Porous carbon derived from Congo Red-adsorbed Chitosan for supercapacitor electrodes

Reuse of dye-containing wastewater for valuable products offers significant potential. Chitosan, a natural high-molecular-weight porous material, served as an effective carrier for dye molecules. This study uses chitosan to adsorb Congo Red, preparing hierarchical porous carbon materials, which are then applied in supercapacitors. The findings reveal that chitosan achieves an impressive adsorption capacity of 1450 mg g⁻¹ for Congo Red. When the chitosan–Congo Red composite material-based carbon is used as the electrode material, it shows an outstanding specific capacitance of 318 F g⁻¹ at a current density of 1 A g⁻¹. Furthermore, due to its high content of heteroatoms such as N, O, and S, the double-layer supercapacitor fabricated with this electrode material demonstrates a specific capacitance of 149.49 F g⁻¹ at 1 A g⁻¹, with an energy density of 8.77 Wh kg⁻¹ at a power density of 335.35 W kg⁻¹. These results highlight the considerable potential of this material after adsorption of dye-containing wastewater for applications in the energy storage field.