Dual-pathway charge transfer mechanism of anatase/rutile TiO2-Ag3PO4 hollow photocatalyst promotes efficient degradation of pesticides

Abstract

Exploring high-performance photocatalysts still remains a big challenge due to poor charge separation efficiency. Herein, we prepare a novel anatase/rutile TiO2-Ag3PO4 hollow photocatalyst (A/R-TiO2-Ag3PO4) for addressing this challenge. Microstructural characterization and photoelectric measurements confirm that the synergy of hollow structure and dual-heterojunction can provide abundant active sites and boost efficient charge separation through dual-pathway charge transfer mechanism. The A/R-TiO2-Ag3PO4 photocatalyst exhibits the highest photocurrent density (15.25 µA cm−2), which is 8.4 and 5.2 times than that of A-TiO2-Ag3PO4 (1.82 µA cm−2) and P25-Ag3PO4 (2.93 µA cm−2), respectively. Photo-degradation experiment shows that A/R-TiO2-Ag3PO4 presents a high degradation percentage (98.7 %) of thiamethoxam (THX) within 30 min, which is 1.45 and 1.23 times than that of A-TiO2-Ag3PO4 (68.1 %) and P25-Ag3PO4 (80.7 %), respectively. Furthermore, the degradation percentage of THX by A/R-TiO2-Ag3PO4 is as high as 96.4 % after seven successive cycles, indicating excellent cycling stability. Therefore, this work provides a new insight into exploring other high-performance photocatalysts by combining hollow structure and dual-heterojunction.