Ag3PO4/ZnO: An efficient visible-light-sensitized composite with its application in photocatalytic degradation of Rhodamine B

The efficient visible-light-sensitized Ag3PO4/ZnO composites with various weight percents of Ag3PO4 were prepared by a facile ball milling method. The photocatalysts were characterized by XRD, DRS, SEM, EDS, XPS, and BET specific area. The OH radicals produced during the photocatalytic reaction was detected by the TA–PL technique. The photocatalytic property of Ag3PO4/ZnO was evaluated by photocatalytic degradation of Rhodamine B under visible light irradiation. Significantly, the results revealed that the photocatalytic activity of the composites was much higher than that of pure Ag3PO4 and ZnO. The rate constant of RhB degradation over Ag3PO4(3.0 wt.%)/ZnO is 3 times that of single-phase Ag3PO4. The optimal percentage of Ag3PO4 in the composite is 3.0 wt.%. It is proposed that the OH radicals produced in the valence band of ZnO play the leading role in the photocatalytic degradation of Rhodamine B by Ag3PO4/ZnO systems under visible light irradiation.

The free OH radicals generated in the VB of ZnO play the primary role in the visible-light photocatalytic degradation of RhB in Ag3PO4/ZnO system. The accumulated electrons in the CB of Ag3PO4 can be transferred to O2 adsorbed on the surface of the composite semiconductors and H2O2 yields. H2O2 reacts with electrons in succession to produce active OH to some extent.Figure optionsDownload as PowerPoint slideHighlights
► Efficient visible-light-sensitized Ag3PO4/ZnO composites were successfully prepared.
► Effect of Ag3PO4 content on the catalytic activity of Ag3PO4/ZnO is studied in detail.
► Rate constant of RhB degradation over Ag3PO4(3.0 wt.%)/ZnO is 3 times that of Ag3PO4.
► The active species in RhB degradation are examined by adding a series of scavengers.
► Visible light degradation mechanism of RhB over Ag3PO4/ZnO is systematically studied.