Enhanced visible-light photocatalytic activity and the mechanism study of WO3 nanosheets coupled with Ag3PO4 nanocrystals

Highly efficient visible-light-driven Ag 3 PO 4 /WO 3 photocatalysts with different mole fractions of Ag 3 PO 4 nanocrystals have been synthesized via an in situ precipitation method. Characterization results showed the in situ growth of finely distributed Ag 3 PO 4 nanocrystals on the surface of the WO 3 nanosheets . Under visible light irradiation, the Ag 3 PO 4 /WO 3 photocatalysts exhibited enhanced photocatalytic activity compared with bare Ag 3 PO 4 or WO 3 for the degradation of methyl blue, and the highest activity was reached by the Ag 3 PO 4 /WO 3 hybrid photocatalyst with 20   at% of Ag 3 PO 4 . The observed improvement in photocatalytic activity is associated with the extended absorption in the visible light region resulting from the attached Ag 3 PO 4 nanocrystals, and the effective separation of photo-induced carriers at the Ag 3 PO 4 /WO 3 interfaces. In addition, on the basis of the quenching effects of different scavengers and estimated energy band positions, the mechanism of enhanced photocatalytic activity is proposed.