Functional partition of Fe and Ti co-doped g-C3N4 for photo-Fenton degradation of oxytetracycline: Performance, mechanism, and DFT study

In this study, we synthesized Fe and Ti co-doped graphitic carbon nitride (FTCN) with high catalytic ability by a two-step calcination method. The photoelectrochemical results indicated that FTCN possessed a reduced bandgap and promoted photocarrier transfer efficiency, which enables FTCN excellent performance on oxytetracycline (OTC) degradation (90 % within 10 min). The main reactive oxygen species and the intermediates of OTC in the photo-Fenton process were obtained. Experimental data and density functional theory (DFT) were combined to explore the mechanism in depth. Interestingly, it was found that Fe and Ti respectively act as the main activation centers of H2O2 and O2, while few oxygen-containing metal active sites participate in the activation process. The synergistic effect of bimetallic doping plays a significant role in enhancing the photoFenton catalytic performance. Hopefully, a new approach to design highly efficient multifunctional catalysts or dual single-atom catalysts can be developed.