On the morphological, structural and electrochemical properties of entangled Cu-filled carbon nano-onions.

In this work we demonstrate an advanced chemical vapour synthesis approach in which the synthesis of Cu-filled carbon nano-onions (CNOs) is achieved by direct sublimation and pyrolysis of a not previously used precursor, namely chloro(1,5-cyclooctadiene)copper(i) dimer. The cross-sectional morphology and filling-ratio of the as grown CNOs were characterized by detailed transmission electron microscopy (TEM), high resolution TEM analyses, Fourier transform and lattice profile analyses. The structural graphitic arrangement and electronic properties of the CNOs were then investigated by means of X-ray diffraction and absorption spectroscopy. The electrochemical impedance spectroscopy and cyclic voltammetry of presented structures were also investigated and reveal a high electrical resistance. Finally the electrochemical performances of this type of CNOs were compared with those of another type of CNOs filled with different metal-carbide materials.