Synthesis and characterization of rGO/Fe₂O₃ nanocomposite as an efficient supercapacitor electrode material

The reduced graphene oxide-Fe₂O₃ (rGO-Fe₂O₃) nanocomposites were synthesized by a facile and low-cost hydrothermal method employing rGO and Iron (III) nitrate precursors. The synthesis parameters including the reduction time and presence of reduction aid are studied. The structural and morphological studies of the nanocomposites were investigated by using Raman spectra, Fourier transform infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscopy. The results indicate that Fe₂O₃ nanoparticles with average particle size of 25 nm are well anchored on graphene sheets and the weight percent of the nanoparticles in the nanocomposites was influenced by the reduction time. The as-synthesized nanocomposites were characterized by a three-electrode system using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge–discharge in 1 M KOH aqueous solution. The electrodes made of rGO-Fe₂O₃ nanocomposite synthesized by urea as reduction aid showed a high specific capacitance of 291 F g⁻¹ at 1 A g⁻¹ in the potential range of − 1 to 0 V. The best electrochemical performance of urea reducted rGO-Fe₂O₃ nanocomposites is basically attributed to the effect of Fe₂O₃ nanoparticles in preventing the restacking of rGO sheets.