Bismuth-rich Bi4O5X2 (X = Br, and I) nanosheets with dominant {1 0 1} facets exposure for photocatalytic H2 evolution

Abstract

Until now, BiOBr and BiOI are not used for photocatalytic H2 evolution due to the positive CB position. In this work, bismuth-rich strategy is used to promote the CB position. Bi4O5X2 (X=Br, I) nanosheets with dominant {101} facets exposure are synthesized by molecular precursors hydrolysis route. Bi4O5Br2 and Bi4O5I2 samples were characterized by X-ray diffraction patterns (XRD), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectra (DRS), X-ray photoelectron spectroscopy (XPS) and photoelectrochemical measurements. Bi4O5Br2 displays higher photocatalytic activity than Bi4O5I2 for H2 production. And the H2 evolution rate of Bi4O5Br2 reach 6.81μmolh−1 with the apparent quantum efficiency of 0.93% at 420nm. It is the first work to report photocatalytic H2 production using Bi4O5X2 photocatalysts.