Bismuth vanadate-loaded graphitized carbon nitride nanosheet composites for significantly enhanced activation of persulfate to remove cefixime and degradation mechanism

Advanced oxidation process (AOPs) is currently the main technique for the removal and treatment of antibiotics in environmental water. Based on the thought of structural design, bismuth vanadate (BiVO4)-loaded graphitized carbon nitride nanosheet (g-C3N4-NS) composites have been synthesized using a simple in-situ embedding method. The insertion of BiVO4 crystals between the lamellar g-C3N4 would significantly increase the specific surface area (51.03 m2 g- 1) of the composites as a way expose more active sites and enhance the utilization. Besides, narrower band gap, wider light absorption range, and superior charge separation ability, which could enhance the overall photocatalytic degradation performance of the materials. The removal efficiency of cefixime by the g-C3N4-NS/BiVO4(8:2)/PS (CNB-8/PS) system could reach 96 % after 30 min under simulated sunlight irradiation. In addition, after five cycles of degradation experiments, the removal rate only decreased by 9.5 %, indicating that the materials had good stability, reusability, and environmental utilization value. The catalytic mechanism of the degradation system analyzed, that center dot O2- had the greatest effect on the removal of cefixime. This work provides data support for further development of structurally modified g-C3N4-based photocatalysts to degrade antibiotics in water.