A novel Z-scheme Bi2MoO6/BiOBr photocatalyst for enhanced photocatalytic activity under visible light irradiation

Abstract In this work, BiOBr was firstly prepared by using a facile solvothermal approach at 393 K for 24 h, and then Bi 2 MoO 6 well dispersed on the surface of BiOBr at 433 K for 3 h. The shape, chemical composition, crystal structure, optical property and surface area of Bi 2 MoO 6 /BiOBr were investigated by field emission electron microscope (FESEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N 2 adsorption-desorption isotherms and UV–Vis diffuse reflectance spectroscopy (DRS). The Bi 2 MoO 6 /BiOBr heterojunctions exhibited substantially improved performance for removal of methylene blue (MB), compared with BiOBr and Bi 2 MoO 6 samples under 410 nm light excitation. The constant K app of 20%Bi 2 MoO 6 /BiOBr is 0.0539 min −1 , which is 4.4 and 6.9 times higher than that of Bi 2 MoO 6 (0.0121 min −1 ) and BiOBr (0.0078 min −1 ). The prominent enhancement of activity is due to the high charge separation capacity, which resulted from the matched band alignment of two components. Finally, the Z-scheme photocatalytic mechanism was confirmed by radical trapping experiment.