Molecular engineering of donor-acceptor structured g-C3N4 for superior photocatalytic oxytetracycline degradation

The inherent structural defects of graphitic carbon nitride (g-C3N4), especially low separation efficiency of photogenerated carriers, have greatly limits its photocatalytic degradation ability towards pollutants. Conjugated g-C3N4 (CN) with tailored donor-acceptor units have recently attracted great attention because of the controlled optical bandgap and favorable separation of charge carriers. Here, a novel 5-bromo-2-thiophenecarboxaldehyde (BTC) grafted CN photocatalyst (TCN) was prepared. The results have showed that this new material has significant performance advantages. Up to 2.43-fold apparent rate constant improvement in photocatalytic OTC degradation was realized using TCN-5 compared to CN, and the efficiency for OTC degradation was as high as 93%. And at the end of the reaction (at 60 min), the removal efficiency of TOC was 38%, which should be due to the accelerated the intramolecular charge separation and controllable electron migration. This work unravels intramolecular charge transfer in donor-acceptor structured CN for oxytetracycline photocatalytic degradation, which is expected to bring a promising approach for the photocatalytic degradation of antibiotics.

Automated summary

In this study, a novel CN photocatalyst with improved photocatalytic degradation efficiency was prepared for the degradation of oxytetracycline, providing a promising approach for the photocatalytic degradation of antibiotics.