A novel BiTiO/AgPO heterojunction photocatalyst with enhanced photocatalytic performance.

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