Facile Preparation and Enhanced Visible Light Photocatalytic Performance of AgI/Ag3PO4/WO3·H2O Heterojunction Photocatalysts

Using the prepared Ag 3 PO 4 /WO 3 ·H 2 O composite as the matrix, AgI nanoparticles were introduced onto the surface of Ag 3 PO 4 to construct AgI/Ag 3 PO 4 /WO 3 ·H 2 O ternary heterojunction photocatalysts. The ternary composite photocatalysts exhibited higher photocatalytic degradation activities for rhodamine B (RhB) and tetracycline hydrochloride (TCH) than those of binary Ag 3 PO 4 /WO 3 ·H 2 O and AgI/WO 3 ·H 2 O photocatalysts and individual AgI, Ag 3 PO 4 , and WO 3 ·H 2 O photocatalysts. After exposure to visible light for 12 and 24 min, the removal efficiencies of RhB and TCH by the S2-50% photocatalyst (50% molar percentage of AgI to Ag 3 PO 4 ) reached 98.0% and 85.3%, respectively. After four degradation cycles, the removal efficiency of RhB by S2-50% remained at 93.2%, significantly surpassing that of the Ag 3 PO 4 /WO 3 ·H 2 O photocatalyst. The enhanced photocatalytic performance of the AgI/Ag 3 PO 4 /WO 3 ·H 2 O photocatalyst is primarily attributed to the formation of Z-scheme/conventional Type II heterojunctions, which facilitate spatial separation of the photogenerated electrons and holes while maintaining the strong reductive capabilities of electrons in the AgI conduction band.