Facile synthesis of O/N co-doped hierarchical porous carbon: for high performance supercapacitors and electromagnetic interference shielding

Abstract

Biomass-derived carbon materials are being increasingly utilized in various fields. This paper reports a facile synthesis method for O/N co-doped hierarchical porous carbon, utilizing the inherent pore structure and high heteroatom content of sesame meal. The O/N co-doped hierarchical porous carbon (SC-120) exhibits a hierarchical pore structure and abundant surface functional groups, the specific surface area reached 1743 m² g⁻¹, and the O and N element contents were measured at 10.87% and 1.95% respectively. In the three-electrode system, the specific capacitance of SC-120 reached 358.6 F g⁻¹ at a current density of 0.5 A g⁻¹, and a specific capacitance of 262.5 F g⁻¹ is maintained even at a high current density of 30 A g⁻¹. Constructed using SC-120 as the electrode, the symmetrical supercapacitor exhibits a high energy density of 9.23 W h kg⁻¹ at a power density of 100 W kg⁻¹ and excellent cyclic stability of 93.58% capacitance retention rate after 7500 charge–discharge testing. Additionally, SC-120 demonstrates potential for electromagnetic interference shielding, attaining an efficiency of 33.18 dB and a shielding effectiveness of 99.59% within the X-band frequency range of 8.2–12.4 GHz.