Fabrication of a novel Ag3PO4/WO3·H2O composite with enhanced visible light photocatalytic performance for the degradation of methylene blue and oxytetracycline

A novel Ag 3 PO 4 /WO 3 ·H 2 O composite was prepared by loading Ag 3 PO 4 on WO 3 ·H 2 O substrate via a two-step hydrothermal method and characterized by various analytical techniques. The photocatalytic performance was evaluated by the degradation of methylene blue (MB) and oxytetracycline (OTC) under visible light irradiation. Within 30 min, 98.9 % MB can be degraded by the Ag 3 PO 4 /WO 3 ·H 2 O composite with a molar ratio of 3:1 (3Ag/1W), which is higher than that of individual Ag 3 PO 4 and WO 3 ·H 2 O. The 3Ag/1W photocatalyst also exhibits improved photocatalytic activity for OTC degradation than pure WO 3 ·H 2 O and Ag 3 PO 4 . The improvement of photocatalytic activity would be mainly ascribed to the highly efficient separation of photo-induced electron-hole pairs due to matched band structure, as confirmed by photoluminescence spectra (PL) and photocurrent responses test. According to the experimental results of radical trapping and electron spin resonance (ESR), a possible photocatalytic mechanism of the Ag 3 PO 4 /WO 3 ·H 2 O composite was proposed.