A novel Bi4Ti3O12/Ag3PO4 heterojunction photocatalyst with enhanced photocatalytic performance

Abstract

In this work, we integrated Ag₃PO₄ with Bi₄Ti₃O₁₂ to form Bi₄Ti₃O₁₂/Ag₃PO₄ heterojunction nanocomposites by an ion-exchange method. The as-prepared Bi₄Ti₃O₁₂/Ag₃PO₄ composites were systematically characterized by means of XRD, SEM, TEM, BET, XPS, UV-vis DRS, EIS, PL spectroscopy, and photocurrent response. SEM, TEM, and XPS results demonstrate the creation of Bi₄Ti₃O₁₂/Ag₃PO₄ heterojunction with obvious interfacial interaction between Bi₄Ti₃O₁₂ and Ag₃PO₄. PL spectra, EIS spectra, and photocurrent responses reveal that the composites display an enhanced separation efficiency of photogenerated electron-hole pairs, which is due to the charge transfer between Bi₄Ti₃O₁₂ and Ag₃PO₄. Rhodamine B (RhB) was chosen as the target organic pollutant to evaluate its degradation behavior over Bi₄Ti₃O₁₂/Ag₃PO₄ composites under simulated sunlight irradiation. Compared to bare Bi₄Ti₃O₁₂ and Ag₃PO₄ nanoparticles, the composites exhibit a significantly enhanced photocatalytic activity. The highest photocatalytic activity is observed for the 10% Bi₄Ti₃O₁₂/Ag₃PO₄ composite with 10% Bi₄Ti₃O₁₂ content, which is about 2.6 times higher than that of bare Ag₃PO₄. The photocatalytic mechanism involved was investigated and discussed in detail.