AgI/Ag3PO4 hybrids with highly efficient visible-light driven photocatalytic activity

Highly efficient visible-light-driven AgI/Ag3PO4 hybrid photocatalysts with different mole ratios of AgI were prepared via an in situ anion-exchange method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) technique. Under visible light irradiation (>420 nm), the AgI/Ag3PO4 photocatalysts displayed the higher photocatalytic activity than pure Ag3PO4 and AgI for the decolorization of acid orange 7 (AO 7). Among the hybrid photocatalysts, AgI/Ag3PO4 with 80% of AgI exhibited the highest photocatalytic activity for the decolorization of AO 7. X-ray photoelectron spectroscopy (XPS) results revealed that AgI/Ag3PO4 readily transformed to be Ag@AgI/Ag3PO4 system while the photocatalytic activity of AgI/Ag3PO4 remained after 5 recycling runs. In addition, the quenching effects of different scavengers displayed that the reactive h+ and O 2 − play the major role in the AO 7 decolorization. The photocatalytic activity enhancement of AgI/Ag3PO4 hybrids can be ascribed to the efficient separation of electron–hole pairs through a Z-scheme system composed of Ag3PO4, Ag and AgI, in which Ag nanoparticles act as the charge separation center.