Fabrication and supercapacitive properties of Fe2O3@C nanocomposites

Fe2O3@C nanocomposites (denoted as FeC-n, n represents the weight percent of Fe(NO3)(3)center dot 9H(2)O in the starting gel) have been fabricated by pyrolyzing Fe(NO3)(3)center dot 9H(2)O impregnated starch gels. When the Fe(NO3)(3)center dot 9H(2)O content was below 50 wt.%, the products contained well dispersive and uniform gamma-Fe2O3 nanoparticles that embedded in the carbon matrix. The particle sizes were positively related to the content of Fe(NO3)(3)center dot 9H(2)O. The nanocomposites FeC-50 that contained 4.25 nm nanoparticles exhibited an enhanced electrochemical performance within the voltage window of -1.3-0.4 V in 6 mol L-1 KOH solutions. The symmetric capacitor of FeC-50 possessed a high specific capacitance (SC) of 267.2 F g(-1) at 0.35 A g(-1) with a high voltage of 1.4 V. (C) 2012 Published by Elsevier B.V.