Preparation of point-line Bi2WO6@TiO2 nanowires composite photocatalysts with enhanced UV/visible-light-driven photocatalytic activity

Abstract

Bi2WO6@TiO2 nanowires composite photocatalysts (BWO-TNWS) with point-line structures have been successfully fabricated by hydrothermalsynthesis method, and characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectra (UV–vis DRS), photoluminescence (PL) and electrochemical impedance spectroscopy (EIS). The effects of coupling narrow-band-gap semiconductor Bi2WO6 (BWO) to photocatalytic activity for degrading Rhodamine B (RhB) and Phenol under UV–vis light irradiation were investigated. The results demonstrate that the photocatalytic activities of the prepared photocatalysts are associated with the content of Bi2WO6 (BWO). 20% BWO-TNWS (containing 20wt% BWO) composite exhibits the highest degradation rate for RhB and Phenol up to 78% and 33%, respectively. It can be concluded that the improved photocatalytic performance of the BWO-TNWS composite is mainly ascribed to its high photoinduced charge separation rate resulting from the effective heterojunction structure of BWO and TNWS, as well as the enlarged optical response range owing to coupling narrow-band-gap semiconductor BWO.