Characterization of graphitic nanofibers synthesized by the CVD method using nickel-copper as a catalyst

We have investigated the relationship between microstructure changes of Ni-Cu catalyst and the morphological changes of graphitic nanofibers with synthesis condition of graphitic nanofibers. In this work, Ni-Cu catalyst was prepared by the co-precipitation method using aqueous solution of nickel and copper nitrates. Production of graphitic nanofibers was performed by pyrolysis of acetylene on Ni-Cu/alumina catalyst at 600-700 °C. The catalyst and the graphitic nanofibers were characterized by FE-SEM, FE-TEM and EDXS. We observed shape, microstructure and composition of the catalyst which was catalyst of manufacture step, process and metal catalyst after synthesis. A change of catalyst through each step is studied in relation to the synthesized graphitic nanofiber. Morphologies of graphitic nanofibers synthesized at 600 and 700 °C appeared a spiral and straight type, respectively. Together it exists the possibility of knowing there were two forms from interim step. Observation of FE-TEM and FE-SEM revealed that change of catalyst shape appeared by catalyst aggregation in high reduction temperature before graphitic nanofibers, synthesis, which caused morphologies variation of graphitic nanofibers. Also it was confirmed that morphology of GNFs was controlled by rather reduction temperature before synthesis than synthesis temperature.