In situ N, O co-doped porous carbon derived from antibiotic fermentation residues as electrode material for high-performance supercapacitors

Abstract

With the widespread use of antibiotics, the safe utilization of waste antibiotic fermentation residues has become an urgent issue to be resolved. In this study, in situ N, O co-doped porous carbon was prepared using fresh oxytetracycline fermentation residue under the mild activation of the green activator K₂CO₃. The optimal sample exhibited a 3D grid carbon skeleton structure, excellent specific surface area (S_BET = 948 m² g⁻¹), and high nitrogen and oxygen content (N = 3.42 wt%, O = 14.86 wt%). Benefiting from its developed morphology, this sample demonstrated excellent electrochemical performance with a high specific capacitance of 310 F g⁻¹ at a current density of 0.5 A g⁻¹ in the three-electrode system. Moreover, it exhibited superior cycling stability with only a 5.32% loss of capacity after 10 000 cycles in 6 M KOH aqueous electrolyte. Furthermore, the symmetric supercapacitor prepared from it exhibited a maximum energy density of 7.2 W h kg⁻¹ at a power density of 124.9 W kg⁻¹, demonstrating its promising application prospects. This study provided a green and facile process for the sustainable and harmless treatment of antibiotic fermentation residues.