Reactable ionic liquid assisted solvothermal synthesis of graphite-like C3N4 hybridized alpha-Fe2O3 hollow microspheres with enhanced supercapacitive performance

A route to fabricate the graphite-like C3N4 hybridized alpha-Fe2O3 (g-C3N4/alpha-Fe2O3) hollow microspheres is designed. This route develops an ionic liquid system containing iron ions for manufacturing the g-C3N4/alpha-Fe2O3 hollow microspheres by a novel and eco-friendly solvothermal method at low temperature condition. The effect of ionic liquids on the morphology of the g-C3N4/alpha-Fe2O3 hybrid composites has been investigated in detail. It is found that ionic liquid 1-butyl-3-methylimidazolium tetrachlorideferrate(III) [Bmim]FeCl4 is supposed to have the triple roles of reactant, dispersing media and template at the same time, and is vital for the structure of the g-C3N4/alpha-Fe2O3 hollow microspheres. In addition, the capacitance of the g-C3N4/alpha-Fe2O3 hollow microspheres as electrode materials for supercapacitors is tested by cyclic voltammetry and chronopotentiometry measurements. The g-C3N4/alpha-Fe2O3 hollow microspheres exhibit large specific capacitance, excellent cycling performance and high Coulombic efficiency. The designed g-C3N4/alpha-Fe2O3 hollow microspheres show potential applications in supercapacitors. (C) 2013 Elsevier B.V. All rights reserved.