LAUSR

Abstract Carbon nano-onions (CNOs) have recently attracted an important attention thanks to their exceptional physical/chemical characteristics which allow the encapsulation of specific materials of interest and their application in key electrochemical processes. In this work we have investigated the structural properties, magnetic characteristics and electrochemical performances of recently discovered radial hybrid-systems comprising CNOs and carbon nanotubes (CNTs) filled with long Fe3C crystals. We report the presence of important pseudo-capacitor performances related to the formation of sulfur-induced defects in the CNTs structures as well as to the presence of iron oxides. In addition unusual not previously observed (in this type of materials) anodic and cathodic peaks in the measured voltammograms were found. We attribute such peak-features to diffusion effects in the highly defective mixed Russian-doll/jelly-roll structure of the CNTs. Also, not previously reported dislocation effects in one dimensional atomic chains of Fe3C were found.