Facile Fabrication of Bi 2WO 6/Ag 2S Heterostructure with Enhanced Visible-Light-Driven Photocatalytic Performances

In this report, a novel photocatalyst based on Bi 2 WO 6 /Ag 2 S heterostructures was prepared by a 3-mercaptopropionic acid (MPA)-assisted route at room temperature. Compared to bare Bi 2 WO 6 and Ag 2 S nanoparticles, the as-formed Bi 2 WO 6 /Ag 2 S heterostructures exhibit enhanced photocatalytic activity for the degradation of rhodamine B (Rh B) under visible-light irradiation. This kind of enhancement in the photocatalytic activity is considered to be the synergistic effects of both the effective electron-hole separation and expansion of the light-absorption range. The pH of the solution is of vital importance to the photocatalytic activity of the as-formed Bi 2 WO 6 /Ag 2 S heterostructures. Under low pH value, the photosensitization process is suppressed, while under higher pH value, the photosensitization process is favored. The mechanism of the photocatalytic process was proposed by the active-species-trapping experiments, indicating that the photogenerated holes (h + ) play a crucial role in the degradation of Rh B under visible light. The enhanced photocatalytic performance of this heterostructure makes it a promising material for the treatment of dye-containing wastewater.