Construction of layered embedding dual Z-Scheme Bi2O2CO3/g-C3N4/Bi2O3: Tetracycline degradation pathway, toxicity analysis and mechanism insight

In this study, a floral and lamellar interlaced double Z-scheme ternary heterojunction Bi2O2CO3/g-C3N4/Bi2O3 was prepared by a simple precipitation and acalcination methods. TEM images demonstrated the flower-like layered structures of 3D Bi2O2CO3 and Bi2O3 were interwoven with the 2D g-C3N4 block structures. The synthesized heterostructure indicated the enhanced photocatalytic performance in tetracycline (TC) degradation compared with single Bi2O2CO3, Bi2O3 and g-C3N4 under simulated solar irradiation. Besides, organic pollutants including ciprofloxacin (CIP), methylene blue (MB), and rhodamine B (Rh B) were further used to evaluate the photocatalytic activity of Bi2O2CO3/g-C3N4/Bi2O3. The effects of pH, supporting electrolyte on photocatalytic performance were also investigated. Furthermore, the possible pathways of TC degradation intermediates were reasonably deduced by liquid mass spectrometry (LC-MS), and the toxicity analysis were evaluated based on quantitative structure activity relationship (QSAR) and structure of warning. Finally, according to free radical trapping experiments a double Z-scheme photocatalysis mechanism was proposed.