Discarded antibiotic mycelial residues derived nitrogen-doped porous carbon for electrochemical energy storage and simultaneous reduction of antibiotic resistance genes(ARGs)

The question of how to reasonably dispose and recycle antibiotic mycelial residues (AMRs), a hazardous waste, is a critical issue. The AMRs containing nitrogen-rich organic matters shows a promising alternative feedstock of nitrogen-doped porous carbons (NPCs). Here, the NPCs with the ultrahigh surface area (2574.9 m2 g−1) were prepared by using the discarded oxytetracycline mycelial residues (OMRs) and further used as an electrode for supercapacitor. A series of experiments including scanning/transmission electron microscope, Brunauer-Emmett-Teller measurement, and electrochemical impedance spectrum revealed that the NPC-2-900 exhibited a high N content, large surface area, and high electrical conductivity. The electrochemical performance of the NPC was tested by cyclic voltammetry, galvanostatic charge/discharge cycling, and rate capability test. The optimized NPC-2-900 displayed distinguish specific capacitance (307 F g−1), cycling stability (over 95% capacitance retention after 2000 cycles even at a high current density of 20 A g−1) and superior rate performance. Of particular interest, the qPCR test indicates the ARGs were reduced in the conversion process from OMRs to NPCs.