Synthesis, characterization and photocatalytic performance of novel visible-light-induced Ag/BiOI

For the first time, a series of Ag/BiOI photocatalysts with different Ag contents have been synthesized by a hydrothermal combinated with photodeposition method. The as-prepared products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), high-resolution transmission electron micrographs (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS), and photoluminescence (PL) emission spectroscopy. The photocatalytic activities of these Ag/BiOI composites under visible-light irradiation (lambda > 420 nm) were evaluated by the degradation of acid orange II, methyl orange (MO) and rhodamine B (RB). The results revealed that the Ag/BiOI composites exhibited much higher photocatalytic activities than pure BiOI. The Ag amount in the Ag/BiOI composites played an important role in the corresponding photocatalytic properties and the optimized ratio was obtained at 0.6%. The significant enhancement in the Ag/BiOI photoactivity could be ascribed to both the effect of Ag deposits by acting as electron traps and the surface plasma resonance effect of Ag. (C) 2011 Elsevier B.V. All rights reserved.