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

By controlling the pyrolysis temperature, core/shell materials with Fe3O4 encapsulated in carbon nanocages (Fe3O4@CNCs) and Fe encapsulated in carbon nanotubes (Fe@CNTs) were synthesized selectively from acetylene using Fe2O3 nanoparticles as catalyst in chemical vapor deposition. Scanning electron microscopic study showed that the efficiency of generating Fe3O4@CNCs and Fe@CNTs was high, exceeding 95%. Transmission electron microscopic study confirmed the high selectivity to Fe3O4@CNCs and Fe@CNTs, with the former having morphology similar to that of the catalyst particles. With Fe3O4 and Fe nanoparticles tightly wrapped in graphitic layers, the obtained Fe3O4@CNCs and Fe@CNTs materials show high stability and good magnetic properties. [Display omitted] •The paper reports a simple route for core/shell structure of carbon nanocomposites.•By controlling the temperature, Fe3O4@CNCs and Fe@CNTs can be synthesized selectively.•The obtained carbon nanocomposites show high magnetic properties.