Highly efficient visible-light driven AgBr/Ag3PO4 hybrid photocatalysts with enhanced photocatalytic activity

Highly efficient visible-light-driven AgBr/Ag3PO4 hybrid photocatalysts with different mole ratios of AgBr 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 AgBr/Ag3PO4 photocatalysts displayed the higher photocatalytic activity than pure Ag3PO4 and AgBr for the decolorization of acid orange 7 (AO 7). Among the hybrid photocatalysts, AgBr/Ag3PO4 with 60% of AgBr exhibited the highest photocatalytic activity for the decolorization of AO 7. X-ray photoelectron spectroscopy (XPS) results revealed that AgBr/Ag3PO4 readily transformed to be Ag@AgBr/Ag3PO4 system while the photocatalytic activity of AgBr/Ag3PO4 remained after 5 recycling runs. In addition, the quenching effects of different scavengers displayed that the reactive h(+) and O-2(center dot-) play the major role in the AO 7 decolorization. The photocatalytic activity enhancement of AgBr/Ag3PO4 hybrids can be ascribed to the efficient separation of electron-hole pairs through a Z-scheme system composed of Ag3PO4, Ag and AgBr, in which Ag nanoparticles act as the charge separation center. (C) 2014 Elsevier Ltd. All rights reserved.