Ultrahigh specific capacitance of α-Fe2O3 nanorods-incorporated defect-free graphene nanolayers

The development of hybrid materials with high pseudocapacitance and electrical double layer capacitance is an urge for the fabrication of efficient supercapacitor electrodes. Herein, a highly effective, easily performable, high-yielding, and economical method is demonstrated for the preparation of α -Fe2O3 nanorods incorporated defect-free graphene nanosheets that showed excellent supercapacitor performance. α -Fe2O3/graphene nanocomposite has been synthesized by an interlayer catalytic exfoliation of α -Fe2O3 intercalated graphite which showed high conductivity of 3.1 × 106 S/cm. α -Fe2O3/graphene nanocomposite modified carbon paste electrode exhibited ultrahigh specific capacitance values of 1135 mF/cm2 at a scan rate of 5 mV/s and 815 mF/cm2 at a current density of 0.5 mA/cm2. The fast ionic diffusion with no charge transfer resistance of the electrode material was revealed from the electrochemical impedance spectroscopic analysis. α -Fe2O3/graphene nanocomposite showed 100 folds of increase in the specific capacitance compared to α -Fe2O3 and graphene, suggesting their synergistic effect in the nanocomposite leading to a drastic increase in the specific capacitance. The composite displayed good cyclic stability of 79.9% retention of the initial capacitance after 1500 cycles and 54.9% after 10,000 repeated cycles.