Ag3PO4/g-C3N4/Zn3(PO4)2 catalyst with ternary heterostructure and Z-scheme/type Ⅱ dual pathway mechanism for high photocatalytic performance

A novel Ag 3 PO 4 /g-C 3 N 4 /Zn 3 (PO 4 ) 2 photocatalyst with ternary heterostructure and Z-scheme/type Ⅱ dual pathway mechanism was synthesized. Scanning electron microscopy and transmission electron microscopy data showed that Ag 3 PO 4 , Zn 3 (PO 4 ) 2 , and g-C 3 N 4 were in close contact, leading to the formation of the ternary heterojunction. Under simulated solar light irradiation, the Ag 3 PO 4 /g-C 3 N 4 /Zn 3 (PO 4 ) 2 photocatalyst efficiently degraded rhodamine B (RhB) and displayed much higher photocatalytic activity than pure Ag 3 PO 4 , g-C 3 N 4 , Zn 3 (PO 4 ) 2 , and Ag 3 PO 4 /Zn 3 (PO 4 ) 2 composite, exhibiting a RhB photodegradation efficiency of ∼91.2 % within 60 min. The quenching effects of different scavengers and electron spin resonance (ESR) experiments demonstrated that reactive h + and·O 2 − species played major roles in the photocatalytic reaction. It was elucidated that excellent photocatalytic activity could be ascribed to the Z-scheme/type Ⅱ dual carrier transfer pathways. Therefore, the formation of a ternary heterostructure system is an efficient method for separating charge carriers and retaining their redox capabilities.