N- and O self-doped biomass porous carbon cathode in an electro-Fenton system for Chloramphenicol degradation

Cathode catalysts of Electro-Fenton (EF) system with high activity, selectivity and stability are necessary for efficient electrochemical H₂O₂ generation. To this end, the N- and O self-doped biomass porous carbon (NOBPC) are synthesized by black soya bean, which was as cathode materials in the EF system for the degradation of Chloramphenicol. The NOBPC cathode material exhibits large surface area (663.6 m² /g), plentiful porous structure and doping contents of nitrogen and oxygen, which facilitates dissolved O₂ diffusion and enhances the electro-Fenton activity and stability. The maximum H₂O₂ production rate could reach 6.32 mmol/L/h at pH 1, −0.7 V vs SCE. Moreover, the removal efficiency of Chloramphenicol achieves 100% in 80 min at the optimum condition (-0.5 V, pH 3 and Fe²⁺ 1.0 mmol/L). More importantly, the possible degradation mechanism is investigated by LC-MS. The C-Cl bond of Chloramphenicol was easily oxidized by •OH, and then the cleavage of the benzene ring appeared and further transformed into small molecules. Copyright © 2020 Elsevier B.V. All rights reserved.