Effect of Transition Metal Addition on the Transformation of Carbon Black to Hollow Onion-like Nanostructural Carbon

Hollow onion-like nanostructural carbon was constructed from acetylene carbon black with the aid of Fe,Co and Ni catalysts through the catalytic carbonization.The morphologies and structures of pristine carbon black and its carbonized products were investigated by using TEM,HRTEM,XRD and Raman spectroscopy measurements.The hollow onion-like nanostructural carbon mainly consists of quasi-spherically concentric graphite shells enclosing voids with interlayer spacing of 0.34nm.It is originated from the carbon-encapsulated metal nanoparticles by the dissolution-precipitation process between carbon and transition metal catalysts.The product catalyzed by Fe exhibits the typical and regular shape of onion-like nanostructural carbon and higher degree of graphitization.These imply that Fe possesses the better catalytic effect among these three metals.