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

Abstract

• Bi 2 O 2 CO 3 /g-C 3 N 4 /Bi 2 O 3 dual Z-scheme heterostructure was easily prepared by precipitation-calcination method. • The matching band gap of heterostructure greatly promotes the transfer of the carrier, which makes full use of the reducibility of the conduction band and the oxidation of the valence band. • The possible pathways of TC degradation intermediates were reasonably deduced by LC-MS. • The toxicity analysis were evaluated based on quantitative structure activity relationship QSAR and structure of warning. In this study, a floral and lamellar interlaced double Z-scheme ternary heterojunction Bi 2 O 2 CO 3 /g-C 3 N 4 /Bi 2 O 3 was prepared by a simple precipitation and acalcination methods. TEM images demonstrated the flower-like layered structures of 3D Bi 2 O 2 CO 3 and Bi 2 O 3 were interwoven with the 2D g-C 3 N 4 block structures. The synthesized heterostructure indicated the enhanced photocatalytic performance in tetracycline (TC) degradation compared with single Bi 2 O 2 CO 3 , Bi 2 O 3 and g-C 3 N 4 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 Bi 2 O 2 CO 3 /g-C 3 N 4 /Bi 2 O 3 . 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.