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

Highly efficient visible-light-driven Ag3PO4/WO3 photocatalysts with different mole fractions of Ag3PO4 nanocrystals have been synthesized via an in situ precipitation method. Characterization results showed the in situ growth of finely distributed Ag3PO4 nanocrystals on the surface of the WO3 nanosheets. Under visible light irradiation, the Ag3PO4/WO3 photocatalysts exhibited enhanced photocatalytic activity compared with bare Ag3PO4 or WO3 for the degradation of methyl blue, and the highest activity was reached by the Ag3PO4/WO3 hybrid photocatalyst with 20 at% of Ag3PO4. The observed improvement in photocatalytic activity is associated with the extended absorption in the visible light region resulting from the attached Ag3PO4 nanocrystals, and the effective separation of photo-induced carriers at the Ag3PO4/WO3 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.