Preparation and characterization of pitch-based carbon nanospheres

Aqua-mesophase pitch (AMP) was prepared from the oxidation of medium coal tar pitch with a mixture of concentrated sulfuric acid and nitric acid, and then pitch-based carbon nanospheres were prepared by using carbon sol-gel method in water-in-oil emulsion formed by silicone and AMP. AMP, carbon primary powders and carbon nanospheres were characterized by FT-IR, TG, TEM and X-ray diffraction analysis. The results show that nitration, oxidation and sulfonation reaction happen during the preparation of AMP. Nitro, hydroxyl, carboxyl and sulfonic functional groups are removed during the carbonizing process of carbon nanospheres preparation. Water removal, functional groups decomposition and carbon skeleton rearrangement are main three stages during carbon primary powders pyrolysis. The diameter of most carbon nanospheres which presented disorganized layer graphite structure is about 50 nm. Moreover the sphericity and d₀₀₂of nanospheres are 95.9% and 0.348 0 nm, respectively.