Carbon Powders Prepared by Ultrasonic Spray Pyrolysis of Substituted Alkali Benzoates†

Ultrasonic spray pyrolysis (USP) has been used to prepare carbon spheres from aqueous solutions of substituted alkali benzoate salts. The size of the carbon spheres produced during USP can easily be controlled simply by changing the concentration of the precursor solution. Both the cation and the ring substituents of a given precursor influence product morphology, which ranges from solid spheres to hollow bowls to porous spheres. Thermogravimetic analysis of the various precursors suggests that the relative temperature of decomposition steps releasing gas explain these observed morphology differences