Applied Surface Science, Vol.456, 473-481, 2018
A novel Z-scheme Bi2MoO6/BiOBr photocatalyst for enhanced photocatalytic activity under visible light irradiation
In this work, BiOBr was firstly prepared by using a facile solvothermal approach at 393 K for 24 h, and then Bi2MoO6 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 Bi2MoO6/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 Bi2MoO6/BiOBr heterojunctions exhibited substantially improved performance for removal of methylene blue (MB), compared with BiOBr and Bi2MoO6 samples under 410nm light excitation. The constant K-app of 20% Bi2MoO6/BiOBr is 0.0539 min(-1), which is 4.4 and 6.9 times higher than that of Bi2MoO6 (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.