The graphitic carbon nitride (g-C3N4)/iron oxide (cx-Fe2O3) composites have been prepared by a one-step pyrolysis of Prussian blue (PB) and melamine. The Fe2O3 nanoparticles derived from PB effectively protect the thin layers of g-C3N4 from restacking and expanding. The as-prepared g-C3N4/alpha-Fe2O3 composites exhibit a large specific surface area, and demonstrate their excellent electrochemical performance in the supercapacitor and non-enzymatic detection of glucose. The g-C3N4R/alpha-Fe2O3 composites facilitate the faster faradic reaction in 1.0 M KOH electrolyte, and deliver the highest specific capacitance (580 Fg(-1)) at the current density of 1.0 A g(-1). The resultant composites also show an excellent long cycle life (up to 1000 cycles) at the current density of 2 Ag-1. In addition, the modified electrode based on the g-C3N4/ce-Fe2O3 hybrids are also used for the non-enzymatic detection of glucose. The as-fabricated modified electrode exhibits good electrochemical performance towards the oxidation of glucose with a response time <3 s and a linear range of 2.0 x 10(-6) - 2.4 x 10(-3) MOl L-1. The electrode modified by the g-C3N4/alpha-Fe2O3 composites exhibits good anti-interference performance and stability. The g-C3N4/alpha-Fe2O3 hybrids have great potential in the application of electrochemical storage devices and sensors. (C) 2016 Elsevier B.V. All rights reserved.