Construction of Ag3PO4/TiO2/C with p-n heterojunction using Shiff base-Ti complex as precursor: Preparation, performance and mechanism

Ag3PO4/TiO2/C composite photocatalyst with p-n heterojunction was prepared by ultrasonic assisted in-situ precipitation on the basis of TiO2/C material prepared by pyrolyzing Schiff base-Ti complex (SHI-Ti). The results show that TiO2/C is mainly dispersed around Ag3PO4 particles, which significantly improves the photocatalytic performance and stability of Ag3PO4. The degradation rate of norfloxacin (NOR) and the reaction rate constant are 2.78 and 7.71 times than pure Ag3PO4 under the best conditions. The improvement of the photocatalytic performance and reuse stability of Ag3PO4/TiO2/C benefits from the enhancement of electron transfer capability and the improvement of spectral absorption range by the introduction of TiO2/C as well as the immobilization of Ag3PO4, thereby reducing its dissolution. Moreover, the formation of p-n heterojunction between Ag3PO4 and TiO2/C promotes the migration of photo-generated electrons from Ag3PO4 to TiO2/C that could weaken the photocorrosion of Ag3PO4 and improve the stability.