A Novel Z-Scheme Ag3PO4/SrTiO3 Heterojunction for Highly Efficient Photocatalytic Degradation

There are still challenges to eliminate and reduce the harmful persistent organic pollutants (POPs) in the water, especially the dye-based POPs. Two big obstacles the Ag 3 PO 4 photocatalyst faces are serious carrier recombination and photocorrosion, which presents a limitation for its application in water purification. Therefore, in this work, a novel Ag 3 PO 4 /SrTiO 3 heterojunction was synthesized by a simple in situ deposition method. Ag 3 PO 4 /SrTiO 3 10:1 exhibits the highest photocatalytic activity with rhodamine B (RhB) degradation of 98.8% in only 20 min and methyl orange (MO) degradation of 97.5% in 80 min under simulated sunlight irradiation, which is much higher than that of pure Ag 3 PO 4 and the mixed photocatalysts. During the photocatalytic reaction, h + and •O 2 − are the main active species, and the charge transfer path is satisfied with the Z-scheme mechanism. Additionally, the possible degradation pathways of RhB and MO were proposed by analyzing the intermediate products via HPLC-MS.