Controllable synthesis, characterization, and magnetic properties of magnetic nanoparticles encapsulated in carbon nanocages and carbon nanotubes

摘要

By controlling the pyrolysis temperature, core/shell materials with Fe_3O_4 encapsulated in carbon nanocages (Fe_3O_4@CNCs) and Fe encapsulated in carbon nanotubes (Fe@CNTs) were synthesized selectively from acetylene using Fe_2O_3 nanoparticles as catalyst in chemical vapor deposition. Scanning electron microscopic study showed that the efficiency of generating Fe_3O_4@CNCs and Fe@CNTs was high, exceeding 95%. Transmission electron microscopic study confirmed the high selectivity to Fe_3O_4@CNCs and Fe@CNTs, with the former having morphology similar to that of the catalyst particles. With Fe_3O_4 and Fe nanoparticles tightly wrapped in graphitic layers, the obtained Fe_3O_4@CNCs and Fe@CNTs materials show high stability and good magnetic properties.