Photocatalytic activities of Bi2S3/BiOBr nanocomposites synthesized by a facile hydrothermal process

Bi2S3/BiOBr nanocomposites with various weight percents of Bi2S3 were successfully prepared by a facile hydrothermal process at 433 K, and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy, energy dispersive X-ray spectroscopy (EDS), UV-vis diffuse reflection spectra (UV-vis DRS) and nitrogen physisorption studies. The UV and visible photocatalytic activities of the as-prepared Bi2S3/BiOBr samples were evaluated by the photo-degradation of methyl orange (MO) in an aqueous solution. The results showed that the photocatalytic activity of the Bi2S3/BiOBr samples was greatly enhanced, compared with that over pure Bi2S (3) and BiOBr. The enhanced photocatalytic activities could be mainly attributed to the effective transfer of the photogenerated electrons and holes at the heterojunction interface of Bi2S3 and BiOBr, which reduced the recombination of electron-hole pairs, and the mechanism of photocatalytic activity enhancement was discussed. (C) 2013 Elsevier B. V. All rights reserved.