Fe₂O₃/hemp straw-based porous carbon composite for supercapacitor electrode materials

The porous activated carbon material was prepared using hemp straw as the biomass carbon source, which was used as the substrate material to synthesize Fe₂O₃/porous carbon nanocomposites (Fe₂O₃/HAC) by simple and effective hydrothermal method. The results show that the porous activated carbon based on hemp straw is an ideal substrate for Fe₂O₃, which can effectively avoid the agglomeration of metal oxides, increase the contact area with electrolyte, and shorten the ion diffusion path, so as to improve the electrochemical performance of the material. In three-electrode system, the electrochemical performance of Fe₂O₃/HAC is much higher than that of HAC and Fe₂O₃ alone. At the current density of 1 A g⁻¹, its specific capacitance is 256 F g⁻¹, and it has the best capacity retention. The symmetrical device composed of the material has a good capacitance value and excellent cycle stability.