Insight into the Mechanisms of Chloramphenicol Degradation by Photocatalysis Coupled Microbial Fuel Cell with Ni/Mxene Photocathode

Chloramphenicol (CAP), as a broad-spectrum antibiotic, has become an environmental problem for its harmfulness and toxicity. A novel strategy was achieved by photocatalysis coupled with microbial fuel cell (Photo-MFC) over Ni/MXene photocathode for enhancing the degradation efficiency of (CAP). It was demonstrated that the best degradation efficiency of CAP can reach 82.62% after 36 h under the optimal conditions (pH = 2). Based on density functional theory (DFT) calculations and high-performance liquid chromatography-mass (HPLC-MS) spectrometry, it is speculated that the degradation mechanism of CAP in Photo-MFC over Ni/MXene photoelectrode is achieved by destroying the two asymmetric centers and nitro, including the hydrodechlorination, nitro reduction reaction, hydroxylation reaction, cleavage of C-N bond and ring-opening reaction of benzene ring. Finally, the ecotoxicity evaluation of the degradation products showed that the CAP degradation in the Ni/MXene modified photo-MFC system showed a remarkable tendency to the low-toxicity level.