Novel visible-light TiO2/Bi3O4Br photocatalysts with n-n heterojunction: Highly impressive performance for elimination of tetracycline and dye contaminants

Abstract

Novel TiO2/Bi3O4Br nanocomposites were prepared by hydrothermal approach to develop effective photocatalysts upon visible light for removal of contaminants from water. Different instruments have been used for characterization of physiochemical attributes of the photocatalysts. The results of photocatalytic reactions showed that the binary TiO2/Bi3O4Br (30%) heterostructure, in comparison with TiO2 and TiO2/BiOBr (30%), has excellent photocatalytic ability in the elimination of Rhodamine B (RhB). Additionally, the binary TiO2/Bi3O4Br (30%) photocatalyst exhibited superior activity towards degradations of tetracycline (TC), methylene blue (MB), and malachite green (MG). The capability of the TiO2/Bi3O4Br (30%) nanocomposite in degradation of MG, RhB, MB, and TC is 25.8, 70.1, 65.8, and 11.8-folds greater than TiO2 and 6.9, 22.6, 11.4, and 6.5 times premier than Bi3O4Br, and 2.0, 14.3, 1.50, and 1.80 times as much as TiO2/BiOBr (30%), respectively. The superoxide anion radicals, and also holes play main role during the photodegradation reactions. Such a high performance was ascribed to the facile segregation and migration of photogenerated charge carriers and extended light absorption range to visible light. This study can provide a novel method for the facile preparation of visible-light-promoted photocatalysts using TiO2 to remedy wastewater.