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

摘要

Pure and Fe2O3/graphene (G) nanocomposite was prepared by novel one-step hydrothermal method. XRD results suggest that rhombohedral phase of -Fe2O3 (hematite, space group: R3c), which are consistent with the values given in the standard card (JCPDS no. 33-0664). The N-2 adsorption-desorption results confirms that Fe2O3-G composite shows highest specific area (91m(2)g(-1)) and lower pore size of 10nm compared with pristine Fe2O3 (surface area 76=m(2)g(-1) and pore size=17nm). The electrochemical measurement demonstrates that Fe2O3/G composite shows a specific capacitance as high as 315Fg(-1) at a discharge current density of 2Ag(-1). Even at the current density of 10Ag(-1), the specific capacitance is still as high as 185Fg(-1). After 2000cycles, 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.