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

Abstract

Using the prepared Ag₃PO₄/WO₃·H₂O composite as the matrix, AgI nanoparticles were introduced onto the surface of Ag₃PO₄ to construct AgI/Ag₃PO₄/WO₃·H₂O ternary heterojunction photocatalysts. The ternary composite photocatalysts exhibited higher photocatalytic degradation activities for rhodamine B (RhB) and tetracycline hydrochloride (TCH) than those of binary Ag₃PO₄/WO₃·H₂O and AgI/WO₃·H₂O photocatalysts and individual AgI, Ag₃PO₄, and WO₃·H₂O 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 Ag₃PO₄) 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 Ag₃PO₄/WO₃·H₂O photocatalyst. The enhanced photocatalytic performance of the AgI/Ag₃PO₄/WO₃·H₂O 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.