A facile route to synthesize core/shell structured carbon/magnetic nanoparticles hybrid and their magnetic properties

Graphical abstract: Controllable synthesis of core/shell structured carbon/magnetic nanoparticles hybrid and their tunable magnetic properties. - Highlights: • The paper reports a simple route for core/shell structured carbon/magnetic nanoparticles hybrid. • By controlling the temperature, Fe₃O₄@CNCs, Fe@HCNTs and Fe@LCNTs were produced selectively. • The magnetic properties of the obtained core/shell structured hybrid could be tuned effectively. - Abstract: By controlling the pyrolysis temperature, core/shell structured Fe₃O₄/carbon nanocages, Fe/helical carbon nanotubes and Fe/low helicity of carbon nanotubes could be synthesized selectively over Fe₂O₃ nanotubes generated by a hydrothermal method. The transmission electron microscopic and scanning electron microscopic investigations revealed that the efficiency of generating core/shell structured hybrid was high, exceeding 90%. Because of the magnetic nanoparticles tightly wrapped in graphitic layers, the obtained core/shell structured hybrids showed high stability and good magnetic properties. And the magnetic properties of the obtained core/shell structured hybrid could be tuned by the decomposition temperature and time. Therefore, a simple, inexpensive and environment-benign route was proposed to produce magnetism-tunable core/shell structured hybrid in large quantities