Novel Ag3PO4/ZnFe2O4 composite photocatalyst with enhanced visible light photocatalytic activity

• A novel composite photocatalyst Ag3PO4/ZnFe2O4 was first synthesized.
• Ag3PO4/ZnFe2O4 showed enhanced photocatalytic activity under visible-light irradiation.
• 48% of TOC was removed in the Ag3PO4/ZnFe2O4 photocatalytic system for 2,4-DCP degradation.
• Photocatalytic mechanism of the composite based on energy-band theory was proposed.

A novel Ag3PO4/ZnFe2O4 composite photocatalyst with enhanced photocatalytic activity was first synthesized via a solvothermal-liquid phase deposition method. Kinetic studies for the composite toward 2,4-dichlorophenol (2,4-DCP) photodegradation indicated that the Ag3PO4/ZnFe2O4 (mass ratio of Ag3PO4 to ZnFe2O4 is 9:1) showed an apparent rate constant of 0.0378 min−1, which was 9.95 times that of ZnFe2O4 and 3.15 times that of Ag3PO4. Moreover, the mineralization rate of 2,4-DCP expressed by the removal rate of total organic carbon (Δ% TOC) reached approximately 48% during a 70-min irradiation. The photocatalytic mechanism of Ag3PO4/ZnFe2O4 is also discussed and the enhanced photocatalytic activity was attributed to the efficient separation of electron–hole pairs and the tailored size of the composite.