Construction of 2D-2D TiO2 nanosheet/layered WS2 heterojunctions with enhanced visible-light-responsive photocatalytic activity

In this study, 2D-2D TiO2 nanosheet/layered WS2 (TNS/WS2) heterojunctions were prepared via a hydrothermal method. The structure and morphology of the photocatalysts were systematically characterized. Layered WS2 (∼4 layers) was wrapped on the surface of TiO2 nanosheets with a plate-to-plate stacked structure and connected with each other by W=O bonds. The as-prepared TNS/WS2 heterojunctions showed higher photocatalytic activity for the degradation of RhB under visible-light irradiation, than pristine TiO2 nanosheets and layered WS2. The improvement of photocatalytic activity was primarily attributed to enhanced charge separation efficiency, which originated from the perfect 2D-2D nanointerfaces and intimate interfacial contacts between TiO2 nanosheets and layered WS2. Based on experimental results, a double-transfer photocatalytic mechanism for the TNS/WS2 heterojunctions was proposed and discussed. This work provides new insights for synthesizing highly efficient and environmentally stable photocatalysts by engineering the surface heterojunctions.Graphical AbstractThe 2D-2D TNS/WS2 heterojunction was successfully constructed by in-situ growing the layered WS2 on the surface of TiO2 nanosheet. The 2D-2D nanointerfaces boosted the separation of photogenerated carriers, thereby resulting in a higher photocatalytic activity.
Source: Chinese Journal of Catalysis - Category: Chemistry Source Type: research