spheres by the ultrasonic spray pyrolysis method

Submicron carbon spherical particles were obtained by polycondensation of resorcinol and formaldehyde in a solution and subsequent ultrasonic spray pyrolysis of the prepared sol. Microscopic characterization indicates the regular spherical shape of the obtained particles and sphere diameters in 200-700 nm range. The carbon spheres are amorphous as confirmed by electron diffraction, EELS, XRD and HREM characterization. Activation procedure was performed with H₂O in a nitrogen flow for 15 and 30 min at 800 °C. The activation procedure preserved the initial spherical shapes of the particles while the particle porosity and specific surface area were increased. The amount of surface oxygen functionalities was also increased by activation procedure as indicated by FTIR analysis.