Large-scale synthesis of hollow highly-graphitic carbon nanospheres by the reaction of AlCl3·6H2O with CaC2

Hollow carbon nanospheres (HCNSs) were prepared on large scale by the reaction of AlCl3·6H2O and CaC2 in the temperature range of 250–500 °C. Characterization of the products by X-ray diffraction, Raman spectroscopy and transmission electron microscopy indicates that they have a uniform size of about 30 nm and a high degree of graphitization. Based on a series of comparative experiments and the systematic characterization of the products, both the water of crystallization and AlCl3 in AlCl3·6H2O play crucial roles in preparing the HCNSs. It was found that AlCl3 exhibits a strong graphitization behavior on solid carbon nanospheres even at low temperatures, and the graphitization contributes to their evolution to HCNSs.