Facile hydrothermal synthesis of novel Bi12TiO20-Bi2WO6 heterostructure photocatalyst with enhanced photocatalytic activity

摘要

Novel Bi12TiO20-Bi2WO6 (denoted as BTO-BWO) heterostructure photocatalytic materials were constructed by a facile hydrothermal approach. Firstly, BWO nanosheets were fabricated via a solution-phase preparation route. Secondly, BTO-BWO composite photocatalysts could be readily obtained via a controllable partial precipitate conversion strategy, employing previously-prepared BWO nanosheets as precursors of Bi3+. Experiments revealed that BWO nanoflake was uniformly immobilized onto the exterior of the BTO tetrahedron. The visible-light activities of these products for the decomposition of rhodamine B (RhB) were evaluated. Compared to the single-component photocatalyst such as BTO and BWO, these sillenite-type BTO-BWO hetero structures exhibited higher photocatalytic ability. The effective separation of photo-induced carriers because of matching band positions and intimate interfacial contacts might account for the higher photo-activity of BTO-BWO hybrid structures. Furthermore, the influence of some trapping agents on the photocatalytic property was investigated and photo-induced holes and center dot O-2(-) were verified to play more important roles than center dot OH. A possible photocatalytic degradation mechanism of RhB over BTO-BWO heterostructures was presented. (C) 2015 Elsevier B.V. All rights reserved.