Hydrothermal-induced ɑ-Fe2O3/graphene nanocomposite with ultrahigh capacitance for stabilized and enhanced supercapacitor electrodes

Abstract

Pure and Fe2O3/graphene (G) nanocomposite was prepared by novel one-step hydrothermal method. XRD results suggest that rhombohedral phase of α-Fe2O3 (hematite, space group: R3c), which are consistent with the values given in the standard card (JCPDS no. 33-0664). The N2 adsorption–desorption results confirms that Fe2O3-G composite shows highest specific area (91 m2 g−1) and lower pore size of 10 nm compared with pristine Fe2O3 (surface area 76 = m2 g−1 and pore size = 17 nm). The electrochemical measurement demonstrates that Fe2O3/G composite shows a specific capacitance as high as 315 F g−1 at a discharge current density of 2 A g−1. Even at the current density of 10 A g−1, the specific capacitance is still as high as 185 F g−1. After 2000 cycles, the capacity retention is still maintained at 98%. This result suggests that the Fe2O3/G nanocomposite is a promising electrode material for high-energy density supercapacitor application.