Fabrication, characterization and photocatalytic mechanism of a novel Z-scheme BiOBr/Ag3PO4@rGO composite for enhanced visible light photocatalytic degradation

The Z-scheme BiOBr/Ag3PO4@rGO photocatalyst was successfully fabricated by solvothermal and precipitation methods, and the as-obtained nanocomposite photocatalytic efficiency was assessed by the degradation of tetracycline (TC). The physicochemical properties of the nanocomposite were confirmed by XRD, SEM, TEM, BET, XPS, DRS, PL, PC, and EIS measurements. The prepared BiOBr/Ag3PO4@rGO composite exhibited fast degradation efficiency for TC, with an elimination rate of 98.5% in 24 min. The species capture experiment and the ESR study showed that center dot O-2(-), center dot OH and h(+) all took part in the TC degradation. Furthermore, the photocatalytic mechanism of BiOBr/Ag3PO4@rGO nanocomposites can be described by the Z-scheme charge transfer mechanism. The synergistic effect of rGO and BiOBr/Ag3PO4 also contributed to improve the photostability and recyclability of the TC decomposition. The study provides a new awareness of the degradation of organic pollutants, thereby indicating that it has high potential for practical wastewater treatment. (C) 2019 Elsevier B.V. All rights reserved.