In-situ synthesis of graphene encapsulated Fe/Fe2O3 nanoparticles for possible biomedical applications

This paper reports on the in-situ synthesis, optimization, characterization and cytotoxicity tests of multi-layer graphene (MLG) encapsulated Fe/Fe2O3 nanoparticles (Fe/Fe2O3@C core–shell nanostructures) by spray drying-assisted chemical vapor deposition (CVD) using iron-nitrate/silica-based precursors. The influences CVD reaction temperature, holding time, CH4/H2 gas flows pressure synthesis MLG were investigated. CVD-synthesized powders purified acid leaching to remove residual silica probable uncoated Fe/Fe-oxide phases. XRD analyses revealed presence FCC (Fe,C), BCC Fe, graphite/graphene trace amount Fe2O3 Raman spectra confirmed existence shells. TEM indicated that (from at least 3 maximum 35 layers) wrapped around metallic cores ranged between 4 85 nm. Purification did not degrade, dissolve or create discontinuity structure. VSM measurements showed obtained from optimized conditions (900 °C, 100 ml/min CH4/H2, 50 mbar) had a soft ferromagnetic behavior with low saturation magnetization (∼85 emu/g) coercivity (∼552 Oe) values. Optimized successfully suspended in water poly(acrylic acid) coating. Aqueous cytocompatible below μg/ml short incubation times, potential be used biomedical applications.