Synthesis of carbon spheres by atmospheric pressure chemical vapor deposition from a serial of aromatic hydrocarbon precursors

Uniform shaped carbon spheres, a material with several potential applications, were synthesized from a serial of aromatic hydrocarbon pyrolysis precursors (benzene, naphthalene, anthracene and pyrene), by chemical vapor deposition at atmospheric pressure, and at moderately low temperatures with stainless steel catalyst. A high carbon sphere yield, without secondary products, was achieved at temperatures above 850 degrees C. Sphere diameters decrease, in some cases, according to the temperature increments. Field emission scanning electron microscopy images show a completely solid core. Raman and Fourier transform infrared spectra suggest a larger amount of CHx bonds on the sphere surface with major curvature. Spheres are formed by small crystalline graphene flakes, observed by high resolution transmission electron microscopy and confirmed by the G band intensity in Raman spectra and X-ray diffraction signals.