Synthesis of novel 2D-2D p-n heterojunction BiOBr/La2Ti2O7 composite photocatalyst with enhanced photocatalytic performance under both UV and visible light irradiation

In the present work, an efficient composite photocatalyst composed of 2D BiOBr nanoplates and 2D La2Ti2O7 thin nanosheets was synthesized. The photocatalytic performance of the as-obtained samples was investigated by the degradation of dye Rhodamine B and phenol under both UV and visible light irradiation. The results demonstrated that the La2Ti2O7 modified with proper amount of BiOBr nanosheets exhibited high efficiency in the photocatalytic process, and the holes took part in the photo-decomposition reaction as the main radicals. The morphology, crystallization, photo-response and electrochemical properties of the obtained catalysts were characterized to understand the mechanism of high photocatalytic activity. The results illustrated that the high photocatalytic performance could be ascribed to the following reasons. First of all, the decoration of BiOBr enlarged the photoresponce of La2Ti2O7 to visible light region, thus the composite can be activated to generate more electron and hole pairs. Secondly, the formed BiOBr/La2Ti2O7 p-n heterojunction promoted the transfer rate of electrons through the interface and improved the separation efficiency of electron-hole pairs. It is expected that this novel 2D-2D p-n heterostructured photocatalyst would be a promising candidate for environmental remediation. (C) 2016 Elsevier B.V. All rights reserved.