Synthesis and properties of carbon nanospheres grown by CVD using Kaolin supported transition metal catalysts

Carbon spheres with diameters between 400 and 2000 nm were synthesized in large quantities by catalytic chemical vapor deposition (CCVD) method using Kaolin supported transition metal salts (M ¼ Fe, Co, Ni, etc.) as catalysts. The reaction conditions for the synthesis of carbon spheres in different sizes are described. The reactivity of the carbon spheres in various organic solvents is discussed. The as-synthesized carbon spheres are composed of unclosed graphene layers with the interlayer distances 0.33–0.35 nm. These carbon spheres have been characterized by SEM, TEM, HRTEM, XRD, Raman, ESR and SQUID magnetization techniques. From the ESR and SQUID the metallic nature of the carbon spheres is described.