Enhanced photocatalytic activities of BiOI/ZnSn(OH)6 composites towards the degradation of phenol and photocatalytic H2 production

BiOI/ZnSn(OH)(6) composite photocatalysts with different weight percents of BiOI were successfully synthesized by a facile and economical deposition method at 80 degrees C and characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy, UV-vis diffuse reflection spectroscopy (UV-vis DRS) and Brunauer-Emmett-Teller (BET) surface area measurements. Photocatalytic reforming of ethanol for H-2 production and photocatalytic degradation of phenol over BiOI/ZnSn(OH)(6) samples were investigated. The results showed that the BiOI/ZnSn(OH)(6) photocatalysts exhibited a coexistence of both tetragonal BiOI and cubic perovskite ZnSn(OH)(6) phases. With increasing BiOI content, the absorption intensity of BiOI/ZnSn(OH)(6) increased in the 280-550 nm region and the absorption edge shifted significantly to longer wavelengths compared with that of pure ZnSn(OH)(6). The 19.7% BiOO/ZnSn(OH)(6) catalyst exhibited obviously higher photocatalytic activity as compared to either pure ZnSn(OH)(6) or BiOI, which could be primarily attributed to the presence of intimate contacts between ZnSn(OH)(6) and BiOI resulted in easier charge transfer and more efficient separation of electron-hole pairs. The photocatalytic mechanism of BiOI/ZnSn(OH)(6) was discussed. (C) 2013 Elsevier B.V. All rights reserved.