Fe₂O₃ Embedded in N-Doped Porous Carbon Derived from Hemin Loaded on Active Carbon for Supercapacitors

The high power density and long cyclic stability of N-doped carbon make it an attractive material for supercapacitor electrodes. Nevertheless, its low energy density limits its practical application. To solve the above issues, Fe₂O₃ embedded in N-doped porous carbon (Fe₂O₃/N-PC) was designed by pyrolyzing Hemin/activated carbon (Hemin/AC) composites. A porous structure allows rapid diffusion of electrons and ions during charge-discharge due to its large surface area and conductive channels. The redox reactions of Fe₂O₃ particles and N heteroatoms contribute to pseudocapacitance, which greatly enhances the supercapacitive performance. Fe₂O₃/N-PC showed a superior capacitance of 290.3 F g^-1 at 1 A g^-1 with 93.1% capacity retention after 10,000 charge-discharge cycles. Eventually, a high energy density of 37.6 Wh kg^-1 at a power density of 1.6 kW kg^-1 could be delivered with a solid symmetric device.