1. Visible-light induced tetracycline degradation catalyzed by dual Z-scheme InVO4/CuBi2O4/BiVO4 composites: The roles of oxygen vacancies and interfacial chemical bonds.
- Author
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Liu, Jue, Li, Shiwen, Meng, Can, Sun, Jing, Li, Xian, Hu, Yuanan, and Cheng, Hefa
- Subjects
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CHEMICAL bonds , *INTERFACIAL bonding , *TETRACYCLINE , *TETRACYCLINES , *HETEROJUNCTIONS , *REACTIVE oxygen species - Abstract
[Display omitted] • Z-scheme InVO 4 /CuBi 2 O 4 /BiVO 4 composites were fabricated with hydrothermal synthesis. • Interfacial Bi O bonds boosted the charge transfer from InVO 4 and BiVO 4 to CuBi 2 O 4. • O vacancies brought by orthovanadates enhanced 1O 2 production through energy transfer. • InVO 4 /CuBi 2 O 4 /BiVO 4 showed good photocatalytic activity for tetracycline degradation. • The composite had good reusability, stability, and performed well in natural water. Dual Z-scheme InVO 4 /CuBi 2 O 4 /BiVO 4 (CuInBi) composites with rich oxygen vacancies and chemical bonds at the heterojunction interfaces were fabricated, for the first time, through hydrothermal method with post annealing treatment, in which CuBi 2 O 4 acts as a bridge to connect InVO 4 and BiVO 4. The as-prepared composites exhibited superior photocatalytic activity compared with the individual semiconductors. Specifically, the degradation rate of tetracycline (20 mg/L) in the presence of CuInBi-1 (1.0 g/L) was up to 5.4, 2.8, and 3.1 times faster than those in the presence of CuBi 2 O 4 , InVO 4 , and BiVO 4 , respectively. The enhanced photocatalytic performance could be partially attributed to the good light absorption of CuBi 2 O 4 , which broadens the visible light response of the InVO 4 /CuBi 2 O 4 /BiVO 4 composites. Meanwhile, the interfacial chemical bonds in the dual Z-scheme heterojunction help accelerate charge separation and maintain strong redox activity. In addition, the oxygen vacancies, induced mainly by the low-valent vanadium atoms, facilitate the production of singlet oxygen (1O 2) through energy transfer, which easily attacks the electron-rich groups, including phenolic group, dimethylamino group, amine group, and double bonds, in tetracycline. The InVO 4 /CuBi 2 O 4 /BiVO 4 composite exhibited excellent reusability and stability, and performed well in photocatalytic degradation of tetracycline in river water and under natural sunlight, demonstrating great potential for practical application. The probable photocatalytic mechanism of InVO 4 /CuBi 2 O 4 /BiVO 4 composite was proposed according to the results of density functional theory (DFT) calculations, and the reactive oxygen species (ROSs) and major degradation intermediates detected in the photocatalytic system. This work demonstrates the important roles of oxygen vacancies and interfacial chemical bonds in boosting the photocatalytic activity of Z-scheme heterojunctions and provides a reference for the construction of high-activity photocatalysts for efficient degradation of antibiotics. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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