Facile anion-exchange synthesis of BiOI/BiOBr composite with enhanced photoelectrochemical and photocatalytic properties

A facile room temperature anion-exchange strategy was successfully adopted to synthesize the promising double visible-light excited BiOI/BiOBr composite photocatalyst. The X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS) results jointly confirmed the formation of BiOI/BiOBr composite through replacing partial of Br− to I−. Moreover, BiOI/BiOBr composite exhibited much higher photocurrent intensity than pure BiOBr and BiOI, which perfectly coincided with the enhanced photocatalytic activity for the degradation of methyl orange (MO) under visible light (λ>420 nm). It is a prospective strategy for constructing highly efficient bismuth halide based composite to eliminate organic pollutants in water.