A novel Bi 4Ti 3O 12/Ag 3PO 4 heterojunction photocatalyst with enhanced photocatalytic performance

摘要

In this work, we integrated Ag~(3)PO~(4)with Bi~(4)Ti~(3)O~(12)to form Bi~(4)Ti~(3)O~(12)/Ag~(3)PO~(4)heterojunction nanocomposites by an ion-exchange method. The as-prepared Bi~(4)Ti~(3)O~(12)/Ag~(3)PO~(4)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 Bi~(4)Ti~(3)O~(12)/Ag~(3)PO~(4)heterojunction with obvious interfacial interaction between Bi~(4)Ti~(3)O~(12)and Ag~(3)PO~(4). 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 Bi~(4)Ti~(3)O~(12)and Ag~(3)PO~(4). Rhodamine B (RhB) was chosen as the target organic pollutant to evaluate its degradation behavior over Bi~(4)Ti~(3)O~(12)/Ag~(3)PO~(4)composites under simulated sunlight irradiation. Compared to bare Bi~(4)Ti~(3)O~(12)and Ag~(3)PO~(4)nanoparticles, the composites exhibit a significantly enhanced photocatalytic activity. The highest photocatalytic activity is observed for the 10% Bi~(4)Ti~(3)O~(12)/Ag~(3)PO~(4)composite with 10% Bi~(4)Ti~(3)O~(12)content, which is about 2.6 times higher than that of bare Ag~(3)PO~(4). The photocatalytic mechanism involved was investigated and discussed in detail.