In this work, a bulky Fe0/carbon matrix obtained by a low cost and simple reduction/carbonization of Fe3+ salt with sucrose was treated with CO2 to selectively oxidize the amorphous carbon to release the graphite like carbon coated magnetic Fe0 particles. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman, X-ray diffraction (XRD), BET, thermogravimetric analysis (TG) (in CO2) and particle size analyses showed that the treatment with CO2 of the Fe/carbon bulky composite led to the selective oxidation of the more amorphous carbon with the formation of 125-132 nm Fe@C nanoparticles with surface areas of 217 m2 g−1.