Ultrasonic-assisted preparation of plasmonic ZnO/Ag/AgWO nanocomposites with high visible-light photocatalytic performance for degradation of organic pollutants.

In this work, plasmonic ternary ZnO/Ag/AgWO nanocomposites as efficient visible-light-driven photocatalysts prepared by a facile ultrasonic-irradiation method. The as-prepared samples were characterized by XRD, SEM, TEM, EDX, XPS, UV-vis DRS, FT-IR, and PL techniques. The photocatalytic performance of the prepared ZnO/Ag/AgWO nanocomposites were evaluated by photodegradations of rhodamine B, methylene blue, methyl orange, and fuchsine under visible-light irradiation. The optimal nanocomposite with 15wt% of Ag/AgWO to ZnO showed the highest photocatalytic activity for RhB degradation, which is about 95 and 19 times higher than those of the Ag/AgWO and ZnO samples, respectively. The highly enhanced activity of the ZnO/Ag/AgWO (15%) nanocomposite was attributed to the surface plasmon resonance effect of metallic silver and the formation of heterojunctions between the counterparts, which effectively suppresses recombination of the photogenerated charge carriers. Lastly, the plasmon-enhanced photocatalytic mechanism associated with the ZnO/Ag/AgWO nanocomposites was discussed.